Message-ID: <20061129153309.GA6836@pu100877.student.princeton.edu>
Date: 2006-11-29T15:33:09Z
From: Tamas K Papp
Subject: Matrix*vector: coercing sparse to dense matrix for arithmetic
Hi,
I have a sparse Matrix (kronecker product of spline design matrices),
and I need to multiply each row by a number to get another matrix. If
the matrix is A and the numbers are stored in a vector k, with plain
vanilla matrices I would do
A*k
But when using the Matrix package (class of A is "dgCMatrix"), I get
the warning "coercing sparse to dense matrix for arithmetic". The
error message is perfectly reasonable, I am looking for a way to do it
right (keeping operations in the realm of sparse matrices). Any help
would be appreciated.
Thanks,
Tamas