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Last Modified: January 12, 2018

Computes the continuous F cumulative distribution function (CDF), the probability that an F variate takes on a value less than or equal to the quantile of the random variable.

An F variate is the ratio of two chi-squared random variable.

Quantile of the continuous random variable.

This input must be equal to or greater than 0.

**Default: **0.5

Number of degrees of freedom of the first chi-squared variate that forms the F variate.

This input must be greater than 0.

**Default: **1

Number of degrees of freedom of the second chi-squared random variable that forms the F variate.

This input must be greater than 0.

**Default: **1

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an **error in** input and an **error out** output so that the node can respond to and communicate errors that occur while code is running. The value of **error in** specifies whether an error occurred before the node runs. Most nodes respond to values of **error in** in a standard, predictable way.

**Default: **No error

Cumulative probability that the continuous random variable has a value less than or equal to **x**.

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

**error in** input and an **error out** output so that the node can respond to and communicate errors that occur while code is running. The value of **error in** specifies whether an error occurred before the node runs. Most nodes respond to values of **error in** in a standard, predictable way.

The following equation defines the continuous CDF of an F variate.

$pdf\left(x\right)=\frac{\mathrm{\Gamma}\left[({k}_{1}+{k}_{2})/2\right]{({k}_{1}/{k}_{2})}^{{k}_{1}/2}{x}^{({k}_{1}-2)/2}}{\mathrm{\Gamma}({k}_{1}/2)\mathrm{\Gamma}({k}_{2}/2){[1+({k}_{1}/{k}_{2})x]}^{({k}_{1}+{k}_{2})/2}}$

where

*x*is the quantile of the continuous random variable*k*_{1}is the degrees of freedom of the first chi-squared variate that forms the F variate*k*_{2}is the degrees of freedom of the second chi-squared variate that forms the F variate-
$\mathrm{\Gamma}(k/2)$ is the gamma function with argument
*k*/2

**Where This Node Can Run: **

Desktop OS: Windows

FPGA: Not supported

Web Server: Not supported in VIs that run in a web application