Here is a list of some of my python coding projects.

• Fitting an ellipse. Suppose a rockets moves around the earth in a perfectly circular orbit. Suddenly the captain decides to hit the break for an infinitely short amount of time. The orbit should then become an ellipse. I once analyzed this behavior with the scipys numerical differential equation solver. The result was a set of points that, once plotted, appeared to by elliptical. To check whether this was indeed true, I developed this code.
• Weighted random shuffling This code helps to sample from a list of items, but such that the selection of items is not uniformly distributed, which you would get with random.sample, but in proportion to a given set of weigths $w$.

• Markov chains Generating Markov chains, and computing the stationary distribution, can be a bit painfull. With this code it is hopefully a bit simpler.

## Miscellaneous

• Memoization Examples Memoization is extremely useful when some computations involve recursions, such as in dynamic programming problems with finite horizon. Here I show two simple examples how to apply this programming concept in python.
• Parallel translations. Here you can find a about 100 stories in a dual language stories in Durch and English, and some of them are also translated to Spanish and Turkish. The stories start simple but become increasingly more difficult.