explain figure(1) subplot(2,1,1); histogram(ppamp, 100) subplot(2,1,2); histogram(ppamp2,100) in matlab

The code figure(1) creates a new figure window, with a Figure handle number of 1.

The subplot(2,1,1) command creates an axis in the current figure window, with a 2 x 1 grid of subplots, and selects the first subplot (i.e. the top subplot). The command subplot(2,1,2) then selects the second subplot (i.e. the bottom subplot).

The histogram function is then used to plot a histogram of the data. The data for the top subplot is ppamp and the data for the bottom subplot is ppamp2. The 100 argument specifies the number of bins used for the histogram.

So overall, the code creates a figure window with two histograms. The top histogram shows the data in ppamp and the bottom histogram shows the data in ppamp2.