# JacobiEllipticI

Advanced Analysis Library Only

void JacobiEllipticI (double u, double k, double *cn, double *sn, double *dn, double *phi);

## Purpose

Determines the Jacobian elliptic functions cn, dn, and sn, which the following equations define:

and

## Parameters

Input
Name | Type | Description
u | double-precision | The input parameter.
k | double-precision | The integrand parameter.
Output
Name | Type | Description
cn | double-precision | The value of the Jacobi elliptic function cn.
sn | double-precision | The value of the Jacobi elliptic function sn.
dn | double-precision | The value of the Jacobi elliptic function dn.
phi | double-precision | The upper limit of the integral that defines the function.

## Return Value

None.