next up previous contents
Next: psb_norm1 1-Norm Up: Computational routines Previous: psb_normi Infinity-Norm   Contents

psb_geamaxs -- Generalized Infinity Norm

This subroutine computes a series of infinity norms on the columns of a dense matrix $x$:

\begin{displaymath}res(i) \leftarrow \max_k \vert x(k,i)\vert \end{displaymath}

call psb_geamaxs(res, x, desc_a, info)


Table 5: Data types
$res$ $x$ Subroutine
Short Precision Real Short Precision Real psb_geamaxs
Long Precision Real Long Precision Real psb_geamaxs
Short Precision Real Short Precision Complex psb_geamaxs
Long Precision Real Long Precision Complex psb_geamaxs


Type:
Synchronous.
On Entry
x
the local portion of global dense matrix $x$.
Scope: local
Type: required
Intent: in.
Specified as: a rank one or two array or an object of type vdatapsb_T_vect_type containing numbers of type specified in Table 5.
desc_a
contains data structures for communications.
Scope: local
Type: required
Intent: in.
Specified as: an object of type descdatapsb_desc_type.
On Return
res
is the infinity norm of the columns of $x$.
Scope: global
Intent: out.
Specified as: a number or a rank-one array of long precision real numbers.
info
Error code.
Scope: local
Type: required
Intent: out.
An integer value; 0 means no error has been detected.


next up previous contents
Next: psb_norm1 1-Norm Up: Computational routines Previous: psb_normi Infinity-Norm   Contents