1 files changed, 48 insertions, 0 deletions
diff --git a/math/deboor/sbblok.f b/math/deboor/sbblok.f
new file mode 100644
index 00000000..8c4a77fb
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+++ b/math/deboor/sbblok.f
@@ -0,0 +1,48 @@
+      subroutine sbblok ( bloks, integs, nbloks, ipivot, b, x )
+calls subroutines  s u b f o r	and  s u b b a k .
+c
+c  supervises the solution (by forward and backward substitution) of
+c  the linear system  a*x = b  for x, with the plu factorization of  a
+c  already generated in  f c b l o k .	individual blocks of equations
+c  are solved via  s u b f o r	and  s u b b a k .
+c
+c parameters
+c    bloks, integs, nbloks, ipivot    are as on return from fcblok.
+c    b	     the right side, stored corresponding to the storage of
+c	     the equations. see comments in  s l v b l k  for details.
+c    x	     solution vector
+c
+      integer nbloks
+      integer integs(3,nbloks),ipivot(1), i,index,indexb,indexx,j,last,
+     *	      nbp1,ncol,nrow
+      real bloks(1),b(1),x(1)
+c
+c      forward substitution pass
+c
+      index = 1
+      indexb = 1
+      indexx = 1
+      do 20 i=1,nbloks
+	 nrow = integs(1,i)
+	 last = integs(3,i)
+	 call subfor(bloks(index),ipivot(indexb),nrow,last,b(indexb),
+     *		     x(indexx))
+	 index = nrow*integs(2,i) + index
+	 indexb = indexb + nrow
+   20	 indexx = indexx + last
+c
+c     back substitution pass
+c
+      nbp1 = nbloks + 1
+      do 30 j=1,nbloks
+	 i = nbp1 - j
+	 nrow = integs(1,i)
+	 ncol = integs(2,i)
+	 last = integs(3,i)
+	 index = index - nrow*ncol
+	 indexb = indexb - nrow
+	 indexx = indexx - last
+   30	 call subbak(bloks(index),ipivot(indexb),nrow,ncol,last,
+     *		     x(indexx))
+					return
+      end