Sequential writes leveldb versus system_x

OK, calling it a benchmark is a bit of an overstatement. It’s taking two different database libraries for a quick spin, and seeing how fast they can write a bunch of integers to disk. A second benchmark checks how fast we can read them.

In this mini-test, I’m running leveldb against a new embedded database library, let’s call it system_x. The purpose is really just so that I can remember some rough numbers regarding these useful database libraries.

I used the time command to gather results, which shows real, user and sys time spent.

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Plotting data on maps with matplotlib

I’m learning about matplotlib, and actually just bought the book Matplotlib for Python Developers.

Geographical plots

Browsing stackoverflow, the matplotlib homepage, and other resources, I eventually came by this stackoverflow post, which mentions BaseMap. Since the data that I’m plotting is inherently geographical, it makes sense to show the data on a map.

There are several nice examples on the basemap Github page.


Often I want to create heatmaps of the data, using matplotlib.

On stackoverflow there are several posts on this topic:

There are different colormaps available for matplotlib, if you want to try different colorschemes.

How to install gfortran on Mac OS X

Why did I install gfortran? Well, not to write Fortran programs. I tried installing SciPy using pip install scipy, and I got a message that a Fortran compiler was needed.


This is how I installed gfortran on my Mac:

Visit, and select a binary distribution for your version of Mac OS X, e.g. gfortran-snwleo-intel-bin.tar.gz for Snow Leopard.

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