Symbolic matrix exponential

General Usage
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1

Hello All! I am fairly new to Julia.

I want to find the matrix exponential of a symbolic matrix. How to do this?
When I use the Symbolics and LinearAlgebra packages together, it doesn’t work:

using Symbolics
using LinearAlgebra

function run()
@variables a b c t
M = [ -a b 0
     1 c -a
     0 1 0]
Mt = M*t
expMt = exp(Mt)
print(expMt[1,1])
end

@time run()

Any help will be very appreciated!

2

Open an issue on Symbolics.jl. This isn’t implemented, and I’m not convinced there is a general symbolic solution that can be given on this operation. It’s worth a dev discussion.

1 Like
3

Okay. I did that. I hope this gets implemented. Thanks.

4

I’m not convinced it’s possible in general :sweat_smile: .

I just took a look and saw SymPy can only do it if the Jordan normal form exists for A. That’s probably a fine enough restriction.

1 Like