Colorgorical is an alternative to ColorBrewer with a few different options for creating color tables. For example, you can add a couple specific colors that should be in the color table and let Colorgorical figure out the others which maximizes the perceptual difference between the colors. Colorgorical seems particularly well suited to generating qualitative color tables, e.g., to find sufficiently different colors for each line in a plot.

via FlowingData.

Motivated by the below chart of the age distribution of Olympic athletes, Junk Charts presents several techniques to visualize multiple distributions:

Age distribution of Olympic athletes

Candidates include the traditional boxplots used by statisticians as well variations and a stack of histograms. I think violin plots, suggested by a commenter, are a nice compromise showing the full distribution.

It is often useful to display a progress bar showing the state of a task. MG_Progress can easily be used to display a progress bar, percent completion, and estimated time to completion. As a simple example, let’s pretend to load 100 items (while actually just waiting a bit):

foreach i, mg_progress(indgen(100), title='Loading') do wait, 0.1

The above line produces the following output:

Code for mg_progress__define is on GitHub (you will need mg_statusline also). See the code docs for the many other options that can be used with MG_Progress like dealing with a list of items that don’t all take equal time and customizing the display.

John Nelson produced this beautiful map of how the boundaries of US droughts have changed over the last five years with data from the US Drought Monitor:

Link via FlowingData.

Part 2 (of what promises to be a four part series) of the great comparison of Google Maps and Apple Maps by Justin O’Beirne. See part 1 before starting with part 2.

This is an example of using a clever color key that doubles as a histogram showing the distribution of the corresponding areas.

By the way, this post is from a great series about small ways to make better visualizations.

Great post examining some of the reasons why the FFT algorithm is so fast compared to a naive implementation:

The goal of this post is to dive into the Cooley-Tukey FFT algorithm, explaining the symmetries that lead to it, and to show some straightforward Python implementations putting the theory into practice. My hope is that this exploration will give data scientists like myself a more complete picture of what’s going on in the background of the algorithms we use.

A nice list of resources for doing remote sensing in Python, especially if you already know IDL.

Nice example of why rainbow color tables can be misleading:

Regular readers will be aware of the #endrainbow campaign to reduce the use of rainbow colour palettes in scientific figures. At the recent EGU conference, I gave a talk on ‘making better figures’, which included an example of a published conclusion which was incorrect due to the use of a rainbow colour scheme.

via @asoconnor via @rsimmon

This is a great article about the change in balance between cities and roads in Google Maps between 2010 and 2016.

He also compares Google Maps versions to an old printed map:

Even though it’s from the early 1960s, the old map is more balanced than the Google map.

There are a lot of visualization lessons to be learned from cartography.

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