i want to calculate gldm features .How do i do that?

i have the code to calculate gldm pdfs but i have to calculate features from it like contrast, Angular second moment entropy,mean and inverse difference moments.this is link to gldm code https://in.mathworks.com/matlabcentral/fileexchange/25057-texture-feature-extraction-gldm. the resultant pdf1 are column matrix i dont knw how to calculate its features ...please help