synced to 1.2 (typos, better ncmul::degree() and ::coeff())

[ginac.git] / check / exam_misc.cpp

diff --git a/check/exam_misc.cpp b/check/exam_misc.cpp
index d703a93ada5eca54a7fe1966544d1ae80d2276f3..6866f44af1e38cce27a5a33440a6d12f42c93f38 100644 (file)
--- a/check/exam_misc.cpp
+++ b/check/exam_misc.cpp
@@ -3,7 +3,7 @@
  */
 
 /*
- *  GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2004 Johannes Gutenberg University Mainz, Germany
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -24,7 +24,7 @@
 #include "exams.h"
 
 #define VECSIZE 30
-static unsigned exam_expand_subs(void)
+static unsigned exam_expand_subs()
 {
        unsigned result = 0;
        symbol a[VECSIZE];
@@ -51,7 +51,7 @@ static unsigned exam_expand_subs(void)
  *  2)  expand e
  *  3)  substitute a0 by -a1 in e
  *  after which e should return 0 (without expanding). */
-static unsigned exam_expand_subs2(void)
+static unsigned exam_expand_subs2()
 {
        unsigned result = 0;
        symbol a("a"), b("b");
@@ -69,7 +69,7 @@ static unsigned exam_expand_subs2(void)
        return result;
 }
 
-static unsigned exam_expand_power(void)
+static unsigned exam_expand_power()
 {
        unsigned result = 0;
        symbol x("x"), a("a"), b("b");
@@ -86,7 +86,7 @@ static unsigned exam_expand_power(void)
        return result;
 }
 
-static unsigned exam_sqrfree(void)
+static unsigned exam_sqrfree()
 {
        unsigned result = 0;
        symbol x("x"), y("y");
@@ -133,7 +133,7 @@ static unsigned exam_sqrfree(void)
  * When somebody screws up the operators this routine will most probably fail
  * to compile.  Unfortunately we can only test the stuff that is allowed, not
  * what is forbidden (e.g. e1+e2 = 42) since that must not compile.  :-(   */
-static unsigned exam_operator_semantics(void)
+static unsigned exam_operator_semantics()
 {
        unsigned result = 0;
        ex e1, e2;
@@ -199,7 +199,72 @@ static unsigned exam_operator_semantics(void)
        return result;
 }
 
-unsigned exam_misc(void)
+/* This checks whether subs() works as intended in some special cases. */
+static unsigned exam_subs()
+{
+       unsigned result = 0;
+       symbol x("x");
+       ex e1, e2;
+
+       // This used to fail in GiNaC 1.0.5 because it first substituted
+       // x+1 -> (x-1)+1 -> x, and then substituted again x -> x-1, giving
+       // the wrong result
+       e1 = x+1;
+       e2 = e1.subs(x == x-1);
+       if (!e2.is_equal(x)) {
+               clog << "(x+1).subs(x==x-1) erroneously returned " << e2 << " instead of x" << endl;
+               ++result;
+       }
+
+       e1 = sin(1+sin(x));
+       e2 = e1.subs(sin(wild()) == cos(wild()));
+       if (!e2.is_equal(cos(1+cos(x)))) {
+               clog << "sin(1+sin(x)).subs(sin($1)==cos($1)) erroneously returned " << e2 << " instead of cos(1+cos(x))" << endl;
+               ++result;
+       }
+
+       return result;
+}
+
+/* Joris van der Hoeven (he of TeXmacs fame) is a funny guy.  He has his own
+ * ideas what a symbolic system should do.  Let's make sure we won't disappoint
+ * him some day.  Incidentally, this seems to always have worked. */
+static unsigned exam_joris()
+{
+       unsigned result = 0;
+       symbol x("x");
+
+       ex e = expand(pow(x, x-1) * x);
+       if (e != pow(x, x)) {
+               clog << "x^(x-1)*x did not expand to x^x.  Please call Joris!" << endl;
+               ++result;
+       }
+
+       return result;
+}
+
+/* Test Chris Dams' algebraic substitutions. */
+static unsigned exam_subs_algebraic()
+{
+       unsigned result = 0;
+       symbol x("x"), y("y");
+
+       ex e = ex(x*x*x*y*y).subs(x*y==2, subs_options::subs_algebraic);
+       if (e != 4*x) {
+               clog << "(x^3*y^2).subs(x*y==2,subs_options::subs_algebraic) erroneously returned " << e << endl;
+               ++result;
+       }
+
+       e = ex(x*x*x*x*x).subs(x*x==y, subs_options::subs_algebraic);
+       if (e != y*y*x) {
+               clog << "x^5.subs(x^2==y,subs_options::subs_algebraic) erroneously returned " << e << endl;
+               ++result;
+       }
+       
+       return result;
+}
+
+unsigned exam_misc()
 {
        unsigned result = 0;
        
@@ -211,6 +276,9 @@ unsigned exam_misc(void)
        result += exam_expand_power(); cout << '.' << flush;
        result += exam_sqrfree(); cout << '.' << flush;
        result += exam_operator_semantics(); cout << '.' << flush;
+       result += exam_subs(); cout << '.' << flush;
+       result += exam_joris(); cout << '.' << flush;
+       result += exam_subs_algebraic(); cout << '.' << flush;
        
        if (!result) {
                cout << " passed " << endl;