### Matrix-vector product for symmetric tridiagonal matrices?

Posted:

**Tue May 03, 2005 6:38 am**Hi!

I was wondering whether there is a LAPACK/BLAS routine for matrix-vector product where the matrix is a symmetric tridiagonal matrix? I was able to find an auxiliary LAPACK routine (xLAGTM) for a general tridiagonal matrix, but I would also like one for symmetric tridiagonal matrices. It's strange if there is no matrix-vector product for symmetric tridiagonal matrices, when the matrix-format is generally supported?

Thanks!

johnr

I was wondering whether there is a LAPACK/BLAS routine for matrix-vector product where the matrix is a symmetric tridiagonal matrix? I was able to find an auxiliary LAPACK routine (xLAGTM) for a general tridiagonal matrix, but I would also like one for symmetric tridiagonal matrices. It's strange if there is no matrix-vector product for symmetric tridiagonal matrices, when the matrix-format is generally supported?

Thanks!

johnr