I have a question about the histogram plot in the statistic section. I was wondering about the frequency (y-scale) in my plots. To my mind it cannot be the relative frequency (sum>1) but it also cannot be the absolute amount of values as the sum is bigger than the amount of vectors in the analyzed field. Even if I try to rebuild the plot by creating a histogram in MatLab with identical bins I will get a different histogram.
Can anyone (maybe William) give me an insight in the construction/math of this histogram plot in the statistic section?
this is the code used in PIVlab_GUI.m (example for u velocity component):
nrofbins=100; %default bin amount
u=reshape(u,size(u,1)*size(u,2),1); %make a vector out of the matrix
[n xout]=hist(u*caluv-retr('subtr_u'),nrofbins); %create histogram data, the old way
h2=bar(xout,n); %plot histogram
The height of each bar indicates the number of elements in the bin.