scaleMargins: Scale Rows and/or Columns of a Matrix (wordspace)
Description
This function provides a fast and memory-efficient way to scale the rows and/or columns
of a dense or sparse matrix. Each row is multiplied with the corresponding element of
the vector rows, each column with the corresponding element of the vector cols.
If M is not in canonical format (dense numeric matrix or sparse matrix of class dgCMatrix),
it will automatically be converted. In this case, the precise behaviour of duplicate=FALSE is undefined.
duplicate=FALSE is intended for internal use only.