gamma - The gamma function.
gamma(x) evaluates the gamma function at all the elements of x . The gamma function is defined by :
/+oo | x-1 -t gamma(x) = | t e dt /0
and generalizes the factorial function for real numbers ( gamma(n+1) = n! ).
// simple examples gamma(0.5) gamma(6)-prod(1:5) // the graph of the Gamma function on [a,b] a = -3; b = 5; x = linspace(a,b,40000)'; y = gamma(x); xbasc() c=xget("color") xset("color",2) plot2d(x, y, style=0, axesflag=5, rect=[a, -10, b, 10]) xset("color",c) xtitle("The gamma function on ["+string(a)+","+string(b)+"]") xselect()
W. J. Cody and L. Stoltz (code from Netlib (specfun))