From: Chris Dams <Chris.Dams@mi.infn.it>
Date: Mon, 11 Dec 2006 18:51:37 +0000 (+0000)
Subject: Make eval do evalf if arguments of gamma or beta are floats.
X-Git-Tag: release_1-4-0~45
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=d9eaa10644d2f0d000b8cbae47d8544fcf646f91

Make eval do evalf if arguments of gamma or beta are floats.
---

diff --git a/ginac/inifcns_gamma.cpp b/ginac/inifcns_gamma.cpp
index c9adc199..2770193f 100644
--- a/ginac/inifcns_gamma.cpp
+++ b/ginac/inifcns_gamma.cpp
@@ -54,8 +54,7 @@ static ex lgamma_evalf(const ex & x)
 
 
 /** Evaluation of lgamma(x), the natural logarithm of the Gamma function.
- *  Knows about integer arguments and that's it.  Somebody ought to provide
- *  some good numerical evaluation some day...
+ *  Handles integer arguments as a special case.
  *
  *  @exception GiNaC::pole_error("lgamma_eval(): logarithmic pole",0) */
 static ex lgamma_eval(const ex & x)
@@ -69,7 +68,8 @@ static ex lgamma_eval(const ex & x)
 			else
 				throw (pole_error("lgamma_eval(): logarithmic pole",0));
 		}
-		//  lgamma_evalf should be called here once it becomes available
+		if (!ex_to<numeric>(x).is_rational())
+			return lgamma(ex_to<numeric>(x));
 	}
 	
 	return lgamma(x).hold();
@@ -165,7 +165,8 @@ static ex tgamma_eval(const ex & x)
 				return (pow(*_num_2_p, n).div(doublefactorial(n.mul(*_num2_p).sub(*_num1_p))))*sqrt(Pi);
 			}
 		}
-		//  tgamma_evalf should be called here once it becomes available
+		if (!ex_to<numeric>(x).is_rational())
+			return tgamma(ex_to<numeric>(x));
 	}
 	
 	return tgamma(x).hold();
@@ -262,7 +263,8 @@ static ex beta_eval(const ex & x, const ex & y)
 		    (nx+ny).is_integer() &&
 		   !(nx+ny).is_positive())
 			 return _ex0;
-		// beta_evalf should be called here once it becomes available
+		if (!ex_to<numeric>(x).is_rational() || !ex_to<numeric>(x).is_rational())
+			return evalf(beta(x, y).hold());
 	}
 	
 	return beta(x,y).hold();