DOUBLE PRECISION FUNCTION D1NRM(NR,N,M,A) C C *****PARAMETERS: INTEGER NR,N,M DOUBLE PRECISION A(NR,M) C C *****LOCAL VARIABLES: INTEGER I,J DOUBLE PRECISION TEMP C C *****FORTRAN FUNCTIONS: DOUBLE PRECISION DABS, DMAX1 C C *****SUBROUTINES CALLED: C NONE C C ----------------------------------------------------------------- C C *****PURPOSE: C GIVEN AN N BY M MATRIX A, THIS FUNCTION COMPUTES ITS 1-NORM. C C *****PARAMETER DESCRIPTION: C C ON INPUT: C C NR INTEGER C ROW DIMENSION OF THE ARRAY CONTAINING THE MATRIX A AS C DECLARED IN THE MAIN CALLING PROGRAM DIMENSION C STATEMENT; C C N INTEGER C NUMBER OF ROWS OF THE MATRIX A; C C M INTEGER C NUMBER OF COLUMNS OF THE MATRIX A; C C A REAL(NR,M) C MATRIX WHOSE 1-NORM IS TO BE COMPUTED. C C ON OUTPUT: C C D1NRM REAL C CONTAINS THE 1-NORM OF THE MATRIX A. C C *****ALGORITHM NOTES: C NONE. C C *****HISTORY: C THIS SUBROUTINE WAS WRITTEN BY W.F. ARNOLD, NAVAL WEAPONS CENTER, C CODE 35104, CHINA LAKE, CA 93555, AS PART OF THE SOFTWARE PACKAGE C RICPACK, SEPTEMBER 1983. C C ------------------------------------------------------------------ C D1NRM = 0.0D0 DO 20 I=1,M TEMP = 0.0D0 DO 10 J=1,N TEMP = TEMP + DABS(A(J,I)) 10 CONTINUE D1NRM = DMAX1(D1NRM,TEMP) 20 CONTINUE RETURN C C LAST LINE OF D1NRM C END