From 40e5a5811c6ffce9b0974e93cdd927cbcf60c157 Mon Sep 17 00:00:00 2001 From: Joe Hunkeler Date: Tue, 11 Aug 2015 16:51:37 -0400 Subject: Repatch (from linux) of OSX IRAF --- noao/digiphot/photcal/mkobsfile/dinvers.f | 53 +++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 noao/digiphot/photcal/mkobsfile/dinvers.f (limited to 'noao/digiphot/photcal/mkobsfile/dinvers.f') diff --git a/noao/digiphot/photcal/mkobsfile/dinvers.f b/noao/digiphot/photcal/mkobsfile/dinvers.f new file mode 100644 index 00000000..5b1d8a5f --- /dev/null +++ b/noao/digiphot/photcal/mkobsfile/dinvers.f @@ -0,0 +1,53 @@ +c +c subroutine dinver (a, max, n, iflag) +c +c Arguments +c +c a (input/output) is a square matrix of dimension N. The inverse +c of the input matrix A is returned in A. +c +c max (input) is the size assigned to the matrix A in the calling +c routine. It's needed for the dimension statement below. +c +c iflag (output) is an error flag. iflag = 1 if the matrix could not +c be inverted; iflag = 0 if it could. +c + subroutine dinver (a, max, n, iflag) +c + implicit none + integer max, n, iflag + double precision a(max,max) + integer i, j, k +c + iflag = 0 + i = 1 + 300 if (a(i,i) .eq. 0.0d0) go to 9100 + a(i,i) = 1.0e0 / a(i,i) + j = 1 + 301 if (j .eq. i) go to 304 + a(j,i) = -a(j,i) * a(i,i) + k = 1 + 302 if (k .eq. i) go to 303 + a(j,k) = a(j,k) + a(j,i) * a(i,k) + 303 if (k .eq. n) go to 304 + k = k + 1 + go to 302 + 304 if (j .eq. n) go to 305 + j = j + 1 + go to 301 + 305 k = 1 + 306 if (k .eq. i) go to 307 + a(i,k) = a(i,k) * a(i,i) + 307 if (k .eq. n) go to 308 + k = k + 1 + go to 306 + 308 if (i .eq. n) return + i = i+1 + go to 300 +c +c Error: zero on the diagonal. +c + 9100 iflag = 1 + return +c + end -- cgit