ptGC function

Graphical Calculator for t-Curve Probabilities

Shades desired areas under a specified t-curve, returns numerical value of the area.

ptGC(bound,region="between",df=1,graph=FALSE)

Arguments

• bound: A numerical vector of length 1 or 2, indicating the boundary (respectively, boundaries) of shaded region on horizontal axis
• region: A character string. Possible values are "between" (when boundary consists of two numbers), "below", "above", and "outside" (again when boundary consists of two numbers)
• df: degrees of freedom of the distribution
• graph: produce graph?

Returns

Numerical value of area under curve over region. Also plots the t-curve with the shaded area.

Examples

#This gives P(-2 < t < 2) for a t-random variable with 1 degree of freedom:
ptGC(c(-2,2),region="between",df=1)

#This gives P(t < -1) for a t-random variable with 5 degrees of freedom:
ptGC(-1,region="below",df=5)

#This gives P( t < -2 OR t >2), for a t-random variable with 5 degrees of freedom:
ptGC(c(-2,2),region="outside",df=5)

Author(s)

Homer White hwhite0@georgetowncollege.edu