## Pyspark Joins by Example

Summary: Pyspark DataFrames have a join method which takes three parameters: DataFrame on the right side of the join, Which fields are being joined on, and what type of join (inner, outer, left_outer, right_outer, leftsemi). You call the join method from the left side DataFrame object such as df1.join(df2, df1.col1 == df2.col1, ‘inner’).

## Why Saying a ‘One Unit Increase’ Doesn’t Work in Logistic Regression

Summary: Logistic regression produces coefficients that are the log odds. Take e raised to the log odds to get the coefficients in odds. Odds have an exponential growth rather than a linear growth for every one unit increase. A two unit increase in x results in a squared increase from the odds coefficient. To get […]

## Working with arules transactions and read.transactions

Summary: The simplest way of of getting a data.frame to a transaction is by reading it from a csv into R. An alternative is to convert it to a logical matrix and coerce it into a transaction object.

## Before Scaling – Building Analytical Team Processes

Summary: Before adding a person to your analytical team, it’s important to create templates for reporting, centralize data access, and automating reoccurring reports.

## Pyspark ALS and Recommendation Outputs

Lately, I’ve written a few iterations of pyspark to develop a recommender system (I’ve had some practice creating recommender systems in pyspark). I ran into a situation where I needed to generate some recommendations on some different datasets. My problem was that I had to decipher some of the prediction documentation. Because of my struggles, […]