## Another Beamer Theme Matrix

The Beamer $\LaTeX$ package for creating presentation slides has hundreds of styles available between all of the combinations of its included themes and color themes. Therefore, it is helpful to be able to look through all the possibilities in order to choose a style. A resource for this exists, the Beamer Theme Matrix; however, its load times lead much to be desired, particularly on a slower Internet connection. It uses two separate images for each combination, causing the browser to make over 800 requests to the server. This, combined with a page size of approximately 6.6MB, causes page load times in excess of 10 seconds on a fast connection and over a minute on a slow one. To remedy this, I created Another Beamer Theme Matrix. The page is less than 1MB and causes the browser to make fewer than 40 requests to the server, resulting in load times of under a second on a fast connection and under 10 seconds on a slow one, an order of magnitude improvement. This is accomplished by combining the thumbnails for each color theme of a particular theme into a single PNG sprite, which is then reduced to 8-bit color using pngquant and further optimized using OptiPNG. To further increase usability of the matrix, small bits of JavaScript were used to always keep the row and column labels visible, a lightbox was added for viewing the full-size previews, and a welcome and help screen was added that explains the matrix and how to use values from the matrix in a $\LaTeX$ document.

Another Beamer Theme Matrix’s source code is available under an MIT license on GitHub. While inspired by the existing Beamer Theme Matrix, it is a complete rewrite in Python.

## Using Marine Gravity Anomaly Map with Mapbox GL

Yesterday, a paper was published in Science on the creation of new, higher resolution maps of the ocean floor using gravity anomaly data collected via satellite. The authors write, “at scales smaller than 200 km, variations in marine gravity primarily reflect sea-floor topography.” Since rock has a different density than water, precise gravity measurements allow for an estimation of ocean depth. One of my first thoughts was to use this data in a map.

The authors provide their data for download; however, it is provided as GMT grid files, which are apparently common for oceanography research, instead of something more standard for GIS such as GeoTIFF. Using GMT, I was able to convert the data to the GDAL supported NetCDF format, although I had to reencode the file with CDO before GDAL would handle it. Using GDAL, I then reprojected the data in EPSG:3857, converted it from floating point to integer, and created a GeoTIFF file to be more friendly to web mapping applications.

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## Nugacious

Finding random comparisons interesting and being disappointed with the limited and deterministic nature of Wolfram Alpha’s quantity comparisons, I created Nugacious to make random comparisons between physical quantities. Using a set of about 700,000 physical quantities extracted from DBpedia, an ontology created from Wikipedia infoboxes, an essentially limitless number of random comparisons are provided with links to their source Wikipedia pages for your reading pleasure. Try it today!