pdf Output the pdf of the random variable evaluated at the points specified
 
  pdf = RV.pdf(X) returns  the pdf of the prtRv
  object evaluated at X. X must be an N x nDims matrix, where
  N is the number of locations to evaluate the pdf, and nDims
  is the same as the number of dimensions, nDimensions, of the
  prtRv object RV.