Function builtin_pt 

fn builtin_pt(
    args: &[RValue],
    named: &[(String, RValue)],
) -> Result<RValue, RError>

Student’s t cumulative distribution function.

Uses the regularized incomplete beta function: pt(x, df) = 1 - 0.5 * I_{df/(df+x^2)}(df/2, 1/2) for x >= 0

@param q quantile vector @param df degrees of freedom @return numeric vector of probabilities