# DedekindEta DedekindEta[τ]

gives the Dedekind eta modular elliptic function .

# Details • Mathematical function, suitable for both symbolic and numerical manipulation.
• DedekindEta is defined only in the upper half of the complex τ plane. It is not defined for real τ.
• The argument τ is the ratio of Weierstrass halfperiods .
• DedekindEta satisfies where is the discriminant, given in terms of Weierstrass invariants by .
• For certain special arguments, DedekindEta automatically evaluates to exact values.
• DedekindEta can be evaluated to arbitrary numerical precision.
• DedekindEta automatically threads over lists.
• DedekindEta can be used with CenteredInterval objects. »

# Examples

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## Basic Examples(2)

Evaluate numerically:

Plot over a subset of the reals:

## Scope(14)

### Numerical Evaluation(4)

Evaluate numerically:

Evaluate to high precision:

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

Evaluate efficiently at high precision:

DedekindEta can be used with CenteredInterval objects:

### Specific Values(2)

Value at fixed point:

### Visualization(2)

Plot the DedekindEta function for various parameters:

Plot the real part of the DedekindEta function in three dimensions:

Plot the imaginary part of the DedekindEta function in three dimensions:

### Function Properties(6)

Complex domain of DedekindEta:

DedekindEta is a periodic function:

DedekindEta is an analytic function on its domain:

It is not an entire function, however:

It has both singularities and discontinuities:

DedekindEta is not injective over the complexes:

DedekindEta is not surjective:

## Applications(2)

Plot the DedekindEta in the upperhalf complex plane:

The modular discriminant:

Relation with DedekindEta:

## Properties & Relations(2)

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

With exact input, the answer is correct:

Because DedekindEta is a numerical function with numeric arguments, it might be considered a numeric quantity but because of its boundary of analyticity, it might not be evaluatable to a number: