Changeset 1297 for branches/f4grobner

Timestamp:

2015-06-11T20:46:28-07:00 (9 years ago)

Author:

Marek Rychlik

Message:

* empty log message *

File:

• branches/f4grobner/division.lisp (modified) (1 diff)

branches/f4grobner/division.lisp

@@ -243 +243 @@
   "Divide every polynomial in a list PLIST by its leading coefficient. "
   (mapcar #'(lambda (x) (poly-normalize ring x)) plist))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;
+;; The function GROBNER-CHECK is provided primarily for debugging purposes. To
+;; enable verification of grobner bases with BUCHBERGER-CRITERION, do
+;; (pushnew :grobner-check *features*) and compile/load this file.
+;; With this feature, the calculations will slow down CONSIDERABLY.
+;;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(defun grobner-test (ring g f)
+  "Test whether G is a Grobner basis and F is contained in G. Return T
+upon success and NIL otherwise."
+  (debug-cgb "~&GROBNER CHECK: ")
+  (let (($poly_grobner_debug nil)
+        (stat1 (buchberger-criterion ring g))
+        (stat2
+          (every #'poly-zerop
+                 (makelist (normal-form ring (copy-tree (elt f i)) g nil)
+                           (i 0 (1- (length f)))))))
+    (unless stat1 (error "~&Buchberger criterion failed."))
+    (unless stat2
+      (error "~&Original polys not in ideal spanned by Grobner.")))
+  (debug-cgb "~&GROBNER CHECK END")
+  t)