twotailt(tval, df), tval a REAL scalar, df > 0 REAL. |

twotailt(tval,df) computes the two tailed P value for a Student's t value of tval with df degrees of freedom. It is implemented as a macro. In the simplest usage, tval and df are REAL scalars with df > 0. However, if one argument is a scalar, the other argument can be a REAL vector, matrix or array and the result has the same size and shape. When both arguments are not scalars, they both must have the same size and shape. See also cumstu().

Gary Oehlert 2003-01-15