# exponential matrix exp(A)

What is the maximum size of a square matrix A to calculate exp(A)

exponential matrix exp(A)

asked
**
2012-03-08 02:51:07 -0500
**

This post is a wiki. Anyone with karma >750 is welcome to improve it.

What is the maximum size of a square matrix A to calculate exp(A)

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answered
**
2012-03-08 06:30:35 -0500
**

This post is a wiki. Anyone with karma >750 is welcome to improve it.

At the same time, experimentation with `random_matrix(ZZ,i,i)`

suggests that Maxima hits a wall with this already when `i=4`

. `RR`

doesn't look much better, and

```
sage: m = random_matrix(RDF,4,4)
sage: m.exp?
```

basically says as much. But

```
sage: m = random_matrix(RDF,4,4)
sage: exp(m)
[ 0.360479628838 -0.145794589097 1.4781378783 0.316593839994]
[ 0.317770329736 0.0984841855079 -0.733966866354 -0.820812967827]
[ -1.58402218787 0.783288361066 0.965206766202 0.919221986577]
[-0.254553742946 0.837705408602 -2.47262343564 1.63085510321]
sage: m = random_matrix(RDF,10,10)
sage: exp(m)
```

looks much better. So the answer to your question depends on what you are exactly looking for.

Indeed, using RDF or CDF will probably scale *much* better.

0

answered
**
2012-03-08 04:58:25 -0500
**

This post is a wiki. Anyone with karma >750 is welcome to improve it.

I don't think there are any hard-coded size limits.

Asked: **
2012-03-08 02:51:07 -0500
**

Seen: **690 times**

Last updated: **Mar 08 '12**

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