This work is supported by Anaconda Inc. and the Data Driven Discovery Initiative from the Moore Foundation. Anaconda is interested in scaling the scientific python ecosystem. My current focus is on out-of-core, parallel, and distributed machine learning. This series of posts will introduce those concepts, explore what we have available today, and track the community’s efforts to push the boundaries. You can download a Jupyter notebook demonstrating the analysis here....

I’m faced with a fairly specific problem: Compute the pairwise distances between two matrices $X$ and $Y$ as quickly as possible. We’ll assume that $Y$ is fairly small, but $X$ may not fit in memory. This post tracks my progress.

Today I released stitch into the wild. If you haven’t yet, check out the examples page to see an example of what stitch does, and the Github repo for how to install. I’m using this post to explain why I wrote stitch, and some issues it tries to solve. Why knitr / knitpy / stitch / RMarkdown? Each of these tools or formats have the same high-level goal: produce reproducible, dynamic (to changes in the data) reports....

This is part 7 in my series on writing modern idiomatic pandas. Modern Pandas Method Chaining Indexes Fast Pandas Tidy Data Visualization Time Series Scaling Timeseries Pandas started out in the financial world, so naturally it has strong timeseries support. The first half of this post will look at pandas’ capabilities for manipulating time series data. The second half will discuss modelling time series data with statsmodels. %matplotlib inline import os import numpy as np import pandas as pd import pandas_datareader....

This is part 6 in my series on writing modern idiomatic pandas. Modern Pandas Method Chaining Indexes Fast Pandas Tidy Data Visualization Time Series Scaling Visualization and Exploratory Analysis A few weeks ago, the R community went through some hand-wringing about plotting packages. For outsiders (like me) the details aren’t that important, but some brief background might be useful so we can transfer the takeaways to Python. The competing systems are “base R”, which is the plotting system built into the language, and ggplot2, Hadley Wickham’s implementation of the grammar of graphics....

This is part 5 in my series on writing modern idiomatic pandas. Modern Pandas Method Chaining Indexes Fast Pandas Tidy Data Visualization Time Series Scaling Reshaping & Tidy Data Structuring datasets to facilitate analysis (Wickham 2014) So, you’ve sat down to analyze a new dataset. What do you do first? In episode 11 of Not So Standard Deviations, Hilary and Roger discussed their typical approaches. I’m with Hilary on this one, you should make sure your data is tidy....

This is part 3 in my series on writing modern idiomatic pandas. Modern Pandas Method Chaining Indexes Fast Pandas Tidy Data Visualization Time Series Scaling Indexes can be a difficult concept to grasp at first. I suspect this is partly becuase they’re somewhat peculiar to pandas. These aren’t like the indexes put on relational database tables for performance optimizations. Rather, they’re more like the row_labels of an R DataFrame, but much more capable....

This is part 4 in my series on writing modern idiomatic pandas. Modern Pandas Method Chaining Indexes Fast Pandas Tidy Data Visualization Time Series Scaling Wes McKinney, the creator of pandas, is kind of obsessed with performance. From micro-optimizations for element access, to embedding a fast hash table inside pandas, we all benefit from his and others’ hard work. This post will focus mainly on making efficient use of pandas and NumPy....

This is part 2 in my series on writing modern idiomatic pandas. Modern Pandas Method Chaining Indexes Fast Pandas Tidy Data Visualization Time Series Scaling Method Chaining Method chaining, where you call methods on an object one after another, is in vogue at the moment. It’s always been a style of programming that’s been possible with pandas, and over the past several releases, we’ve added methods that enable even more chaining....

This is part 1 in my series on writing modern idiomatic pandas. Modern Pandas Method Chaining Indexes Fast Pandas Tidy Data Visualization Time Series Scaling Effective Pandas Introduction This series is about how to make effective use of pandas, a data analysis library for the Python programming language. It’s targeted at an intermediate level: people who have some experience with pandas, but are looking to improve. Prior Art There are many great resources for learning pandas; this is not one of them....