Just to add to @styfen.schaer 's answer…
By default the histogram created by
uq_histogram is already normalized though perhaps not normalized the way you want it. Specifically, the normalization is done such that the area under the histogram is equal to 1. Unless you don’t turn the normalization option off (via named argument
'Normalized'), the y-axis of the histogram produced by
uq_histogram is not frequency (i.e., not raw counts). If the area under the curve must be 1 (representing a PDF), then the values at the y-axis do not need to be less than 1.
As already pointed out by @styfen.schaer, the Matlab function
histogram does provide several other normalizations not available in
'pdf' normalization in
histogram is the same as the default normalization of
uq_histogram. Note that the
'probability' normalization simply normalizes the histogram with the total number of data points and the area under the histogram won’t be, in general, summed to 1.
I hope this clarifies a bit how