Keith Yap

Things I've Learnt

Remote login to Heroku

Open terminal, navigate to project folder, assume Heroku CLI and Git installed heroku loginheroku git:remote -a ‘name of heroku project’ If using a database: heroku addons:create heroku-postgresql:hobby-devheroku pg:psql

Ranking in SQL

Rank results by the values in a column: SELECT *, RANK() OVER (PARTITION BY column1 ORDER BY column2 DESC) AS rnkFROM table Restrict the number of results to return only the top or bottom X results SELECT *, RANK() OVER… Continue Reading →

Exluding SQL results with Left Outer Join

Imagine you have a data set ‘a’ which contains data from another data set ‘b’. You want to retrieve the data that exists in ‘a’ but not in b. This can be accomplished using a left outer join filtering on… Continue Reading →

Multiple trended fallouts in a single graph in Adobe Workspace

Adobe Analytics Workspace makes it extremely easy for anyone to build decent looking, dynamic graphs and charts. Yet, if you are trying to visualise something that doesn’t fit within the constraints arbitrarily determined by Adobe, you’re going to have a… Continue Reading →

Cohort analysis: Adobe Analytics vs Tableau

Cohort analysis is useful to track changes in groups of metrics over time. A good example is user engagement – do users who joined in January stay as engaged as users who joined in October? However, depending on how your… Continue Reading →

Reading Notes – Maths and Stats for Web Analytics and Conversion Optimization

The following are notes from my readthrough of Maths and Stats for Web Analytics and Conversion Optimization by Himanshu Sharma, in no particular order: ROI, ROI, ROI You need 4 sets of data to calculate ROI: (1) Cost data (2)… Continue Reading →

Data visualisation with Python and Plotly – The Perth real estate market

Python is well known for its data science and analysis capabilities with packages such as Numpy, Matplotlib and Pandas. Each of these packages also offer a variety of graphing and visualisation tools, the majority of which is already very well… Continue Reading →

House Purchase Calculator – WA

The below spreadsheet can be used to check key metrics before purchasing a property. All cells in orange are to be filled in with your own values. Everything else is calculated.

Remote connection to Raspberry Pi

Easy SSH when your computer and your PI are on the same network (wifi) Mac/Linux: Open the terminal Windows: Install Putty Ensure the pi is turned on and connected to network Find the ip address of the pi SSH into… Continue Reading →

PostgreSQL Beginner’s Cheat Sheet

Terminal commands: Launch PostgreSQL terminal – psql Copy table from one db to another – pg_dump -t table_name copyfrom_db_name | psql copyto_db_name   PSQL commands: List databases – \d List tables in current database – \dt List table structure – \d table_name List… Continue Reading →

« Older posts

© 2020 Keith Yap — Powered by WordPress

Theme by Anders NorenUp ↑