[Maxima-commits] CVS: maxima/share/algebra gcdex.mac,1.2,1.3

[Andrej V. <an...@us...>]

Update of /cvsroot/maxima/maxima/share/algebra
In directory sc8-pr-cvs16.sourceforge.net:/tmp/cvs-serv29476

Modified Files:
	gcdex.mac 
Log Message:
Extended gcdex to work with integers.


Index: gcdex.mac
===================================================================
RCS file: /cvsroot/maxima/maxima/share/algebra/gcdex.mac,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -d -r1.2 -r1.3
--- gcdex.mac	5 Jun 2001 09:05:14 -0000	1.2
+++ gcdex.mac	26 Dec 2007 10:13:23 -0000	1.3
@@ -17,36 +17,42 @@
 		  remainder(g,ans[3],v)]);  
     
 */      
-gcdex(f,g,[var]):=block([q0,q1,ok:true,lis1,lis2,lis3,q,tem,       result],
+gcdex(f,g,[var]):=block([q0,q1,ok:true,lis1,lis2,lis3,q,tem,result],
+  if integerp(f) and integerp(g) then return( igcdex(f, g) ),
   if (var = [])  then var:listofvars([f,g]),
   if not (length(var) = 1) 
-       then (if (f=0 and g=0) then return([0,0,0]),
-	     error("Specify one main variable or give univariate polynomials")
-	    ),
+  then (if (f=0 and g=0) then return([0,0,0]),
+    error("Specify one main variable or give univariate polynomials")
+    ),
   var:var[1],
   f:rat(f),g:rat(g),		    
   q0:divide(f,g,var),   /* divide(f,g) ==> [q:quotient(f,g),remainder:f-g*q] */
-	      /* if f/g is 0 then we reverse them */
+  /* if f/g is 0 then we reverse them */
   if (q0[1]=0) then
-    /* the deg f < deg g */
-    (lis2:gcdex(g,f,var),return([lis2[2],lis2[1],lis2[3]])),
+  /* the deg f < deg g */
+  (lis2:gcdex(g,f,var),return([lis2[2],lis2[1],lis2[3]])),
   if (q0[2]=0) then lis2:[0,1,g]
+  else (
+    q1:divide(g,q0[2],var), 	
+    lis1:[1,-q0[1],q0[2]],			
+    if (q1[2]=0) then lis2:lis1
     else (
-	 q1:divide(g,q0[2],var), 	
-	  lis1:[1,-q0[1],q0[2]],			
-	  if (q1[2]=0) then lis2:lis1
-	    else (
       /* lisi are always perpendicular to [f,g,-1] */
-		 lis2:[-q1[1],1+q0[1]*q1[1], q1[2]],
-		  while(ok) do 
-		    ( q:divide(lis1[3],lis2[3],var),
-		     lis3:lis1-lis2*q[1],
-		     if(lis3[3] = 0) then ok:false
-				     else (lis1:lis2, 
-					   lis2:lis3/content(lis3[3],var)[1])
-		    ))),
-   if freeof(var,lis2[3]) then lis2/lis2[3] else lis2);
-     
-
-
+      lis2:[-q1[1],1+q0[1]*q1[1], q1[2]],
+      while(ok) do 
+      ( q:divide(lis1[3],lis2[3],var),
+        lis3:lis1-lis2*q[1],
+        if(lis3[3] = 0) then ok:false
+        else (lis1:lis2, 
+          lis2:lis3/content(lis3[3],var)[1])
+        ))),
+  if freeof(var,lis2[3]) then lis2/lis2[3] else lis2);
 
+igcdex(a,b) := block(
+  [x:0, lx:1, y:1, ly:0, q, r],
+  while b#0 do (
+    [q,r]:divide(a,b),
+    [a,b]:[b,r],
+    [x,lx]:[lx-q*x,x],
+    [y,ly]:[ly-q*y,y]),
+  [lx,ly,a])$