Making Sense of the Metadata: Clustering 4,000 Stack Overflow tags with BigQuery k-means
How would you group more than 4,000 active Stack Overflow tags into meaningful groups? This is a perfect task for unsupervised learning and k-means clustering — and now you can do all this inside BigQuery. Let’s find out how.

4,000+ tags are a lot
These are the most active Stack Overflow tags since 2018 — they’re a lot. In this picture I only have 240 tags — how would you group and categorize 4,000+ of them?# Tags with >180 questions since 2018 SELECT tag, COUNT(*) questions FROM `fh-bigquery.stackoverflow_archive.201906_posts_questions`, UNNEST(SPLIT(tags, '|')) tag WHERE creation_date > '2018-01-01' GROUP BY 1 HAVING questions>180 ORDER BY 2 DESC

Hint: Co-occurring tags
Let’s find tags that usually go together:
- ‘javascript’ is related to ‘html’.
- ‘python’ is related to ‘pandas’.
- ‘c#’ is related to ‘.net’.
- ‘typescript’ is related to ‘angular’.
- etc…
CREATE OR REPLACE TABLE `deleting.stack_overflow_tag_co_ocurrence` AS WITH data AS ( SELECT * FROM `fh-bigquery.stackoverflow_archive.201906_posts_questions` WHERE creation_date > '2018-01-01' ), active_tags AS ( SELECT tag, COUNT(*) c FROM data, UNNEST(SPLIT(tags, '|')) tag GROUP BY 1 HAVING c>180 ) SELECT *, questions/questions_tag1 percent FROM ( SELECT *, MAX(questions) OVER(PARTITION BY tag1) questions_tag1 FROM ( SELECT tag1, tag2, COUNT(*) questions FROM data, UNNEST(SPLIT(tags, '|')) tag1, UNNEST(SPLIT(tags, '|')) tag2 WHERE tag1 IN (SELECT tag FROM active_tags) AND tag2 IN (SELECT tag FROM active_tags) GROUP BY 1,2 HAVING questions>30 ) )

One-hot encoding
Now get ready for some SQL magic. BigQuery ML does a good job of hot-encoding strings, but it doesn’t handle arrays as I wish it did (stay tuned). So I’m going to create a string first that will define all the columns where I want to find co-occurrence. Then I can use that string to get a huge table, with a 1 for every time a tag co-occurs with the main one at least certain % of time. Let’s see first a subset of these results:
- ‘javascript’ shows a relation to ‘php’, ‘html’, ‘css’, ‘node.js’, and ‘jquery’.
- ‘android’ shows a relation to ‘java’.
- ‘machine-learning’ shows a relation to ‘python’, but not the other way around.
- ‘multi-threading’ shows a relation to ‘python’, ‘java’, ‘c#’, and ‘android`
- ‘unit-testing’ a relation to almost every column here, except to ‘php’, ‘html’, ‘css’, and ‘jquery’.
SELECT tag1 ,IFNULL(ANY_VALUE(IF(tag2='javascript',1,null)),0) Xjavascript ,IFNULL(ANY_VALUE(IF(tag2='python',1,null)),0 ) Xpython ,IFNULL(ANY_VALUE(IF(tag2='java',1,null)),0) Xjava ,IFNULL(ANY_VALUE(IF(tag2='c#',1,null)),0) XcH ,IFNULL(ANY_VALUE(IF(tag2='android',1,null)),0) Xandroid ,IFNULL(ANY_VALUE(IF(tag2='php',1,null)),0) Xphp ,IFNULL(ANY_VALUE(IF(tag2='html',1,null)),0) Xhtml ,IFNULL(ANY_VALUE(IF(tag2='css',1,null)),0) Xcss ,IFNULL(ANY_VALUE(IF(tag2='node.js',1,null)),0) XnodeDjs ,IFNULL(ANY_VALUE(IF(tag2='jquery',1,null)),0) Xjquery ,SUM(questions) questions_tag1 FROM `deleting.stack_overflow_tag_co_ocurrence` WHERE percent>0.03 GROUP BY tag1 ORDER BY questions_tag1 DESC LIMIT 100
K-means clustering time
Now — instead of using this small table, let’s use the whole table to compute k-means with BigQuery. With this line, I’m creating a one-hot encoding string that I can use later to define the 4,000+ columns I’ll use for k-means:one_hot_big = client.query("""And training a k-means model in BigQuery is really easy:
SELECT STRING_AGG(
FORMAT("IFNULL(ANY_VALUE(IF(tag2='%s',1,null)),0)X%s", tag2, REPLACE(REPLACE(REPLACE(REPLACE(tag2,'-','_'),'.','D'),'#','H'),'+','P'))
) one_hot
FROM (
SELECT tag2, SUM(questions) questions
FROM `deleting.stack_overflow_tag_co_ocurrence`
GROUP BY tag2
# ORDER BY questions DESC
# LIMIT 10
)
""").to_dataframe().iloc[0]['one_hot']
CREATE MODEL `deleting.kmeans_tagsubtag_50_big_a_01` OPTIONS ( model_type='kmeans', distance_type='COSINE', num_clusters=50 ) AS WITH tag_and_subtags AS ( SELECT tag1, %s FROM `deleting.stack_overflow_tag_co_ocurrence` WHERE percent>0.03 GROUP BY tag1 ) SELECT * EXCEPT(tag1) FROM tag_and_subtagsNow we wait — while BigQuery shows us the progress of our training:

Davies–Bouldin index: 1.8530
Mean squared distance: 0.8174
Performance note
Do we really need 4,000 one-hot encoded dimensions to obtain better clusters? Turns out that 500 are enough — and I like the results better. It also reduces the time for training the model in BigQuery from 24 minutes to 3. The same with only 30 dimensions lowers the time to 90 seconds — but I like the results better with 500. More on hyper-parameter tuning below.
Mean squared distance: 0.52332
Get ready for the results: The 50 clusters are…
Now it’s time to see our results. I’ll even look out for some tags I’m interested in: How aregoogle
, amazon
, and azure
represented in each cluster?
These are the 50 groups that k-means clustering found — given the 1-hot encoding of related tags we did earlier in this post. Some results make a lot of sense — while others give great insight into what are the prevalent surrounding technologies to any Stack Overflow tag.
Naming each centroid is always a challenge. Here I used the top 5 centroid weight vectors — see how below.
centroid 45: amazon-web-services, aws-lambda, amazon-s3, amazon-ec2, python
—–
amazon-web-services, amazon-s3, aws-lambda, amazon-ec2, amazon-dynamodb, terraform, aws-sdk, amazon-cloudformation, amazon-redshift, aws-api-gateway, amazon-cognito, boto3, cloud, alexa, amazon-rds, amazon-elastic-beanstalk, amazon-ecs, alexa-skills-kit, amazon-cloudfront, serverless, aws-cli, amazon-iam, amazon-cloudwatch, elastic-beanstalk, amazon-sqs, serverless-framework, amazon-athena, aws-amplify, aws-appsync, amazon-sns, alexa-skill, amazon-route53, amazon, amazon-kinesis, amazon-sagemaker, autoscaling, amazon-elb, amazon-ses, aws-cognito, aws-iot, terraform-provider-aws, api-gateway, amazon-vpc, aws-serverless, aws-codepipeline, aws-codebuild, amazon-rds-aurora, bitnami, amazon-lex, aws-step-functions, aws-code-deploy, aws-iam, aws-fargate, dynamodb-queries, boto
amazon: amazon-cognito, amazon-ses, amazon-redshift, aws-lambda, amazon-ecs, amazon-s3, amazon-web-services, amazon-athena, aws-api-gateway, amazon-rds, amazon, amazon-cloudfront, amazon-lex, aws-iot, amazon-elb, aws-code-deploy, amazon-cloudwatch, aws-cli
centroid 17: android, java, android-layout, android-recyclerview, kotlin
—–
android, json, xml, kotlin, android-studio, android-recyclerview, android-layout, android-fragments, xslt, serialization, android-intent, retrofit2, android-activity, android-room, nullpointerexception, retrofit, gson, android-volley, textview, android-viewpager, xml-parsing, recycler-adapter, android-edittext, android-sqlite, protocol-buffers, xsd, deserialization, android-constraintlayout, android-asynctask, fragment, android-architecture-components, android-livedata, imageview, scrollview, android-databinding, android-glide, android-animation, xquery, xslt-1.0, android-jetpack, android-manifest, navigation-drawer, adapter, bottomnavigationview, xslt-2.0, android-toolbar, onclicklistener, android-tablayout, android-cardview, android-spinner, android-adapter, picasso, android-linearlayout, transformation, android-drawable, android-architecture-navigation, android-imageview, android-custom-view, json-deserialization, android-view, android-actionbar, searchview, biztalk, android-coordinatorlayout, android-lifecycle, android-softkeyboard, floating-action-button, recyclerview-layout, swipe, android-relativelayout, android-xml, android-collapsingtoolbarlayout, android-button, android-scrollview, saxon, android-nestedscrollview, android-styles, xml-namespaces, xsl-fo, android-fragmentactivity, android-dialogfragment, android-viewholder, xml-serialization
centroid 7: android, java, javascript, ios, python
—–
android-gradle, bluetooth, rx-java2, build.gradle, dependencies, rx-java, google-play, sdk, android-ndk, corda, video-streaming, android-emulator, libgdx, android-webview, apk, location, java-native-interface, google-play-services, dagger-2, adb, codenameone, android-8.0-oreo, google-places-api, android-notifications, android-studio-3.0, broadcastreceiver, speech-recognition, arcore, sharedpreferences, streaming, gps, android-service, version, coordinates, androidx, native, sms, here-api, android-camera, android-permissions, uri, android-mediaplayer, locale, vert.x, exoplayer, google-maps-markers, settings, alarmmanager, spinner, proguard, okhttp3, text-to-speech, okhttp, updates, android-camera2, android-source, whatsapp, nfc, share, inputstream, google-fabric, xmpp, calculator, manifest, wifi, mpandroidchart, android-9.0-pie, rx-android, call, android-workmanager, mp4, hls, video-processing, release, barcode, android-support-library, alertdialog, android-viewmodel, dji-sdk, barcode-scanner, filepath, sip, google-cloud-messaging, gradle-plugin, android-arrayadapter, screen, payment, toolbar, google-play-console, dagger, mp3, indexoutofboundsexception, ejabberd, httpurlconnection, libraries, android-proguard, coroutine, h.264, simpledateformat, jacoco, background-process, rtsp, offline, root, sensor, splash-screen, android-bluetooth, android-testing, android-resources, android-tv, emulation, android-bitmap, android-listview, multipart, chromecast, android-broadcastreceiver, video-capture, google-maps-android-api-2, pojo, android-canvas, visibility, broadcast, google-play-games, dao, kotlin-android-extensions, avd, lint, android-jobscheduler, android-library, kotlinx.coroutines, firebase-mlkit, expandablelistview, obfuscation, android-contentprovider, appcelerator, mvp, live-streaming, in-app-billing, android-context, audio-streaming, arabic, android-alertdialog, kotlin-coroutines, zxing, android-videoview, fingerprint, braintree, audio-recording, deprecated, job-scheduling, android-wifi, wear-os, bottom-sheet, android-things, device, marker, right-to-left, google-login, mobile-application, media-player, countdowntimer, opengl-es-2.0, nullable, face-detection, exoplayer2.x, android-8.1-oreo, beacon, drawable, gradlew, mapbox-android, classnotfoundexception, parcelable, android-keystore, voice-recognition, toast, aar, google-places, android-theme, android-progressbar, paging, accelerometer, playback, gradle-kotlin-dsl, samsung-mobile, photo, ibeacon, android-appcompat, noclassdeffounderror, branch.io, rtmp, sceneform, foreground-service, google-cast, appcelerator-titanium, android-widget, logcat, android-pendingintent, android-fileprovider, android-gps, sha1, jodatime, android-sensors, android-appbarlayout, surfaceview, mpeg-dash, android-mvvm
google: google-maps-android-api-2, google-play-services, google-fabric, google-places, google-places-api, google-play-console, google-cast, google-login, google-maps-markers, google-play-games, google-play, google-cloud-messaging
centroid 28: angular, typescript, javascript, angular6, angular5
—–
angular, typescript, angular6, angular5, rxjs, angular-material, angular7, service, observable, routing, angular-cli, components, angular-reactive-forms, karma-jasmine, primeng, ag-grid, angularfire2, angular-material2, ngrx, reactive-programming, httpclient, angular-ui-router, angular-routing, lazy-loading, rxjs6, ngfor, angular-forms, angular-httpclient, angular2-routing, angular-components, angular-router, rx-swift, ng-bootstrap, angular2-forms, angular-universal, angular2-template, angular-services, angular-directive, material, angular4-forms, ngx-bootstrap, typescript2.0, angular2-services, ngrx-store, subscription, rxjs5, angular2-directives, ngrx-effects, angular-material-6, angular-cli-v6, angular-http-interceptors, redux-observable, subscribe, angular-pipe, angular-promise, angular2-observables, reactivex, angular-ngmodel, angular-cdk, tsconfig
centroid 20: apache-spark, java, scala, hadoop, python
—–
apache-spark, scala, pyspark, apache-kafka, hadoop, apache-spark-sql, hive, cassandra, apache-flink, jupyter, hdfs, bigdata, playframework, spark-streaming, sbt, apache-nifi, hiveql, apache-kafka-streams, akka, hbase, pyspark-sql, mapreduce, kafka-consumer-api, rdd, spark-dataframe, amazon-emr, yarn, user-defined-functions, parquet, cassandra-3.0, cluster-computing, avro, databricks, apache-kafka-connect, aws-glue, spark-structured-streaming, flink-streaming, kerberos, apache-zookeeper, sqoop, confluent, presto, kafka-producer-api, impala, akka-stream, hadoop2, apache-spark-mllib, traits, apache-zeppelin, cloudera, datastax, apache-storm, distributed-computing, akka-http, data-modeling, apache-spark-dataset, guice, google-cloud-dataproc, gatling, jmx, hortonworks-data-platform, apache-pig, apache-spark-ml, oozie, azure-databricks, scalatest, cql, playframework-2.6, datastax-enterprise, phoenix, confluent-schema-registry, mesos, implicit, implicit-conversion, ksql, scala-collections, spark-submit, hdinsight, ambari
google: google-cloud-dataproc
amazon: amazon-emr, aws-glue
azure: azure-databricks
centroid 12: bash, python, linux, shell, java
—–
macos, ubuntu, ansible, ssh, raspberry-pi, terminal, vim, raspberry-pi3, subprocess, environment-variables, centos, console, command-line-interface, pipe, arguments, jq, homebrew, iot, applescript, printf, escaping, sftp, windows-subsystem-for-linux, raspbian, exec, redhat, stdout, zsh, alias, wget, eval, paramiko, filenames, glob, command-line-arguments, stdin, remote-access, sudo, file-permissions, slurm, putty, gpio, tar, tmux, rsync, expect, ksh, jsch, scp, ssh-tunnel, cat, portforwarding, openssh
centroid 8: c#, .net, asp.net-core, .net-core, java
—–
logging, exception, error-handling, azure-functions, reflection, configuration, azure-cosmosdb, f#, logstash, exception-handling, azure-web-sites, elastic-stack, azure-service-fabric, console-application, try-catch, wix, azure-application-insights, nunit, core, autofac, xunit, dapper, nest, nhibernate, dotnet-httpclient, nlog, httpwebrequest, serilog, log4net, inversion-of-control, identity, unity-container, webclient, blazor, .net-standard-2.0, system.reactive, clr, type-inference, asp.net-core-signalr, asp.net-core-identity, app-config, masstransit, fluentd, google-cloud-stackdriver, winston, .net-framework-version, ninject, .net-core-2.0, claims-based-identity, syslog, kestrel-http-server
google: google-cloud-stackdriver
azure: azure-cosmosdb, azure-web-sites, azure-functions, azure-application-insights, azure-service-fabric
centroid 18: c#, asp.net, asp.net-mvc, asp.net-core, entity-framework
—–
c#, asp.net, .net, asp.net-mvc, asp.net-core, .net-core, entity-framework, linq, asp.net-web-api, model-view-controller, iis, entity-framework-core, dependency-injection, razor, asp.net-core-2.0, asp.net-core-mvc, wcf, entity-framework-6, json.net, kendo-ui, asp.net-core-webapi, webforms, asp.net-mvc-5, identityserver4, asp.net-identity, asp.net-web-api2, asp.net-core-2.1, asp.net-mvc-4, signalr, odata, kendo-grid, automapper, c#-4.0, web-config, razor-pages, windows-services, moq, ado.net, aspnetboilerplate, ef-code-first, ef-core-2.0, asp.net-core-2.2, linq-to-sql, asp-classic, umbraco, ef-core-2.1, asp.net-ajax, ef-migrations, iis-8, connection-string, windows-authentication, linq-to-entities, repository-pattern, swashbuckle, npgsql, iis-7, dbcontext, hangfire, iis-10, iis-express, model-binding, ef-core-2.2, windows-server-2012, signalr-hub, iis-7.5, linq-to-xml
centroid 10: c#, azure, python, java, javascript
—–
azure, botframework, azure-sql-database, bots, azure-storage, chatbot, timeout, azure-storage-blobs, report, ssrs-2012, azure-data-factory, telegram-bot, azure-web-app-service, expression, azure-logic-apps, ibm-watson, refactoring, domain-driven-design, azureservicebus, gzip, azure-resource-manager, azure-iot-hub, twilio-api, azure-data-factory-2, azure-data-lake, vpn, azure-virtual-machine, microsoft-teams, luis, string-formatting, game-physics, google-assistant-sdk, ssrs-2008, game-development, ads, mesh, windows-7, virtual-reality, vuforia, microsoft-cognitive, azure-webjobs, azure-keyvault, azure-api-management, credentials, directx, facebook-messenger, collision-detection, arm-template, sprite, rdlc, game-engine, azure-search, azure-eventhub, physics, azure-blob-storage, desktop-application, factory, software-design, hololens, u-sql, installer, collision, azure-cli, reporting, google-home, azure-table-storage, azure-cognitive-services, unityscript, startup, azure-bot-service, mysql-connector, ienumerable, qnamaker, instantiation, builder, ssrs-tablix, azure-cosmosdb-sqlapi, azure-stream-analytics, quaternions, reportviewer, skype, azure-machine-learning-studio, azure-servicebus-queues, skype-for-business, ssrs-2008-r2, azure-virtual-network, win-universal-app, azure-log-analytics, unity5, csom, dialogflow-fulfillment
google: google-assistant-sdk, google-home
azure: azure-webjobs, azure-log-analytics, azure-virtual-machine, azure-sql-database, azure-api-management, azure-iot-hub, azure-web-app-service, azure-data-factory-2, azure-table-storage, azure-servicebus-queues, azure-bot-service, azure-virtual-network, azure-data-factory, azure-cognitive-services, azure-blob-storage, azure-storage-blobs, azure-logic-apps, azure-resource-manager
centroid 44: c#, javascript, java, oauth-2.0, php
—–
api, authentication, security, facebook, oauth-2.0, spring-security, cookies, jwt, azure-active-directory, cors, postman, microsoft-graph, login, oauth, microservices, active-directory, ldap, jhipster, authorization, passport.js, keycloak, token, azure-ad-b2c, single-sign-on, passwords, sharepoint-online, telegram, spring-security-oauth2, single-page-application, linkedin, google-signin, openid-connect, session-cookies, owin, csrf, auth0, google-oauth2, saml, access-token, linkedin-api, laravel-passport, saml-2.0, google-authentication, xss, azure-powershell, adal, basic-authentication, azure-ad-graph-api, session-variables, msal, oidc, openid, express-session, bearer-token, logout, refresh-token
google: google-authentication, google-signin, google-oauth2
azure: azure-ad-graph-api, azure-active-directory, azure-powershell, azure-ad-b2c
centroid 19: c#, visual-studio, visual-studio-2017, .net, xamarin.forms
—–
visual-studio, xamarin, xamarin.forms, visual-studio-2017, xaml, uwp, azure-devops, xamarin.android, build, reporting-services, tfs, ssis, xamarin.ios, nuget, visual-studio-2015, msbuild, crystal-reports, windows-installer, nuget-package, mono, cross-platform, azure-pipelines-release-pipeline, .net-standard, mvvmcross, visual-studio-2019, visual-studio-2010, c++-cli, visual-studio-2013, sql-server-data-tools, roslyn, resharper, publish, mstest, .net-assembly, visual-studio-2012, azure-devops-rest-api, tfs2017, azure-pipelines-build-task, visual-studio-mac, tfs2018, tfsbuild, visual-studio-extensions, visual-studio-debugging, visual-studio-app-center, csproj, tfs2015, vsix, azure-mobile-services, picker, tfvc, xamarin.uwp
azure: azure-devops, azure-devops-rest-api, azure-pipelines-release-pipeline, azure-mobile-services, azure-pipelines-build-task
centroid 36: c#, wpf, winforms, javascript, vb.net
—–
wpf, vb.net, winforms, user-interface, listview, charts, events, mvvm, datatable, checkbox, data-binding, datagridview, timer, sapui5, gridview, combobox, binding, drag-and-drop, menu, datagrid, knockout.js, popup, window, textbox, styles, treeview, listbox, telerik, uwp-xaml, devexpress, resources, vb6, user-controls, prism, viewmodel, controls, datetimepicker, webbrowser-control, cefsharp, panel, contextmenu, windows-10-universal, wpfdatagrid, windows-forms-designer, custom-controls, wpf-controls, richtextbox, clickonce, observablecollection, picturebox, mvvm-light, gdi+, menuitem, backgroundworker
centroid 2: c++, c, python, linux, java
—–
c++, c, c++11, templates, assembly, cmake, gcc, memory, opengl, arduino, makefile, visual-c++, boost, c++17, lua, compiler-errors, x86, linux-kernel, memory-management, compilation, memory-leaks, operating-system, io, c++14, fortran, arm, serial-port, cuda, char, language-lawyer, segmentation-fault, clang, linker, stack, gdb, garbage-collection, macros, stl, g++, kernel, embedded, byte, malloc, shared-libraries, out-of-memory, nodes, processing, usb, x86-64, stm32, double, cython, buffer, pthreads, mips, signals, operator-overloading, runtime, gtk, llvm, driver, include, opengl-es, cygwin, operators, bit-manipulation, structure, overloading, nasm, precision, gnu-make, ros, gstreamer, mingw, const, variadic-templates, eigen, heap, gtk3, embedded-linux, esp8266, linux-device-driver, compiler-construction, warnings, cpu, cross-compiling, clion, qt-creator, profiling, ctypes, std, codeblocks, intel, return-value, system, newline, sdl-2, microcontroller, system-calls, pass-by-reference, valgrind, boost-asio, reverse-engineering, dynamic-memory-allocation, move, linker-errors, googletest, c-preprocessor, heap-memory, static-libraries, function-pointers, sdl, template-meta-programming, benchmarking, arduino-uno, libcurl, interrupt, vtk, x86-16, compiler-optimization, constants, stdvector, 64-bit, binaryfiles, bit, swig, quicksort, shared-memory, eclipse-cdt, constexpr, primes, bitwise-operators, x11, shared-ptr, clang++, glfw, binary-search, header-files, singly-linked-list, arduino-esp8266, ld, i2c, main, multiple-inheritance, gnu, smart-pointers, ram, simd, declaration, esp32, preprocessor, elf, undefined-behavior, bison, qtquick2, sfinae, variadic-functions, mingw-w64, unique-ptr, avr, masm, free, typedef, doubly-linked-list, generic-programming, compiler-warnings, glibc, kernel-module, move-semantics, auto, bootloader, c-strings, inline-assembly, ncurses, mmap, stdmap, glm-math, qmake, bit-shift, endianness, cpu-registers, template-specialization, pid, operator-precedence, memory-address
google: googletest
centroid 24: css, html, javascript, bootstrap-4, angular
—–
html, css, jquery, html5, css3, bootstrap-4, twitter-bootstrap, flexbox, sass, datatables, highcharts, html-table, twitter-bootstrap-3, layout, frontend, datepicker, drop-down-menu, css-grid, bootstrap-modal, momentjs, responsive-design, modal-dialog, dropdown, grid, responsive, tabs, font-awesome, navbar, carousel, media-queries, themes, tooltip, alignment, overflow, less, css-position, react-bootstrap, border, accordion, dt, css-transforms, angular-ui-bootstrap, nav, z-index, grid-layout, utc, reactstrap, vertical-alignment, pseudo-element, linear-gradients, mixins, collapse, popover, angular-datatables, angular-flex-layout, centering
centroid 31: delphi, c++, c#, winapi, windows
—–
delphi, winapi, dll, mfc, com, firemonkey, firebird, c++builder, delphi-10.2-tokyo, pinvoke, pascal, indy
centroid 25: django, python, django-models, django-rest-framework, python-3.x
—–
django, django-models, django-rest-framework, django-views, django-forms, django-templates, django-admin, django-queryset, django-orm, django-urls, django-2.0, django-serializer, django-allauth, django-filter, django-class-based-views, django-migrations, serializer
centroid 34: docker, kubernetes, python, google-cloud-platform, java
—–
docker, go, kubernetes, elasticsearch, google-cloud-platform, docker-compose, google-app-engine, dockerfile, deployment, rabbitmq, google-cloud-storage, yaml, airflow, google-kubernetes-engine, containers, kibana, google-compute-engine, google-cloud-dataflow, drupal, virtual-machine, apache-beam, openshift, prometheus, ibm-cloud, grpc, docker-swarm, kubernetes-helm, grafana, gcloud, traefik, google-cloud-datastore, kubectl, load-balancing, google-cloud-sql, kubernetes-ingress, monitoring, google-cloud-pubsub, istio, minikube, nginx-reverse-proxy, speech-to-text, alpine, docker-machine, filebeat, google-translate, google-speech-api, iptables, stackdriver, docker-volume, docker-container, azure-aks, nginx-ingress, daemon, google-cloud-vision, google-vision, azure-kubernetes, google-cloud-composer, openshift-origin, kubeadm, dataflow, amazon-eks, service-accounts, rancher, docker-registry, docker-image, nfs, google-cloud-speech, kops, jupyterhub, rbac, google-cloud-endpoints, standard-sql, google-cloud-build, docker-networking
google: google-cloud-build, google-cloud-datastore, google-speech-api, google-cloud-dataflow, google-cloud-storage, google-cloud-platform, google-kubernetes-engine, google-cloud-sql, google-cloud-speech, google-compute-engine, google-cloud-composer, google-cloud-endpoints, google-cloud-vision, google-vision, google-cloud-pubsub, google-translate, google-app-engine
amazon: amazon-eks
azure: azure-aks, azure-kubernetes
centroid 21: excel, vba, excel-vba, c#, python
—–
excel, vba, excel-vba, google-sheets, ms-access, excel-formula, powerbi, outlook, sharepoint, ms-word, access-vba, office365, apache-poi, sap, dax, formatting, pivot-table, office-js, runtime-error, match, powerpoint, outlook-vba, formula, access, row, vsto, ssas, multiple-columns, powerquery, spreadsheet, vlookup, average, extract, userform, unique, ms-office, excel-2010, word-vba, ms-access-2010, excel-2016, rows, ms-access-2016, onedrive, openxml, powerbi-desktop, copy-paste, transpose, conditional-formatting, office-addins, office-interop, epplus, xlsxwriter, interop, phpspreadsheet, paste, shapes, offset, powerpivot, win32com, powerbi-embedded, export-to-excel, python-docx, countif, array-formulas, autofill, powerpoint-vba, activex, ms-access-2013, solver, m, business-intelligence, xls, ado, ssas-tabular, adodb, xlrd, delete-row, sumifs, openxml-sdk, excel-interop, add-in, excel-2013, worksheet, excel-addins
google: google-sheets
centroid 4: git, github, jenkins, python, docker
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git, jenkins, github, jenkins-pipeline, gitlab, continuous-integration, sonarqube, bitbucket, jenkins-plugins, gitlab-ci, devops, azure-pipelines, svn, version-control, phpstorm, webhooks, repository, travis-ci, jekyll, artifactory, atom-editor, jira, pipeline, github-pages, teamcity, slack, push, gitlab-ci-runner, git-bash, github-api, continuous-deployment, branch, nexus, circleci, workflow, git-merge, diff, jenkins-groovy, clone, git-submodules, gitignore, atlassian-sourcetree, pull-request, bitbucket-pipelines, patch, commit, git-branch, versioning, mercurial, gnupg, git-commit, gerrit, rebase, open-source, githooks, allure, ssh-keys, git-push
azure: azure-pipelines
centroid 33: java, hibernate, spring, spring-boot, jpa
—–
hibernate, jpa, spring-data-jpa, spring-data, solr, orm, transactions, spring-batch, wildfly, mapping, many-to-many, lucene, h2, entity, liquibase, jpql, ejb, hql, multi-tenant, persistence, spring-data-rest, hibernate-mapping, eclipselink, querydsl, one-to-many, spring-transactions, hikaricp, criteria, hibernate-criteria, gorm, ehcache, jpa-2.0, criteria-api, entitymanager, transactional
centroid 39: java, python, c#, node.js, android
—–
http, ssl, sockets, curl, server, networking, websocket, encryption, https, socket.io, proxy, openssl, tcp, ssl-certificate, cryptography, http-headers, certificate, localhost, udp, mqtt, connection, client, ip, reverse-proxy, network-programming, aes, rsa, port, tls1.2, chat, client-server, lets-encrypt, cloudflare, haproxy, real-time, virtualhost, wireshark, keystore, ipc, x509certificate, zeromq, bouncycastle, django-channels, tcpclient, http-proxy, serversocket, telnet, cryptojs, public-key-encryption, private-key, tcp-ip, x509, client-certificates, certbot, tor, multicast
centroid 30: java, rest, spring, spring-boot, javascript
—–
java, spring-boot, spring, rest, maven, eclipse, spring-mvc, tomcat, jsp, jdbc, web-services, soap, servlets, swagger, jackson, java-ee, thymeleaf, netbeans, web-applications, apache-camel, architecture, salesforce, spring-webflux, jersey, httprequest, jax-rs, wsdl, http-post, multipartform-data, tomcat8, soapui, response, resttemplate, cxf, httpresponse, rest-assured, api-design, struts2, soap-client, jstl, restsharp, spring-rest, spring-test, spring-restcontroller, jax-ws, put, endpoint, http-status-codes, struts, spring-web
centroid 22: java, spring-boot, spring, maven, eclipse
—–
gradle, intellij-idea, neo4j, jsf, jar, grails, jboss, spring-cloud, spring-integration, jaxb, internationalization, log4j, eclipse-plugin, swagger-ui, jms, websphere, ant, activemq, vaadin, spring-kafka, pom.xml, log4j2, project-reactor, weblogic, java-11, netty, jetty, maven-3, javamail, crud, java-9, spring-cloud-stream, couchbase, ibm-mq, weblogic12c, datasource, glassfish, hazelcast, logback, osgi, hybris, openapi, project, maven-plugin, netflix-eureka, mybatis, cloudfoundry, reactive, eclipse-rcp, swagger-2.0, slf4j, netflix-zuul, quartz-scheduler, jetbrains-ide, spring-boot-actuator, lombok, spring-jdbc, sonarqube-scan, war, cdi, javabeans, tomcat7, interceptor, swt, java-10, freemarker, spring-boot-test, aop, jdbctemplate, dependency-management, spring-cloud-config, aspectj, spring-aop, flyway, amqp, classpath, spring-jms, jackson-databind, spring-cloud-dataflow, spring-websocket, spring-amqp, pivotal-cloud-foundry, spring-cloud-netflix, cucumber-jvm, executable-jar, spring-integration-dsl, swagger-codegen, tomcat9, spring-data-redis, javadoc, jndi, consul, intellij-plugin, dto, maven-surefire-plugin, hystrix, stomp, bean-validation, gateway, mapstruct, birt, spring-tool-suite, properties-file, jackson2, camunda, springfox, spring-data-neo4j, spring-rabbitmq, spring-session, pydev, xtext, servlet-filters, payara, code-formatting, spring-cloud-gateway
google: google-maps
centroid 15: javascript, angular, android, typescript, visual-studio-code
—–
ionic-framework, npm, visual-studio-code, ionic3, google-maps, cordova, debugging, electron, nativescript, ionic4, ionic2, meteor, autocomplete, geolocation, cordova-plugins, markdown, vscode-settings, phonegap, ide, webstorm, vscode-extensions, decorator, editor, ionic-native, onesignal, keyboard-shortcuts, angular2-nativescript, xdebug, hybrid-mobile-app, intellisense, nativescript-angular, tslint, remote-debugging, html-framework-7, breakpoints, syntax-highlighting, vscode-debugger, pylint, ibm-mobilefirst, jsdoc, nativescript-vue, prettier, windbg, phonegap-plugins, code-snippets, inappbrowser, phonegap-build
centroid 42: javascript, html, c#, android, python
—–
unity3d, image, tkinter, svg, animation, canvas, three.js, chart.js, scroll, 3d, html5-canvas, camera, geometry, css-animations, bitmap, rotation, aframe, icons, glsl, shader, fabricjs, rendering, webgl, css-transitions, transform, png, scrollbar, transition, textures, blender, html2canvas, drawing, mask, linechart, draw, jquery-animate, angular-animations, konvajs, raycasting, webvr
centroid 43: javascript, html, jquery, css, reactjs
—–
d3.js, leaflet, google-maps-api-3, magento, magento2, ethereum, jquery-ui, cakephp, jinja2, primefaces, extjs, ember.js, fullcalendar, maps, ckeditor, mapbox, solidity, materialize, jquery-select2, dialog, angularjs-directive, recaptcha, openlayers, coldfusion, polymer, gis, react-apollo, styled-components, tinymce, progress-bar, geojson, javascript-events, position, apollo-client, undefined, addeventlistener, sharepoint-2013, semantic-ui, amcharts, web-deployment, joomla, settimeout, render, p5.js, openstreetmap, element, instagram-api, parent-child, liquid, mapbox-gl-js, focus, angularjs-ng-repeat, setinterval, react-admin, alert, polygon, dom-events, web-component, textarea, react-select, href, web3, contact-form-7, zoom, facebook-javascript-sdk, refresh, graphql-js, overlay, height, slick, content-security-policy, jqgrid, html5-audio, delay, anchor, blogger, html-select, child-process, jquery-plugins, width, html-lists, kendo-asp.net-mvc, loading, zurb-foundation, id, bind, whitespace, dropzone.js, onchange, semantic-ui-react, owl-carousel, media, video.js, hide, netlify, background-color, sticky, geocoding, native-base, webpage, inline, tampermonkey, slick.js, form-data, padding, ternary-operator, event-listener, facebook-messenger-bot, underscore.js, formik, jquery-validate, quill, dc.js, highlight, react-table, electron-builder, bulma, jquery-selectors, fullscreen, multi-select, innerhtml, slideshow, parallax, draggable, footer, styling, react-component, jquery-mobile, selector, swiper, infinite-scroll, contenteditable, sidebar, jquery-ui-datepicker, mobx-react, form-submit, shadow-dom, backbone.js, each, margin, html-form, mathjax, jquery-ui-autocomplete, viewport, c3.js, adsense, sweetalert2, web-development-server, keypress, jquery-ui-sortable, facebook-php-sdk, sweetalert, center, font-awesome-5, react-proptypes, placeholder, summernote, font-face, react-context, web-frontend, ref, css-float, parent, wysiwyg, getelementbyid, font-size, higher-order-functions, lifecycle, dropzone, partial-views, asyncstorage, wai-aria, spfx, custom-element, jstree, bootstrap-datepicker, line-breaks, react-dom, fancybox, css-tables, stylesheet, react-google-maps, react-leaflet, timepicker, option, facebook-marketing-api, gsap, crossfilter, draftjs, directive, fixed, show-hide
google: react-google-maps, google-maps-api-3
centroid 1: javascript, python, html, java, android
—–
wordpress, woocommerce, javafx, swing, google-bigquery, button, google-api, video, google-analytics, plugins, kivy, youtube, onclick, calendar, dynamics-crm, youtube-api, widget, background, slider, radio-button, event-handling, save, amp-html, compression, google-tag-manager, javafx-8, click, hover, fxml, analytics, display, firebase-analytics, mouseevent, resize, background-image, size, listener, google-analytics-api, cross-domain, toggle, jpeg, google-data-studio, google-adwords, rgb, submit, gif, pixel, crop, gallery, tiff, thumbnails, image-resizing, exif, user-experience, src, pillow
google: google-adwords, google-bigquery, google-api, google-tag-manager, google-data-studio, google-analytics-api, google-analytics
centroid 26: javascript, reactjs, node.js, typescript, react-native
—–
javascript, node.js, reactjs, firebase, react-native, flutter, firebase-realtime-database, webpack, dart, redux, google-cloud-firestore, ecmascript-6, react-redux, firebase-authentication, google-cloud-functions, jestjs, promise, async-await, react-router, firebase-cloud-messaging, import, push-notification, dialogflow, material-ui, module, react-navigation, react-native-android, expo, fetch, gulp, mocha, firebase-storage, actions-on-google, create-react-app, enzyme, material-design, jsx, flutter-layout, lodash, babel, navigation, es6-promise, node-modules, apollo, state, npm-install, babeljs, eslint, gatsby, react-native-ios, javascript-objects, react-router-v4, next.js, yarnpkg, webpack-4, react-hooks, redux-form, prestashop, firebase-security-rules, flowtype, react-router-dom, typescript-typings, webpack-dev-server, antd, redux-saga, redux-thunk, router, package.json, react-native-flatlist, firebase-admin, react-props, react-native-navigation, mobx, firebaseui, es6-modules, firebase-hosting, aurelia, pm2, immutability, serverside-rendering, action, setstate, gruntjs, requirejs, ecmascript-5, flutter-dependencies, ssr, react-native-firebase, angular-dart, es6-class, require, laravel-mix, arrow-functions, react-native-maps, npm-scripts, flutter-animation, workbox, firebase-cli, destructuring, babel-loader, immutable.js, minify, browserify, node-sass, nodemon, firebase-security, angularfire, reducers, loader, bower
google: google-cloud-functions, actions-on-google, google-cloud-firestore
centroid 13: javascript, selenium, google-chrome, html, selenium-webdriver
—–
selenium, google-chrome, selenium-webdriver, xpath, dom, google-chrome-extension, firefox, caching, automation, iframe, selenium-chromedriver, mobile, browser, internet-explorer, safari, webdriver, css-selectors, google-chrome-devtools, webrtc, progressive-web-apps, service-worker, local-storage, internet-explorer-11, html5-video, microsoft-edge, ignite, phantomjs, chromium, cross-browser, webdriverwait, capybara, screenshot, cpu-architecture, mobile-safari, firefox-addon, webkit, geckodriver, firefox-webextensions, google-chrome-headless, browser-cache, webdriver-io, v8, specflow, selenium-grid, html-agility-pack, memcached, guava, devtools, cucumber-java, headless, domdocument, extentreports, selenium-ide, watir, cache-control, google-chrome-app, browser-automation, rselenium, mozilla
google: google-chrome, google-chrome-headless, google-chrome-devtools, google-chrome-app, google-chrome-extension
centroid 6: javascript, vue.js, vuejs2, vuex, webpack
—–
vue.js, express, vuejs2, axios, vue-component, vuex, vuetify.js, xmlhttprequest, vue-router, nuxt.js, fetch-api, vue-cli, vue-cli-3, store, nuxt, bootstrap-vue, vue-test-utils, element-ui, vee-validate
centroid 40: mongodb, node.js, javascript, python, express
—–
mongodb, qt, mongoose, graphql, pyqt5, pyqt, mongodb-query, aggregation-framework, discord, qml, qt5, nosql, discord.js, discord.py, aggregate, ejs, handlebars.js, pymongo, backend, schema, mongoose-schema, mean-stack, sails.js, pug, nestjs, loopbackjs, pyqt4, spring-data-mongodb, multer, geospatial, mean, fs, aggregation, lookup, loopback, apollo-server, parse-server, pyside2, bcrypt, mongodb-.net-driver, document, pyside, qt-designer, mongoengine, body-parser, discord.py-rewrite, projection, mern, mongoose-populate, qthread, mlab, joi, passport-local, pyqtgraph, bson, sharding, express-handlebars
centroid 5: multithreading, java, python, concurrency, c++
—–
multithreading, asynchronous, parallel-processing, concurrency, multiprocessing, callback, queue, celery, jvm, task, python-asyncio, synchronization, dask, python-multiprocessing, thread-safety, locking, mpi, openmp, singleton, pickle, python-multithreading, opencl, future, threadpool, mutex, task-parallel-library, tornado, deadlock, aiohttp, atomic, wait, executorservice, semaphore, completable-future, handler, goroutine, channel, race-condition, volatile, pool, runnable, java-threads, synchronous, async.js, producer-consumer, synchronized, java.util.concurrent, blocking
centroid 11: oracle, sql, plsql, oracle11g, database
—–
oracle, plsql, stored-procedures, oracle11g, triggers, db2, oracle12c, sql-server-2014, oracle-sqldeveloper, oracle-apex, cursor, database-trigger, apex, oracle10g, sqlplus, oracle-apex-5.1, procedure, dynamic-sql, cx-oracle, oracle-adf, oracleforms, hierarchical-data, plsqldeveloper, oracle-apex-5
centroid 38: pdf, html, python, php, c#
—–
pdf, merge, webview, printing, fonts, r-markdown, download, base64, puppeteer, itext, hyperlink, latex, export, blob, imagemagick, ocr, pdf-generation, adobe, jspdf, pdfbox, itext7, embed, docx, digital-signature, wkhtmltopdf, fpdf, mpdf, tcpdf, dompdf, ghostscript, acrobat, pypdf2, reportlab
centroid 9: php, laravel, laravel-5, mysql, javascript
—–
php, laravel, ajax, laravel-5, codeigniter, validation, eloquent, session, file-upload, model, pagination, codeigniter-3, laravel-5.6, controller, laravel-5.5, migration, upload, laravel-5.7, laravel-blade, laravel-5.4, relational-database, laravel-5.2, php-7, relationship, lumen, middleware, php-7.2, octobercms, guzzle, image-uploading, laravel-5.8, algolia, query-builder, phpexcel, jobs, laravel-query-builder, laravel-5.3, roles, artisan, laravel-nova, php-carbon, laravel-4, laravel-5.1, homestead, pusher, laravel-eloquent, blade, laravel-routing, laravel-dusk, relation, shared-hosting, eager-loading
centroid 47: php, wordpress, javascript, woocommerce, python
—–
google-apps-script, email, notifications, google-drive-api, paypal, stripe-payments, gmail, smtp, attributes, wordpress-theming, google-calendar-api, google-visualization, google-oauth, google-sheets-api, product, phpmailer, youtube-data-api, advanced-custom-fields, gmail-api, hook-woocommerce, outlook-addin, metadata, google-sheets-formula, cart, html-email, google-app-maker, hook, exchangewebservices, payment-gateway, custom-post-type, exchange-server, checkout, e-commerce, sendgrid, field, content-management-system, nodemailer, categories, gsuite, google-form, admin, mailchimp, comments, web-hosting, outlook-web-addins, orders, wordpress-rest-api, customization, imap, google-docs, rss, custom-wordpress-pages, custom-taxonomy, shortcode, outlook-restapi, email-attachments, google-sheets-query, mailgun, google-api-php-client, woocommerce-rest-api, wordpress-gutenberg, google-apis-explorer, attachment, gmail-addons, price, sendmail, icalendar, blogs, registration, custom-fields, multisite, google-admin-sdk, shipping, gravity-forms-plugin, google-api-client, archive, pagespeed, smtplib, mime, meta, google-api-nodejs-client, contact-form, taxonomy, google-api-python-client, account, stock
google: google-sheets-api, google-docs, google-oauth, google-apps-script, google-sheets-query, google-sheets-formula, google-api-php-client, google-api-nodejs-client, google-visualization, google-admin-sdk, google-calendar-api, google-apis-explorer, google-api-python-client, google-form, google-app-maker, google-api-client, google-drive-api
centroid 23: postgresql, sql, python, javascript, mysql
—–
sqlite, flask, sqlalchemy, hyperledger-fabric, odoo, hyperledger, elixir, blockchain, hyperledger-composer, flask-sqlalchemy, sequence, couchdb, psycopg2, psql, postgis, pyodbc, knex.js, plpgsql, jsonb, jooq, typeorm, postgresql-9.5, ecto, postgresql-10, marshalling, connection-pooling, postgresql-9.6, database-replication, unmarshalling, pgadmin-4, pgadmin, recursive-query, postgresql-9.4, crosstab, go-gorm, database-backups, postgresql-9.3, rds, heroku-postgres
centroid 35: python, java, c++, c#, windows
—–
windows, powershell, batch-file, ffmpeg, audio, cmd, windows-10, path, stream, directory, process, vbscript, prolog, ftp, time-complexity, copy, command, zip, file-io, ocaml, scheduled-tasks, storage, big-o, binary-search-tree, registry, scheme, binary-tree, text-files, dynamic-programming, rename, exe, echo, command-prompt, hashtable, powershell-v3.0, filereader, batch-processing, wmi, stack-overflow, file-handling, windows-server-2016, windows-server-2012-r2, bufferedreader, taskscheduler, fstream, hyper-v, readfile, depth-first-search, fibonacci, ifstream, backtracking
centroid 3: python, java, javascript, arrays, c#
—–
arrays, string, list, function, loops, csv, algorithm, dictionary, performance, for-loop, file, sorting, class, object, if-statement, oop, haskell, recursion, pointers, variables, generics, java-8, matrix, rust, filter, optimization, indexing, math, lambda, arraylist, inheritance, input, multidimensional-array, search, random, vector, data-structures, time, struct, types, methods, while-loop, foreach, design-patterns, dynamic, functional-programming, collections, java-stream, sas, parameters, enums, nested, interface, constructor, linked-list, syntax, casting, tree, hashmap, binary, properties, scope, reference, type-conversion, floating-point, iterator, null, tuples, static, format, set, conditional, iteration, range, switch-statement, return, append, numbers, boolean, output, int, concatenation, polymorphism, hex, compare, initialization, namespaces, integer, pattern-matching, grouping, logic, key, filtering, parameter-passing, list-comprehension, apply, subset, global-variables, slice, vectorization, conditional-statements, combinations, scanf, java.util.scanner, character, lapply, comparison, this, 2d, override, counter, numpy-ndarray, permutation, user-input, rounding, nested-loops, abstract-class, instance, reduce, prototype, itertools, global, reverse, subclass, comparator, key-value, increment, min, infinite-loop, contains, do-while, associative-array, mergesort, abstract, indexof, break, bubble-sort
centroid 48: python, java, javascript, r, php
—–
typo3, wso2, clojure, sublimetext3, drupal-8, acumatica, jframe, docusignapi, teradata, emacs, netsuite, karate, verilog, jasper-reports, marklogic, sparql, vhdl, sympy, autodesk-forge, knitr, erlang, yocto, tcl, odoo-11, cakephp-3.0, mule, phoenix-framework, drupal-7, integration, racket, netlogo, autohotkey, uml, drools, node-red, stata, magento-1.9, common-lisp, aem, opencart, abap, line, python-sphinx, jtable, yii, pentaho, wagtail, coq, regex-lookarounds, slack-api, bioinformatics, openstack, perl6, antlr4, awt, rcpp, upgrade, tweepy, jpanel, macos-high-sierra, documentation, jsonschema, actionscript-3, vmware, wildcard, microsoft-dynamics, prestashop-1.7, typo3-8.x, zend-framework, lisp, gwt, elasticsearch-5, distance, smartcontracts, talend, wso2-am, slim, sfml, message-queue, computer-science, scenebuilder, yii2-advanced-app, rdf, inno-setup, fpga, flask-wtforms, bitcoin, clipboard, special-characters, unreal-engine4, hana, preg-replace, gdal, flash, nginx-config, wso2esb, system-verilog, arangodb, wso2is, netbeans-8, uuid, graphviz, liferay, omnet++, spatial, encode, powershell-v4.0, paypal-sandbox, http2, dynamics-365, local, ip-address, servicestack, hdf5, firewall, kdb, executable, linear-programming, add, orientdb, angularjs-scope, cplex, pymysql, xpages, phaser-framework, maya, powershell-v2.0, nginx-location, adfs, limit, abstract-syntax-tree, variable-assignment, elementtree, wav, mouse, splunk, asterisk, pandoc, publish-subscribe, simulink, webassembly, packages, complexity-theory, ansible-2.x, python-decorators, preg-match, regex-negation, minecraft, spotfire, nested-lists, pcre, gfortran, percentage, matching, monads, jbutton, gsub, numba, sitecore, watson-conversation, dropwizard, edit, frequency, vulkan, cdn, mime-types, wrapper, php-curl, jersey-2.0, scapy, converters, zapier, attributeerror, elm, console.log, web3js, kentico, moodle, intervals, anylogic, multilingual, logical-operators, glm, vlc, owl, autodesk-viewer, dojo, z3, arcgis, classloader, pyomo, sybase, antlr, md5, indexeddb, powerapps, data-conversion, http-status-code-403, web-worker, external, alfresco, airflow-scheduler, finance, typo3-9.x, cpu-usage, pouchdb, ibm-midrange, ping, truffle, qemu, dask-distributed, selection, apache-httpclient-4.x, jsonpath, sha256, coding-style, polymer-2.x, zipfile, vps, symbols, mediawiki, calculation, okta, smarty, blueprism, netcdf, zend-framework3, genetic-algorithm, snmp, repeat, plesk, signature, doxygen, qgis, dlib, jena, ckeditor4.x, tortoisesvn, face-recognition, message, number-formatting, dropbox, lm, default, spss, perforce, assert, uart, acl, symlink, suitescript2.0, kendo-ui-angular2, getter-setter, jira-rest-api, crm, sleep, indentation, prompt, analysis, lme4, ironpython, latitude-longitude, grammar, dotnetnuke, cqrs, gaussian, regex-greedy, koa, yum, numerical-methods, haskell-stack, scala-cats, hugo, rpc, priority-queue, openldap, popen, shapefile, var, partition, record, combinatorics, ada, nio, pentaho-data-integration, appium-ios, scheduling, pyautogui, snakemake, production-environment, lwjgl, computational-geometry, scaling, tabulator, lifetime, naming-conventions, jsf-2, lotus-notes, javac, numeric, odoo-8, modeling, salesforce-lightning, silverstripe, bookdown, websphere-liberty, virtualization, wxwidgets, ramda.js, hapijs, reload, marklogic-9, snapshot, hierarchy, server-side, cakephp-3.x, prestashop-1.6, schedule, unix-timestamp, difference, ontology, readline, configuration-files, opendaylight, block, wolfram-mathematica, rpm, logstash-grok, currency, mount, remote-server, destructor, nsis, captcha, feathersjs, code-generation, hardware, django-2.1, suitescript, typoscript, jython, trim, distributed-system, zabbix, vaadin8, nodemcu, magento2.2, string-matching, shuffle, ckeditor5, mixed-models, fedora, ipv6, new-operator, ember-data, llvm-clang, exit, webcam, str-replace, large-data, simplexml, rules, elasticsearch-aggregation, rhel, dsl, ethernet, event-sourcing, vimeo, hashset, date-formatting, zlib, standards, bamboo, converter, liferay-7, file-get-contents, solrcloud, servicenow, logstash-configuration, xhtml, virtual, pywin32, equals, intersection, micronaut, production, cs50, fopen, elasticsearch-6, lazy-evaluation, server-sent-events, extbase, translate, python-module, tabular, libreoffice, sml, private, apostrophe-cms, tostring, bitbake, actionlistener, restore, activiti, mypy, opencart-3, janusgraph, rank, multiplication, keyword, archlinux, optaplanner, imagick, informix, flex-lexer, photoshop, pyaudio, openlayers-3, reset, sentry, umbraco7, messaging, lotus-domino, fiddler, interactive, jlabel, folium, bigcommerce, transparency, nullreferenceexception, operator-keyword, tracking, keyboard-events, twitter-oauth, static-methods, polymer-3.x, prisma, mule-esb, string-comparison, counting, layout-manager, gherkin, inner-classes, docker-for-windows, checksum, imagemagick-convert, connect, php-7.1, sublimetext, wso2carbon, python-telegram-bot, react-native-router-flux, desktop, paypal-rest-sdk, php-5.6, division, typeclass, identityserver3, mapbox-gl, wix-react-native-navigation, sample, point-clouds, web-audio, vertica, java-time, mosquitto, dllimport, dump, covariance, cytoscape.js, cgal, r-package, installshield, eigen3, point-cloud-library, ngx-datatable, sampling, vapor, clojurescript, auto-increment, overlap, ibm-cloud-infrastructure, echarts, web-audio-api, hp-uft, office365api, ngx-translate, shortcut, paho, ember-cli, rfid, applet, swap, predicate, host, detox, cas, jsf-2.2, trigonometry, sandbox, beagleboneblack, filestream, numpy-broadcasting, xsd-validation, fgets, ghc, serenity-bdd, spi, duration, jna, unzip, fiware, rhel7, long-integer, pentaho-spoon, cpython, crystal-lang, assertion, string-concatenation, compatibility, java-module, fluid, meta-tags, wildfly-10, hashicorp-vault, apache-karaf, roblox, gurobi, install4j, development-environment, static-analysis, ffi, h5py, django-authentication, urlencode, directx-11, salt-stack, r-raster, pseudocode, hsqldb, django-celery, fatal-error, pywinauto, peewee, p2p, tinymce-4, mysql-5.7, openlayers-5, vis.js, palindrome, angular-template, resteasy, kable, quickbooks, monaco-editor, rdp, solrj, file-transfer, language-agnostic, mustache, java-7, naudio, velocity, wikidata, copy-constructor, countdown, wtforms, montecarlo, wso2ei, sitemap, stringbuilder, geoserver, joomla3.0, symbolic-math, bytecode, high-availability, sharepoint-2010, assign, semantic-web, rtf, vmware-clarity, odoo-12, informatica, volume, jit, monogame, super, eof, syncfusion, rust-cargo, dataweave, stack-trace, browser-sync, arduino-ide, blogdown, communication, rider, favicon, fill, processbuilder, biginteger, labview, resampling, normal-distribution, linear, angular4-router, hierarchical-clustering, drag, modbus, diagram, word, org-mode, admin-on-rest, equation, webrequest, tinkerpop3, restful-authentication, lib, tizen, user-agent, survival-analysis, point, fragment-shader, tableau-server, ansible-inventory, delete-file, code-injection, clickhouse, text-editor, kettle, angularjs-material, date-range, rpy2, complex-numbers, graphene-python, coded-ui-tests, midi, programming-languages, web-push, pine-script, equality, holoviews, sapply, quotes, jtextfield, emscripten, sas-macro, angular-http, varnish, phalcon, typing, freeze, opentok, password-protection, anonymous-function, resolution, remote-desktop, cryptocurrency, hpc, default-value, tsc, multiline, chromium-embedded, treemap, substitution, arm64, shutil, supervisord, at-command, interpreter, packet, google-search, dynamics-crm-online, can-bus, neo4j-apoc, ranking, httpserver, gsm, freebsd, centos6, yield, c++-winrt, fread, anypoint-studio, jboss7.x, type-hinting, wixcode, epoch, uninstall, autoit, smartcard, wikipedia, angular-service-worker, cosine-similarity, protege, schema.org, typescript-generics, dropbox-api, verification, composition, windows-server, using, hmac, dry, ag-grid-angular, median, messenger, rethinkdb, thingsboard, xilinx, named-pipes, office-ui-fabric, dynamics-crm-365, heroku-cli, date-format, imputation, jfreechart, wiremock, packaging, outliers, target, typo3-7.6.x, ngrok, audit, models, jboss-eap-7, moving-average, 32bit-64bit, strapi, views, silverstripe-4, rasa-core, content-type, event-loop, textinput, smoothing, surface, explode, getusermedia, 7zip, confidence-interval, watch, freertos, zend-framework2, circular-dependency, qliksense, repeater, cjk, clock, django-testing, pic, csrf-protection, shopping-cart, encapsulation, paypal-ipn, json-ld, cobol, key-bindings, relative-path, hashcode, thrift, bing-maps, localdate, dicom, netezza
google: google-search
centroid 37: python, machine-learning, tensorflow, python-3.x, keras
—–
tensorflow, numpy, keras, machine-learning, opencv, matlab, deep-learning, scikit-learn, image-processing, neural-network, scipy, nlp, pytorch, computer-vision, conv-neural-network, lstm, data-science, regression, classification, dataset, gpu, nltk, google-colaboratory, linear-regression, artificial-intelligence, object-detection, cluster-analysis, generator, spacy, interpolation, logistic-regression, svm, data-analysis, tesseract, random-forest, tensorflow-datasets, bazel, signal-processing, recurrent-neural-network, opencv3.0, fft, tensorboard, gensim, sparse-matrix, word2vec, cv2, h2o, cross-validation, tensor, caffe, xgboost, reshape, reinforcement-learning, stanford-nlp, linear-algebra, k-means, tensorflow-estimator, prediction, rnn, keras-layer, pca, probability, curve-fitting, decision-tree, text-mining, tensorflow-serving, loss-function, object-detection-api, google-cloud-ml, metrics, mathematical-optimization, image-segmentation, matrix-multiplication, autoencoder, tensorflow-lite, r-caret, text-classification, sentiment-analysis, scikit-image, convolution, training-data, categorical-data, tensorflow.js, knn, mnist, valueerror, sklearn-pandas, gradient-descent, weka, yolo, python-tesseract, word-embedding, feature-extraction, tokenize, emgucv, feature-selection, predict, coreml, similarity, normalization, one-hot-encoding, backpropagation, convolutional-neural-network, ode, lda, tf-idf, openai-gym, image-recognition, theano, naivebayes, rasa-nlu, detection, grid-search, data-mining, differential-equations, layer, torch, roc, mxnet, camera-calibration, topic-modeling, cudnn, kaggle, confusion-matrix, tensorflow2.0, doc2vec, distributed, embedding, tfrecord, recommendation-engine, multilabel-classification, ner
google: google-colaboratory, google-cloud-ml
centroid 46: python, php, apache, python-3.x, ubuntu
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apache, nginx, .htaccess, web, url, pip, anaconda, redirect, pycharm, dns, ubuntu-16.04, permissions, url-rewriting, package, mod-rewrite, installation, conda, centos7, ubuntu-18.04, debian, virtualenv, python-import, install, apache2, url-redirection, vagrant, webserver, virtualbox, cpanel, gunicorn, digital-ocean, http-status-code-404, config, hosting, subdomain, systemd, uwsgi, wamp, nvidia, setuptools, ubuntu-14.04, mod-wsgi, pipenv, url-routing, mamp, httpd.conf, environment, query-string, seo, wsgi, subdirectory, setup.py, wampserver, permalinks, pypi, apache2.4, lamp, apt, http-status-code-301, miniconda, http-redirect
centroid 50: python, python-3.x, python-2.7, pandas, javascript
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python, python-3.x, pandas, dataframe, python-2.7, web-scraping, datetime, parsing, beautifulsoup, post, python-requests, scrapy, request, pygame, python-3.6, pandas-groupby, encoding, unicode, get, utf-8, twitter, character-encoding, header, python-3.7, web-crawler, python-imaging-library, pyinstaller, spyder, tags, export-to-csv, typeerror, odoo-10, openpyxl, jsoup, regex-group, python-3.5, ascii, series, urllib, wxpython, lxml, turtle-graphics, xlsx, rvest, nan, argparse, python-2.x, mysql-python, datetime-format, kivy-language, emoji, importerror, screen-scraping, scrapy-spider, pyserial, html-parsing, python-xarray, flask-restful, tkinter-canvas, cheerio, frame, odoo-9, cx-freeze, twisted, tk, python-datetime, python-unicode, decoding, httr, tkinter-entry, timedelta
centroid 16: python, unix, bash, sed, linux
—–
regex, linux, bash, shell, unix, perl, awk, sed, text, replace, split, cron, command-line, grep, scripting, sh, find, substring, filesystems, notepad++, fork, posix, scheduler, cgi, delimiter, text-processing, aix, cut, solaris
centroid 29: r, python, ggplot2, plot, matplotlib
—–
r, matplotlib, ggplot2, dplyr, shiny, jupyter-notebook, plot, graph, time-series, statistics, colors, plotly, julia, rstudio, graphics, seaborn, cypher, tidyverse, bokeh, data-visualization, bar-chart, label, networkx, histogram, ipython, purrr, tidyr, visualization, gremlin, gnuplot, influxdb, igraph, shinydashboard, legend, heatmap, octave, graph-theory, simulation, data-manipulation, correlation, raster, plotly-dash, statsmodels, data-cleaning, na, matlab-figure, mutate, scatter-plot, boxplot, multi-index, stringr, dashboard, forecasting, scale, lubridate, r-plotly, missing-data, graph-databases, arima, pie-chart, graph-algorithm, jupyter-lab, axis, geopandas, shiny-server, distribution, breadth-first-search, sparklyr, bayesian, lag, sf, tibble, subplot, matplotlib-basemap, xts, contour, plyr, anova, axis-labels, shortest-path, shiny-reactivity, ggmap, dijkstra, figure, rlang, facet, ggplotly, zoo
centroid 49: ruby, ruby-on-rails, ruby-on-rails-5, javascript, activerecord
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ruby-on-rails, postgresql, ruby, heroku, redis, ruby-on-rails-5, yii2, hash, activerecord, routes, shopify, ruby-on-rails-4, rspec, rubygems, devise, chef, ruby-on-rails-3, bundle, rails-activestorage, associations, rails-activerecord, puppet, ruby-on-rails-5.2, metaprogramming, rspec-rails, activeadmin, bundler, coffeescript, shopify-app, sidekiq, carrierwave, passenger, sinatra, simple-form, nokogiri, cloudinary, capistrano, puma, webpacker, mongoid, actioncable, erb, haml, rake, paperclip, factory-bot
centroid 41: sql, sql-server, mysql, database, postgresql
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sql, mysql, sql-server, database, tsql, date, mysqli, join, select, group-by, mariadb, sequelize.js, pdo, phpmyadmin, sql-server-2008, data.table, count, sql-server-2012, xampp, database-design, duplicates, view, sum, timestamp, pivot, foreign-keys, sql-update, mysql-workbench, timezone, tableau, insert, ssms, odbc, constraints, sql-server-2016, etl, subquery, max, syntax-error, left-join, case, database-connection, decimal, inner-join, prepared-statement, full-text-search, database-migration, sql-order-by, query-optimization, sql-server-2008-r2, sql-server-2017, sql-insert, union, backup, aggregate-functions, where, partitioning, common-table-expression, distinct, query-performance, concat, oledb, innodb, replication, window-functions, sql-injection, mdx, primary-key, greatest-n-per-group, where-clause, database-performance, sql-delete, data-warehouse, rdbms, sql-like, database-administration, ddl, entity-relationship, bulkinsert, ssis-2012, calculated-columns, resultset, derby, database-schema, sql-server-2005, create-table, database-normalization, temp-tables
centroid 14: swift, ios, xcode, objective-c, android
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ios, swift, xcode, objective-c, uitableview, swift4, iphone, uicollectionview, facebook-graph-api, realm, bluetooth-lowenergy, twilio, core-data, cocoa, admob, cocoapods, alamofire, arkit, swift3, crash, uiview, tableview, localization, keyboard, autolayout, sprite-kit, frameworks, uiviewcontroller, augmented-reality, uikit, wkwebview, scenekit, accessibility, closures, in-app-purchase, instagram, xcode10, uinavigationcontroller, avfoundation, uibutton, apple-push-notifications, uiscrollview, uitextfield, delegates, crashlytics, app-store, uicollectionviewcell, ios11, protocols, macos-mojave, ios12, xcode9, storyboard, uinavigationbar, qr-code, uilabel, uiimageview, uitabbarcontroller, ipad, optional, decode, uiimage, cell, metal, segue, mapkit, deep-linking, swift4.2, parse-platform, codable, spotify, uitextview, avplayer, itunesconnect, facebook-login, gradient, touch, audiokit, cocoa-touch, textfield, assets, ios-simulator, uistackview, uisearchbar, uiwebview, grand-central-dispatch, firebase-dynamic-links, watchkit, voip, nslayoutconstraint, fastlane, uiimagepickercontroller, iphone-x, nsattributedstring, interface-builder, viewcontroller, uipickerview, nsuserdefaults, core-bluetooth, decodable, xctest, extension-methods, apple-watch, nsurlsession, core-location, code-signing, navigationbar, uialertcontroller, orientation, uigesturerecognizer, objectmapper, swift-playground, keychain, core-graphics, xib, uisearchcontroller, lldb, swift-protocols, avaudioplayer, tvos, cloudkit, shadow, appdelegate, contacts, statusbar, swift4.1, testflight, mkmapview, ios-autolayout, uibezierpath, gesture, uipageviewcontroller, health-kit, uitabbar, cllocationmanager, calayer, xcuitest, provisioning-profile, icloud, uicollectionviewlayout, geofire, uistoryboard, metalkit, pdfkit, plist, uiviewanimation, swifty-json, collectionview, uibarbuttonitem, ipa, xcode-ui-testing
centroid 32: symfony, php, symfony4, javascript, mysql
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forms, symfony, symfony4, composer-php, twig, doctrine, annotations, doctrine-orm, phpunit, symfony-3.4, translation, autowired, symfony-forms, sonata-admin, api-platform.com, fosuserbundle, swiftmailer, data-annotations, sonata
centroid 27: testing, java, javascript, unit-testing, automated-tests
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angularjs, unit-testing, testing, groovy, junit, jmeter, protractor, mockito, automated-tests, jasmine, mocking, cucumber, appium, pytest, testng, robotframework, integration-testing, cypress, performance-testing, android-espresso, code-coverage, e2e-testing, junit5, chai, python-unittest, junit4, sinon, karma-runner, ui-automation, load, appium-android, nightwatch.js, load-testing, tdd, katalon-studio, testcafe, jest, bdd, spock, powermockito, powermock, codeception, jmeter-plugins, rpa, qa, cucumberjs, jmeter-4.0, angular-test, robolectric
Full code
The code I used to create and display the previous results:clusters = 50 percent = '01' one_hot_dimensions = 50 model = 'deleting.kmeans_tagsubtag_%s_big_a_%s_%s' % (clusters, percent,one_hot_dimensions) clusters_temp_table = 'deleting.clusters_%s_result_a_%s_%s' % (clusters, percent, one_hot_dimensions) one_hot_p = client.query(""" SELECT STRING_AGG( FORMAT("IFNULL(ANY_VALUE(IF(tag2='%%s',1,null)),0)X%%s", tag2, REPLACE(REPLACE(REPLACE(REPLACE(tag2,'-','_'),'.','D'),'#','H'),'+','P')) ) one_hot FROM ( SELECT tag2, SUM(questions) questions FROM `deleting.stack_overflow_tag_co_ocurrence` GROUP BY tag2 ORDER BY questions DESC LIMIT %s )""" % one_hot_dimensions).to_dataframe().iloc[0]['one_hot'] client.query(""" CREATE OR REPLACE MODEL `%s` OPTIONS ( model_type='kmeans', distance_type='COSINE', num_clusters=%s ) AS WITH tag_and_subtags AS ( SELECT tag1, %s FROM `deleting.stack_overflow_tag_co_ocurrence` WHERE percent>0.%s GROUP BY tag1 ) SELECT * EXCEPT(tag1) FROM tag_and_subtags """ % (model, clusters, one_hot_p, percent)).to_dataframe() df = client.query(""" CREATE OR REPLACE TABLE %s AS WITH tag_and_subtags AS ( SELECT tag1, MAX(questions) questions, %s FROM `deleting.stack_overflow_tag_co_ocurrence` WHERE percent>0.%s GROUP BY tag1 ) SELECT centroid_id , STRING_AGG(tag1, ', ' ORDER BY questions DESC) tags , ARRAY_TO_STRING(ARRAY_AGG(IF(tag1 LIKE '%%google%%', tag1, null) IGNORE nulls LIMIT 18), ', ') google_tags , ARRAY_TO_STRING(ARRAY_AGG(IF(tag1 LIKE '%%amazon%%' OR tag1 LIKE '%%aws%%', tag1, null) IGNORE nulls LIMIT 18), ', ') amazon_tags , ARRAY_TO_STRING(ARRAY_AGG(IF(tag1 LIKE '%%azure%%', tag1, null) IGNORE nulls LIMIT 18), ', ') azure_tags , COUNT(*) c FROM ML.PREDICT(MODEL `%s` , (SELECT * FROM tag_and_subtags ) ) GROUP BY 1 ORDER BY c DESC """ % (clusters_temp_table, one_hot_p, percent, model)).to_dataframe() df = client.query(""" SELECT centroid_id, c, yep, tags , IFNULL(google_tags, '') google_tags , IFNULL(amazon_tags, '') amazon_tags , IFNULL(azure_tags, '') azure_tags FROM `%s` JOIN ( SELECT centroid_id , STRING_AGG(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(feature,'_','-'),'D','.'),'H','#'),'P','+'), 'X', ''), ', ' ORDER BY numerical_value DESC LIMIT 5) yep FROM ML.CENTROIDS(MODEL `%s` ) GROUP BY 1 ) USING(centroid_id) ORDER BY yep """ % (clusters_temp_table, model)).to_dataframe() for index, row in df.iterrows(): print('centroid %s: %s\n-----' % (row['centroid_id'], row['yep'])) print(row['tags']) print() if row['google_tags']: print('google: %s' % row['google_tags']) if row['amazon_tags']: print('amazon: %s' % row['amazon_tags']) if row['azure_tags']: print('azure: %s' % row['azure_tags']) print('\n')Note that I joined my results with
ML.CENTROIDS()
— which gives me the top differentiating occurring tags for each centroid — even if they are not part of each cluster.
And that’s all it takes
Are you surprised by the results? Or surprised by how easy was to run our k-means modeling with BigQuery? Or curious for why I chosedistance-type: 'COSINE'
for this problem? Now it’s your turn to play :).
Check the BigQuery docs for creating models and the k-means tutorial.
Lak’s thoughts
How would you choose the best parameters? Check Lak Lakshmanan post for hyper-parameter tuning. Lak also had some interesting ideas about dimensionality reduction for clustering via matrix factorization — but we’ll leave that for a future post. As an untested preview: Once you have the co-occurrence of tag1 and tag2, treat it as a recommendation problem, i.e. tag2 is what tag1 liked percent of the time. Then, you can do matrix factorization:CREATE OR REPLACE MODEL deleting.tag1_tag2From this matrix factorization, you will have tag1_factors and tag2_factors which are essentially an embedding of the tags learned from the data. Concatenate these and cluster it instead …
OPTIONS (
model_type='matrix_factorization',
user_col='tag1', item_col='tag2', rating_col='percent10' )
AS
SELECT tag1, tag2, percent*10 AS percent10
FROM advdata.stack_overflow_tag_co_ocurrence
SELECT feature, factor_weights
FROM ML.WEIGHTS( MODEL deleting.tag1_tag2 )
WHERE processed_input = 'tag1' and feature LIKE '%google%'
6 Comments
That centroid 48 (python, java, javascript, r, php) contains a huge lot of totally unrelated tags.
k-Means is not actually a *clustering* algorithm; it is a *partitioning* algorithm. That is to say K-means doesn’t ‘find clusters’ it partitions your dataset into as many (assumed to be globular – this depends on the metric/distance used) chunks as you ask for by attempting to minimize intra-partition distances.
I guess it was used because it is fast, and possible to implement in BigQuery ML. Better solution might be to use (almost) parameter-less HDBSCAN algorithm (a density based algorithm). This algorithm also allows for points to not be in any cluster, i.e. for outliers. It is slower than k-Means, though.
See e.g. https://nbviewer.jupyter.org/github/lmcinnes/hdbscan/blob/master/notebooks/Comparing%20Clustering%20Algorithms.ipynb
Dear Felipe, Developer Advocate for Google Cloud:
What explains that blockchain/ethereum is in the top visualization, but not ios/swift? Is there a bias somewhere?
Great writeup, I really like how you shared the queries!
As an analyst myself, I’d report out in somewhat more condensed fashion. For fellow analysts it is interesting to understand why you made the decision on more than 180 posts per keyword. My guess is frequency analysis and a clear cutoff pattern for it. That’s where you’ve lost the management person in the audience normally 😀
For the 50 centroids as an outcome for k-means analysis, I’d summarize with the centroid name and would ‘collapse’ with a spoiler or other type of content hiding feature the full list of centroid tags.
I’m missing a remark on the centroid tags; as for example you mention that python is related to pandas. However, pandas is a smaller subset related to python development, but there is a hierarchy in this. Pandas does not exist without python, python can exist without Pandas. Sometimes we use in our analysis an exclusion, so all items with only one tag will be central. There still might be some ‘pollution’ in that set, as not all question posters have included all related tags that might be relevant.
In any case, thanks for making such an elaborate and open presentation, it really helps the research field forward!
So… learning algs will always make mistakes… on computer and in meat… but these are fun, but not useful.
`centroid 7: android, java, javascript, ios, python` -> have fun parsing out what the what version of java to run on you python ios device…
`c++, c, python, linux, java` -> yup those are popular things…
I suspect that the methodology allows something like `linux` to bridge unrelated C/Java … as there is probably large co-occurrence with linux/C and linux/Java, but probably very low co-occurrence with C/Java.
i want to implement prepaid balance process with NFC using spring boot +angular7.
but i did’t get any information related to this. means this integration(spring boot +angular7) is possible or not .
please help…