Specifying Number of Bins :: Creating Specialized Plots (Graphics)

Graphics

Specifying Number of Bins

hist and rose interpret their second argument in one of two ways -- as the locations on the axis or the number of bins. When the second argument is a vector x, it specifies the locations on the axis and distributes the elements in length(x) bins. When the second argument is a scalar x, hist and rose distribute the elements in x bins.

For example, compare the distribution of data created by two MATLAB functions that generate random numbers. The randn function generates normally distributed random numbers, whereas the rand function generates uniformly distributed random numbers.

yn = randn(10000,1);
yu = rand(10000,1);

The first histogram displays the data distribution resulting from the randn function. The locations on the x-axis and number of bins depend on the vector x.

x = min(yn):.2:max(yn);
subplot(1,2,1)
hist(yn,x)
title('Normally Distributed Random Numbers','FontSize',16)

The second histogram displays the data distribution resulting from the rand function and explicitly creates 25 bins along the x-axis.

subplot(1,2,2)
hist(yu,25)
title('Uniformly Distributed Random Numbers','FontSize',16)

Note You can change the aspect ratio of the histogram plots using the mouse to resize the figure window. However, before creating hardcopy output, set the figure's PaperPositionMode to auto to produce printed output that matches the display.

  set(gcf,'PaperPositionMode','auto')

Histograms in Polar Coordinates Discrete Data Graphs