dariat: Calculate and draw the area under the t distribution

In dusadrian/statistics: Miscellanea Functions For Intro Stats Classes

Calculate and draw the area under the t distribution

Description

A function similar to "daria", with the only difference it uses the t instead of the z distribution. In addition, the function expects an additional parameter for the degrees of freedom.

Usage

dariat(area, t1, t2, df, draw = FALSE)

Arguments

area	The required area
t1	First t value, in the interval +/- 4
t2	Second t value, in the interval +/- 4
df	Degrees of freedom
draw	Logical; if TRUE, draw the area

Details

In the argument area, the function accepts:

"l", "u", "left" and "under" for the area to the left of z,

"r", "o", "a", "right" "over" and "above" for the area to the right of z

"b" and "between" for the area between two z values.

z values smaller than -4 and greater than +4 are truncated to these values, since the area to the left and to the right of these values is practically equal to zero.

Author(s)

Adrian Dusa

See Also

pt, qt

Examples

# for 100 degrees of freedom
dariat("between", -1.96, 1.96, df = 100)

dariat("over", -1, df = 100)

dariat("under", -1, df = 100)

dariat("over", 2, df = 100, draw = TRUE)

dusadrian/statistics documentation built on Jan. 15, 2025, 4:13 a.m.