ellipticF

Incomplete elliptic integral of the first kind.

Category: Mathematics > Mathematical Functions

Syntax

F = ellipticF(phi, m)

Evaluates the integral from 0 to phi of 1/sqrt(1 - m*sin(t)^2).

Description

With phi = pi/2 it reduces to the complete integral ellipticK(m). It is the inverse of the Jacobi amplitude: if u = ellipticF(phi, m) then phi = jacobiAM(u, m). The time a pendulum needs to reach a given angle is given by this function.

Input arguments

phi
Amplitude angle in radians.
m
Parameter (m = k^2).

Output arguments

F
Array of the same size after broadcasting the inputs.

Example

Incomplete and complete cases

ellipticF(pi/4, 0.5)
ellipticF(pi/2, 0.5)
ellipticK(0.5)
Output
ans = 0.8260
ans = 1.8541
ans = 1.8541

See also

ellipticK ellipticE jacobiAM ellipticPi