Things I wish I had known about Raspberry Pis

Raspberry Pis are very fun to play with and are relatively cheap —I believe I have 6 or 7 Pis running across the house. However, very often I learnt a thing or two that I wish I had known beforehand —sometimes rather fortuitously. So here is my list of top "in-hindsight" tips from the perspective of a seasoned coder with no prior electronics experience.

From cartoon to interactive infographic –the sane way

Making cartoon representations (technically vector graphics) in Adobe Illustrator is very fun, whereas the very idea of making a cartoon representation via line plots with Excel, Matlab, R, Plotly etc. would make anyone insane even just thinking about it. Luckily Illustrator images can be coloured based on numerical data in an automated way... without being manually plotted in Excel. Here I discuss exporting the vector graphic and modifying it with D3.js in a Jupyter notebook.

Remote notebooks and Jupyter themes

Jupyter notebooks are great. PyCharm is great for writing a module, but Jupyter notebook let's you test snippets of code really easily. You can add a Julia kernel, run bash and JS snippets and add markdown notes. The even greater thing is that you can run them off remote machines. If you have too many notebooks on different machines it gets confusing, but luckily there is jupyter themes that let's you customise the colours. Here are the different colours.

XML to Pyrosetta: EvolutionaryDynamicsMover as an example

In the previous post I discuss the strategies to use a Pyrosetta class when the documentation lets you down. One topic discussed was the conversion of a Rosetta XML script to Pyrosetta. Here is an example, namely using the EvolutionaryDynamics mover as an example.

Pyrosetta scripting without a manual

I got recently asked how to figure out how to write a Pyrosetta script when there is no example. This is definitely the biggest weakness of Pyrosetta and Rosetta script, but it is not insurmountable. In fact, there is a wealth of information that is hidden that can be mined. Here is how and in the next post, I give an example.

The Freedom unit for molar energy: the foot-pound-force per pound-mole

In computational biochemistry the most commonly used unit is molar energy. The SI unit is kJ/mol (kilojoule per mole), but kcal/mol is also as frequently used —Google enumerates 5.3e6 and 3.8e6 pages for them respectively. Different programs use one or the other, GROMACS uses kJ/mol, while Rosetta uses kcal/mol. They differ by a factor of about 4, the latter has the advantage that 1 kcal/mol is the strength of a hydrogen bond and k_BT/N_A is 0.6 kcal/mol (25°C) or 1. kcal/mol (37°C), while the former being SI sounds more sciency ——and not in the overly obnoxious way as folk who use Kelvin for enzymology.

However, whereas it is not an SI unit, kcal/mol is still very metric and European, after all the unit calorie was introduced by a Frenchman. Therefore, a more American unit is clearly required. Hence the need for the foot–pound-force per pound-mole.

Rosetta/Pyrosetta on a cluster or in the cloud

Due to licensing Rosetta and Pyrosetta cannot be installed via apt-get/pip but has to be downloaded from the Rosetta Commons website. This makes things harder if you are in a colabs notebook, ssh'ed into a machine or running off a remote jupyter notebook. Luckily it actually is straightforward.