/** @file inifcns_gamma.cpp
*
- * Implementation of Gamma function and some related stuff.
- *
+ * Implementation of Gamma function and some related stuff. */
+
+/*
* GiNaC Copyright (C) 1999 Johannes Gutenberg University Mainz, Germany
*
* This program is free software; you can redistribute it and/or modify
#include <vector>
#include <stdexcept>
-#include "ginac.h"
+#include "inifcns.h"
+#include "ex.h"
+#include "constant.h"
+#include "numeric.h"
+#include "power.h"
+#include "symbol.h"
+
+namespace GiNaC {
//////////
// gamma function
* evaluation some day...
*
* @exception fail_numeric("complex_infinity") or something similar... */
-ex gamma_eval(ex const & x)
+static ex gamma_eval(ex const & x)
{
if ( x.info(info_flags::numeric) ) {
numeric n = ex_to_numeric(x).sub(numHALF());
numeric coefficient = doublefactorial(n.mul(numTWO()).sub(numONE()));
coefficient = coefficient.div(numTWO().power(n));
- return mul(coefficient,power(Pi,numHALF()));
+ return coefficient * power(Pi,numHALF());
} else {
// trap negative x=(-n+1/2)
// gamma(-n+1/2) -> Pi^(1/2)*(-2)^n/(1*3*..*(2*n-1))
numeric n = abs(ex_to_numeric(x).sub(numHALF()));
numeric coefficient = numeric(-2).power(n);
coefficient = coefficient.div(doublefactorial(n.mul(numTWO()).sub(numONE())));;
- return mul(coefficient,power(Pi,numHALF()));
+ return coefficient * power(Pi,numHALF());
}
}
}
return gamma(x).hold();
}
-ex gamma_evalf(ex const & x)
+static ex gamma_evalf(ex const & x)
{
BEGIN_TYPECHECK
TYPECHECK(x,numeric)
return gamma(ex_to_numeric(x));
}
-ex gamma_diff(ex const & x, unsigned diff_param)
+static ex gamma_diff(ex const & x, unsigned diff_param)
{
ASSERT(diff_param==0);
- return power(x, -1); //!!
+ return power(x, -1); // FIXME
}
-ex gamma_series(ex const & x, symbol const & s, ex const & point, int order)
+static ex gamma_series(ex const & x, symbol const & s, ex const & point, int order)
{
- //!! Only handle one special case for now...
+ // FIXME: Only handle one special case for now...
if (x.is_equal(s) && point.is_zero()) {
ex e = 1 / s - EulerGamma + s * (power(Pi, 2) / 12 + power(EulerGamma, 2) / 2) + Order(power(s, 2));
return e.series(s, point, order);
}
REGISTER_FUNCTION(gamma, gamma_eval, gamma_evalf, gamma_diff, gamma_series);
+
+} // namespace GiNaC