1 files changed, 28 insertions, 0 deletions
diff --git a/CarpetExtra/IDHydroToy/src/gser.f77 b/CarpetExtra/IDHydroToy/src/gser.f77
new file mode 100644
index 000000000..fad2be01f
--- /dev/null
+++ b/CarpetExtra/IDHydroToy/src/gser.f77
@@ -0,0 +1,28 @@
+      SUBROUTINE gser(gamser,a,x,gln)
+      implicit none
+      INTEGER ITMAX
+      REAL*8 a,gamser,gln,x,EPS
+      PARAMETER (ITMAX=100,EPS=3.d-7)
+CU    USES gammln
+      INTEGER n
+      REAL*8 ap,del,sum,gammln
+      gln=gammln(a)
+      if(x.le.0)then
+        if(x.lt.0)pause 'x < 0 in gser'
+        gamser=0
+        return
+      endif
+      ap=a
+      sum=1/a
+      del=sum
+      do 11 n=1,ITMAX
+        ap=ap+1
+        del=del*x/ap
+        sum=sum+del
+        if(abs(del).lt.abs(sum)*EPS)goto 1
+11    continue
+      pause 'a too large, ITMAX too small in gser'
+1     gamser=sum*exp(-x+a*log(x)-gln)
+      return
+      END
+C  (C) Copr. 1986-92 Numerical Recipes Software t4.