User`s manual

Examples of Fortran MEX-Files
3-31
C
C This is a MEX-file for MATLAB.
C Copyright (c) 1984-2000 The MathWorks, Inc.
C
C===============================================================
C Load sparse data subroutine.
function loadsparse(a,b,ir,jc,m,n,nzmax)
integer nzmax, m, n
integer ir(*), jc(*)
real*8 a(*), b(*)
integer i, j, k
C Copy nonzeros.
k = 1
do 100 j=1,n
C NOTE: Sparse indexing is zero based.
jc(j) = k-1
do 200 i=1,m
if (a((j-1)*m+i).ne. 0.0) then
if (k .gt. nzmax) then
jc(n+1) = nzmax
loadsparse = 1
goto 300
endif
b(k) = a((j-1)*m+i)
C NOTE: Sparse indexing is zero based.
ir(k) = i-1
k = k+1
endif
200 continue
100 continue
C NOTE: Sparse indexing is zero based.
jc(n+1) = k-1
loadsparse = 0
300 return
end