Measures the percentiles of the sample in X. Y = PRCTILE(X,P) Returns the value in the vector X that is greater than P percent of the values in X. For example, prctile(x,50) is the median of X. P may be either a scalar or a vector. For scalar P, Y is a row vector containing Pth percentile of each column of X. For vector P, the ith row of Y is the P(i) percentile of each column of X. Taken from the Matlab distribution.