[Maxima-commits] CVS: maxima/src factor.lisp,1.6,1.7 ratmac.lisp,1.5,1.6

[Raymond T. <rt...@us...>]

Update of /cvsroot/maxima/maxima/src
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv10975/src

Modified Files:
	factor.lisp ratmac.lisp 
Log Message:
src/factor.lisp:
o Change primcyclo to bind a gensym to *g* and give it a value.  This
  fixes the bug 1449163: ratsimp(exp(%pi*%i/9)/(x-2)^(1/7)) causes
  error.

src/ratmac.lisp:
o Add a historical comment on what pointergp does.


Index: factor.lisp
===================================================================
RCS file: /cvsroot/maxima/maxima/src/factor.lisp,v
retrieving revision 1.6
retrieving revision 1.7
diff -u -d -r1.6 -r1.7
--- factor.lisp	7 Nov 2005 17:37:11 -0000	1.6
+++ factor.lisp	17 Mar 2006 13:59:59 -0000	1.7
@@ -61,6 +61,7 @@
 (defun csqfrp ($factorflag)
   (null (zl-delete 1 (oddelm (cdr (cfactor $factorflag))))))
 
+#+nil
 (defun primcyclo (n &aux *g* (nl (cfactorw n)))
   (setq nl (loop for (c e) on nl by #'cddr
 		  nconc (*make-list e c)))
@@ -69,6 +70,16 @@
 	  ((eql 0 res) nil)
 	  (t (list 0 res)))))
 
+(defun primcyclo (n)
+  (let ((*g* (gensym "PRIMCYCLO-"))
+	(nl (loop for (c e) on (cfactorw n) by #'cddr
+	       nconc (*make-list e c))))
+    (setf (symbol-value *g*) 0)
+    (let ((res (cyclotomic (list n nl))))
+      (cond ((consp res) (p-terms res))
+	    ((eql 0 res) nil)
+	    (t (list 0 res))))))
+
 (defun factxn+-1 (p) 
   (let ((*g* (car p))
 	($factorflag t)) 
@@ -1417,4 +1428,4 @@
 
 ;;(DEFMVAR *ALPHA (CAR BIGPRIMES))
 
- 
\ No newline at end of file
+ 

Index: ratmac.lisp
===================================================================
RCS file: /cvsroot/maxima/maxima/src/ratmac.lisp,v
retrieving revision 1.5
retrieving revision 1.6
diff -u -d -r1.5 -r1.6
--- ratmac.lisp	7 Nov 2005 17:37:12 -0000	1.5
+++ ratmac.lisp	17 Mar 2006 13:59:59 -0000	1.6
@@ -58,8 +58,27 @@
 (defmacro valput (item val)
   `(setf (valget ,item) ,val))
 
+;; A historical note from Richard Fateman, on the maxima list,
+;; 2006/03/17:
+;;
+;; "The name pointerp comes from the original hack when we wanted a
+;; bunch of atoms that could be ordered fast, we just generated, say,
+;; 10 gensyms.  Then we sorted them by the addresses of the symbols in
+;; memory.  Then we associated them with x,y,z,....  This meant that
+;; pointergp was one or two instructions on a PDP-10, in assembler."
+;; 
+;; "That version of pointergp turned out to be more trouble than it was
+;; worth because we sometimes had to interpolate between two gensym
+;; "addresses" and to do that we had to kind of renumber too much of
+;; the universe.  Or maybe we just weren't clever enough to do it
+;; without introducing bugs."
+;;
+;; Richard Fateman also says pointergp needs to be fast because it's
+;; called a lot.  So if you get an error from pointergp, it's probably
+;; because someone forgot to initialize things correctly.
 (proclaim '(inline pointergp))
-(defun pointergp (a b) (f> (valget a) (valget b)))
+(defun pointergp (a b)
+  (f> (valget a) (valget b)))
 
 ;;(macro ALGV (L) `(AND $ALGEBRAIC (GET ,(CADR L) 'TELLRAT)))
 (defmacro algv (v)