Distribution plot of an array

Question

I have a `numpy` array containing float values in [-10..10]. I would like to plot a distribution-graph of the values, like this (here it is done for a binomial random variable) : For example I would like bars counting the number of elements in each interval [-10, -9.5], [-9.5, -9], ..., [9.5, 10]. How to prepare such a distribution plot with Python?

Accepted Answer

Indeed matplotlib, more precisely you'll find samples of code corresponding to what you are after at: http://matplotlib.org/examples/pylab_examples/histogram_demo_extended.html

```
import numpy as np
import matplotlib.pyplot as plt
mu, sigma = 200, 25
x = mu + sigma*np.random.randn(10000)
n, bins, patches = plt.hist(x)
plt.show()
```

`n` contains the number of points in each bin and `bins` the cut off values which are in my example generated automatically. You can of course play with `plt.hist`'s options to obtain the graph that you wish.

In your case, just replace `x` by your array, and play with the `bins` option for cut off values e.g.:

```
plt.hist(x, bins = [-10, -9.5, -9])
```

You can also simlply pass a scalar `n` to `bins` in which case `plt.hist` will determine cut off values to display a nice graph with `n` bins.

Distribution plot of an array

Solution

Problem