git-svn-id: file:///export/data/bremner/svn/trunk/inetools@5465 09fa754a-f411-0410-976a-da6bfa213b30

1 files changed, 139 insertions, 0 deletions

diff --git a/rat2int.c b/rat2int.c
new file mode 100644
index 0000000..24c7ade
--- /dev/null
+++ b/rat2int.c
@@ -0,0 +1,139 @@
+/*
+ * Reads a polyhedron file on stdin with rationals and outputs an equivalent 
+ * system with integer  coefficents.
+ * 
+ * David Bremner. bremner@unb.ca
+ *
+ */
+static char rcsid[]="$Id: rat2int.c 2055 2006-04-03 19:41:14Z bremner $";
+#include <stdlib.h>
+#include <stdio.h>
+
+#ifndef LRSMP
+#error This file only compiles with LRSMP
+#endif
+
+#include "lrsmp.h"
+#include "rat2int.h"
+
+static   long int  m,n,type;
+#define MP_DIGITS 1000L
+
+static void lcm3(lrs_mp a,lrs_mp b,lrs_mp c);
+
+
+main(int argc, char **argv)
+{
+
+
+  int i,j;
+  lrs_mp l,g,scratch;
+  char *type;
+  lrs_mp *D, *N;
+  char *ok[]={ "integer", "rational"};
+  process_args(argc,argv,DOCSTRING);
+  lrs_mp_init (MP_DIGITS,stdin,stdout);   
+  scan_for_begin(&m,&n,&type);
+
+  check_type(type, ok , 2);
+
+  printf("%d %d integer\n",m,n);
+  D=calloc(n,sizeof(lrs_mp));
+  N=calloc(n,sizeof(lrs_mp));
+  
+  for (i=0;i<m;i++)    {
+  
+      for (j=0; j<n; j++){
+	readrat(N[j],D[j]);
+      }
+
+      lcm3(D[0],D[1],l);
+      
+      for(j=2;j<n;j++){
+	lcm3(l,D[j],l);
+      }
+      
+      mul_row(N,D,l,0);
+
+      /* reinitialize gcd */
+      copy(g,N[0]);
+      copy(scratch,N[1]);
+      gcd(g,scratch);
+
+      for (j=2; j<n ; j++){
+      	copy(scratch,N[j]);
+	gcd(g,scratch);
+      }
+
+      if (negative(g)) 
+	storesign(g,POS);
+      
+      div_row(N,D,g,0);
+
+      for (j=0; j< n; j++){
+	pmp("",N[j]);
+      }
+      fputs("\n",stdout);
+  }
+  
+  printf("end\n");
+
+}
+
+/* c<- lcm(a,b) */
+
+static void lcm3(lrs_mp a,lrs_mp b,lrs_mp c)
+{
+  lrs_mp gc,ab,scratch;
+  
+  copy(gc,a);
+  copy(scratch,b);
+  gcd(gc,scratch);
+  
+
+  mulint(a,b,ab);
+    
+  divint(ab,gc,c);
+    
+}
+
+
+mul_row(N,D,l,offset)
+     lrs_mp *N,*D;
+     lrs_mp l;
+     int offset;
+{
+    lrs_mp  factor,scratch;
+  int j;
+
+  for  (j=offset;j<n;  j++) {
+
+    /* 
+     * Now multiply each numerator n_i by lcm/d_i.
+     * Implicitly, each denominator is now lcm
+     */
+
+    copy(scratch,l);
+    divint(scratch,D[j],factor);
+    mulint(N[j],factor,N[j]);
+  }
+
+}      
+
+div_row(N,D,g,offset)
+     lrs_mp *N,*D;
+     lrs_mp g;
+     int offset;
+{
+  lrs_mp  scratch;
+  int j;
+
+  for  (j=0;j<n;  j++)
+    {
+      copy(scratch,N[j]);
+	
+      divint(scratch,g,N[j]);
+    }
+
+}
+