AFNI program: p2t

*** NOTE: This program has been superseded by program 'cdf' ***

Usage #1: p2t p dof
  where p   = double sided tail probability for t-distribution
        dof = number of degrees of freedom to use
  OUTPUT = t value that matches the input p

Usage #2: p2t p N L M
  where p   = double sided tail probability of beta distribution
        N   = number of measured data points
        L   = number of nuisance parameters (orts)
        M   = number of fit parameters
  OUTPUT = threshold for correlation coefficient

Usage #3: p2t p
  where p   = one sided tail probability of Gaussian distribution
  OUTPUT = z value for which P(x>z) = p

Usage #4: p2t p dof N
  where p   = double sided tail probability for distribution of
                the mean of N  iid zero-mean t-variables
        dof = number of degrees of freedom of each t-variable
        N   = number of t variables averaged
  OUTPUT = threshold for the t average statistic
  N.B.: The method used for this calculation is the Cornish-
        Fisher expansion in N, and is only an approximation.
        This also requires dof > 6, and the results will be
        less accurate as dof approaches 6 from above!