SuperLU  5.0
Functions
slangs.c File Reference

Returns the value of the one norm. More...

#include <math.h>
#include "slu_sdefs.h"
Include dependency graph for slangs.c:

Functions

float slangs (char *norm, SuperMatrix *A)
 

Detailed Description

– SuperLU routine (version 2.0) –
Univ. of California Berkeley, Xerox Palo Alto Research Center,
and Lawrence Berkeley National Lab.
November 15, 1997
Modified from lapack routine SLANGE 

Function Documentation

float slangs ( char *  norm,
SuperMatrix A 
)

Purpose

  SLANGS returns the value of the one norm, or the Frobenius norm, or 
  the infinity norm, or the element of largest absolute value of a 
  real matrix A.

Description

  SLANGE returns the value
     SLANGE = ( max(abs(A(i,j))), NORM = 'M' or 'm'   
              (   
              ( norm1(A),         NORM = '1', 'O' or 'o'   
              (   
              ( normI(A),         NORM = 'I' or 'i'   
              (   
              ( normF(A),         NORM = 'F', 'f', 'E' or 'e'
  where  norm1  denotes the  one norm of a matrix (maximum column sum), 
  normI  denotes the  infinity norm  of a matrix  (maximum row sum) and 
  normF  denotes the  Frobenius norm of a matrix (square root of sum of 
  squares).  Note that  max(abs(A(i,j)))  is not a  matrix norm.

Arguments

  NORM    (input) CHARACTER*1   
          Specifies the value to be returned in SLANGE as described above.   
  A       (input) SuperMatrix*
          The M by N sparse matrix A.