# JacobiCD

JacobiCD[u,m]

gives the Jacobi elliptic function .

# Details

• Mathematical function, suitable for both symbolic and numerical manipulation.
• , where .
• is a doubly periodic function in u with periods and , where is the elliptic integral EllipticK.
• JacobiCD is a meromorphic function in both arguments.
• For certain special arguments, JacobiCD automatically evaluates to exact values.
• JacobiCD can be evaluated to arbitrary numerical precision.
• JacobiCD automatically threads over lists.

# Examples

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## Basic Examples(4)

Evaluate numerically:

Plot the function over a subset of the reals:

Plot over a subset of the complexes:

Series expansions at the origin:

## Scope(33)

### Numerical Evaluation(4)

Evaluate to high precision:

The precision of the output tracks the precision of the input:

Evaluate for complex arguments:

Evaluate JacobiCD efficiently at high precision:

### Specific Values(3)

Simple exact answers are generated automatically:

Some poles of JacobiCD:

Find a zero of :

### Visualization(3)

Plot the JacobiCD functions for various values of parameter:

Plot JacobiCD as a function of its parameter :

Plot the real part of :

Plot the imaginary part of :

### Function Properties(8)

JacobiCD is -periodic along the real axis:

JacobiCD is -periodic along the imaginary axis:

JacobiCD is an even function in its first argument:

is an analytic function of for :

It is not, in general, an analytic function:

It has both singularities and discontinuities for :

is neither nondecreasing nor nonincreasing:

is not injective for any fixed :

is not surjective for any fixed :

JacobiCD is neither non-negative nor non-positive:

JacobiCD is neither convex nor concave:

### Differentiation(3)

First derivative:

Higher derivatives:

Plot higher derivatives for :

Derivative with respect to :

### Integration(3)

Indefinite integral of JacobiCD:

Definite integral of an even integrand over the interval centered at the origin:

This is twice the integral over half the interval:

More integrals:

### Series Expansions(3)

Taylor expansion for :

Plot the first three approximations for around :

Taylor expansion for :

Plot the first three approximations for around :

JacobiCD can be applied to a power series:

### Function Identities and Simplifications(3)

Primary definition:

Parity transformations and periodicity relations are automatically applied:

Automatic argument simplifications:

### Function Representations(3)

Representation in terms of trigonometry functions and JacobiAmplitude:

Relation to other Jacobi elliptic functions:

## Applications(4)

Derivatives of Jacobi elliptic functions with respect to parameter :

Conformal map from a unit triangle to the unit disk:

Show points before and after the map:

Solution of the PoissonBoltzmann equation :

Check solution using series expansion:

Construct lowpass elliptic filter for analog signal:

Compute filter ripple parameters and associate elliptic function parameter:

Use elliptic degree equation to find the ratio of the pass and the stop frequencies:

Compute corresponding stop frequency and elliptic parameters:

Compute ripple locations and poles and zeros of the transfer function:

Compute poles of the transfer function:

Assemble the transfer function:

Compare with the result of EllipticFilterModel:

## Properties & Relations(3)

Compose with inverse functions:

Use PowerExpand to disregard multivaluedness of the inverse function:

Solve a transcendental equation:

Integrals:

## Possible Issues(2)

Machine-precision input is insufficient to give the correct answer:

Currently only simple simplification rules are built in for Jacobi functions:

Wolfram Research (1988), JacobiCD, Wolfram Language function, https://reference.wolfram.com/language/ref/JacobiCD.html.

#### Text

Wolfram Research (1988), JacobiCD, Wolfram Language function, https://reference.wolfram.com/language/ref/JacobiCD.html.

#### CMS

Wolfram Language. 1988. "JacobiCD." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/JacobiCD.html.

#### APA

Wolfram Language. (1988). JacobiCD. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/JacobiCD.html

#### BibTeX

@misc{reference.wolfram_2024_jacobicd, author="Wolfram Research", title="{JacobiCD}", year="1988", howpublished="\url{https://reference.wolfram.com/language/ref/JacobiCD.html}", note=[Accessed: 24-June-2024 ]}

#### BibLaTeX

@online{reference.wolfram_2024_jacobicd, organization={Wolfram Research}, title={JacobiCD}, year={1988}, url={https://reference.wolfram.com/language/ref/JacobiCD.html}, note=[Accessed: 24-June-2024 ]}