4.11 psb_normi — Infinity Norm of Sparse Matrix

This function computes the infinity-norm of a matrix A:

nrmi ←  ∥A∥∞

where:

A
represents the global matrix A




A Function


Short Precision Real psb_spnrmi
Long Precision Real psb_spnrmi
Short Precision Complexpsb_spnrmi
Long Precision Complex psb_spnrmi



Table 11: Data types

psb_spnrmi(A, desc_a, info)  
psb_normi(A, desc_a, info)

Type:
Synchronous.
On Entry
a
the local portion of the global sparse matrix A.
Scope: local
Type: required
Intent: in.
Specified as: an object of type psb_Tspmat_type.
desc_a
contains data structures for communications.
Scope: local
Type: required
Intent: in.
Specified as: an object of type psb_desc_type.
On Return
Function value
is the infinity-norm of sparse submatrix A.
Scope: global
Specified as: a long precision real number.
info
Error code.
Scope: local
Type: required
Intent: out.
An integer value; 0 means no error has been detected.