Initial commit

2016-02-03 18:52:05 +00:00
commit d40505e161
507 changed files with 91383 additions and 0 deletions
@@ -0,0 +1,28 @@
+      SUBROUTINE rkdumb(vstart,nvar,x1,x2,nstep,derivs)
+      INTEGER nstep,nvar,NMAX,NSTPMX
+      PARAMETER (NMAX=50,NSTPMX=200)
+      REAL x1,x2,vstart(nvar),xx(NSTPMX),y(NMAX,NSTPMX)
+      EXTERNAL derivs
+      COMMON /path/ xx,y
+CU    USES rk4
+      INTEGER i,k
+      REAL h,x,dv(NMAX),v(NMAX)
+      do 11 i=1,nvar
+        v(i)=vstart(i)
+        y(i,1)=v(i)
+11    continue
+      xx(1)=x1
+      x=x1
+      h=(x2-x1)/nstep
+      do 13 k=1,nstep
+        call derivs(x,v,dv)
+        call rk4(v,dv,nvar,x,h,v,derivs)
+        if(x+h.eq.x)pause 'stepsize not significant in rkdumb'
+        x=x+h
+        xx(k+1)=x
+        do 12 i=1,nvar
+          y(i,k+1)=v(i)
+12      continue
+13    continue
+      return
+      END