checks for all nonzero elements

checks for any nonzero elements

returns the number of missing values

returns the number of nonmissing values

returns the number of unique values

conditionally chooses and changes elements

returns the number of rows and columns of a matrix

finds indices for the nonzero elements of a matrix

finds the number of columns of a matrix

finds the size of an element

finds the number of rows of a matrix

determines the type of a matrix