RGAMMA

rgamma

Random numbers from the gamma distribution (inversion method)

         x = rgamma(n,a)
	Input	n	positive integer or a vector [lig,col] of integers
		a	positive real 

	Output	x	n-vector or a n-matrix of random numbers 
			chosen from Gamma distribution with parameter a
 
	( the gamma density function with parameter a is :
	   x --> x.^(a-1)exp(-x)./Gamma(a)1_{x>=0} )