tcdf
tcdf is the name commonly used for the cumulative distribution function of the Student's t-distribution. It returns the probability that a t-distributed random variable with a given number of degrees of freedom is less than or equal to a specified value.
Parameters and domain: The function takes x, the value at which to evaluate the CDF, and df
Formula and interpretation: A commonly used closed-form representation is F(x; df) = 0.5 * I_z(df/2, 0.5) for x
Usage and connections: tcdf is used to compute p-values for t-tests and to obtain CDF values for
Software implementations: Implementations include MATLAB's tcdf(x, df) and SciPy's scipy.stats.t.cdf(x, df). Other environments provide equivalent functions