id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
3533	Parameter range not checked in Incomplete Beta Function	Sylvain Jasson <jasson@…>	John Maddock	"The incomplete beta function is defined for a > 0, b > 0 and 0 <= x <= 1. 

A call to boost::math::ibeta(0,1,0.5) should raise an std::domain_error under default policy.  
The domain error on a (first parameter) is not detected.   

Here is some very simple code :
#include <iterator>
#include <algorithm>
#include ""boost/math/special_functions/beta.hpp""
#include ""boost/math/special_functions/gamma.hpp""
#include ""boost/math/special_functions/log1p.hpp""

int main()
{
  double df1,df2;
  double x;
  double ret_val;
  
  df1=0.0;
  df2=1;
  x=0.5;

  ret_val=boost::math::ibeta(df1,df2,x);

  std::cout<<"" df1 = ""<<df1<<"" df2= ""<<df2<<"" x= ""<< x <<"" I_x(df1,df2)= ""<<ret_val<<std::endl;
}
 

and the output :

df1 = 0 df2= 1 x= 0.5 I_x(df1,df2)= 1

(using g++ 4.3.2)
"	Bugs	closed	Boost 1.41.0	math	Boost 1.40.0	Problem	fixed