 
 
 
7.3.15  Lower incomplete γ function
The lower incomplete γ function is defined by 
The igamma command computes
the lower incomplete γ function.
- 
igamma takes two mandatory arguments and one optional
argument:
- 
a, a number.
- b, a positive real number.
- Optionally, the number 1.
 
- igamma(a,b) returns γ(a,b).
- igamma(a,b,1) returns a normalized version of the
function; namely γ(a,b)/Γ(a).
Examples
since Γ(4)=6 and 2.11660866731/6=0.352768111218.
 
 
