Mastering Numerical Computing with NumPy

Computing histograms

A histogram is a visual representation of the distribution of numerical data. Karl Pearson first introduced this concept more than a century ago. A histogram is a kind of bar chart that is used for continuous data, while a bar chart visually represents categorical variables. As a first step, you need to divide your entire range of values into a series of intervals (bins). Each bin has to be adjacent and none of them can overlap. In general, bin sizes are equal, and the rule of thumb for the number of bins to include is 5–20. This means that if you have more than 20 bins, your graph will be hard to read. On the contrary, if you have fewer than 5 bins, then your graph will give very little insight into the distribution ...