density.f Function (GPL)

Syntax

density.f(<algebra>, degreesOfFreedom1(<integer>), degreesOfFreedom2(<integer>), <function>)

or 

density.f(<binning function>, degreesOfFreedom1(<integer>), degreesOfFreedom2(<integer>), <function>)

<algebra>. Graph algebra, such as x*y. Refer to Brief Overview of GPL Algebra for an introduction to graph algebra. The algebra is optional.

<binning function>. A binning function. The binning function is optional.

<integer>. degreesOfFreedom1 and degreesOfFreedom2 define the parameters for the distribution. These take positive integers and are required.

<function>. A valid function. Use scaledToData("false") when comparing densities with very different same sizes.

Description

Calculates the probability density of the F distribution. This is often used to add a distribution curve. If you don't see the graphic element for the distribution, check the parameters for the distribution and the range for the x axis scale.

Because this function does not estimate parameters from the data, it can be used only for comparison and not for fitting.

Examples

Figure 1. Example: Adding an F distribution curve
ELEMENT: line(position(density.f(x, degreesoffreedom1(5), degreesoffreedom2(2))))