macro
Studentst t df cdf

#This macro reports the right tail area under the Students
#t distribution with df degrees of freedom.
#Algorithm comes from AMS55, p. 944, Eq. 26.5.27.

#Copyright Mathews and Malnar 12Nov01 All Rights Reserved

#Example calling statement:
#%studentst 2.4 12 k1
#Answer is cdf = 0.0167591

mconstant t df cdf x halfdf

note
note This macro runs very slowly. Please be patient.
note Macro running ...
note
brief 0
let x=df/(df+t*t)
let halfdf=df/2
%incbeta x halfdf 0.5 cdf
let cdf=cdf/2

brief
print cdf

endmacro