X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=check%2Fcheck_numeric.cpp;h=47533029adef33bdeb12c55f9a64301a32b5b742;hp=ae15454566d77c9c855b92b87e01f273501b0275;hb=1d07d8ac9fb47c51aa19a84df6c8c5fee5dd5105;hpb=05c47b615d0d309d4868c688cd26f68376fa4277

diff --git a/check/check_numeric.cpp b/check/check_numeric.cpp
index ae154545..47533029 100644
--- a/check/check_numeric.cpp
+++ b/check/check_numeric.cpp
@@ -4,7 +4,7 @@
  *  tests on these numbers like is_integer() etc... */
 
 /*
- *  GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2003 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
@@ -66,22 +66,32 @@ static unsigned check_numeric2(void)
 			numeric nm(1,j);
 			nm += numeric(int(20.0*rand()/(RAND_MAX+1.0))-10);
 			// ...a numerator...
-			do { i_num = rand(); } while (i_num == 0);
+			do {
+				i_num = rand();
+			} while (i_num<=0);
 			numeric num(i_num);
 			// ...and a denominator.
-			do { i_den = (rand())/100; } while (i_den == 0);
+			do {
+				i_den = (rand())/100;
+			} while (i_den<=0);
 			numeric den(i_den);
 			// construct the radicals:
 			ex radical = pow(ex(num)/ex(den),ex(nm));
 			numeric floating = pow(num/den,nm);
 			// test the result:
 			if (is_a<numeric>(radical)) {
-				clog << "(" << num << "/" << den << ")^(" << nm
-				     << ") should have been a product, instead it's "
-				     << radical << endl;
-				errorflag = true;
+				// This is very improbable with decent random numbers but it
+				// still can happen, so we better check if it is correct:
+				if (pow(radical,inverse(nm))==num/den) {
+					// Aha! We drew some lucky numbers. Nothing to see here...
+				} else {
+					clog << "(" << num << "/" << den << ")^(" << nm
+						 << ") should have been a product, instead it's "
+						 << radical << endl;
+					errorflag = true;
+				}
 			}
-			numeric ratio = ex_to<numeric>(abs(evalf(radical)))/floating;
+			numeric ratio = abs(ex_to<numeric>(evalf(radical))/floating);
 			if (ratio>1.0001 && ratio<0.9999) {
 				clog << "(" << num << "/" << den << ")^(" << nm
 				     << ") erroneously evaluated to " << radical;