Lambdify function to matrix

General Usage
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1

Hi there! Im trying to obtain a 20x20 matrix from the next code

fn = lambdify(t, [V, g, k])
ges = range(1, 2, 20); kes = range(1, 2, 20)
fn.(1, ges, kes)

But I obtain a vector…

20-element Vector{ComplexF64}:

Function “t” is a long expression obtained from solving linear system with SymPy Package.

Any ideas how can I handle this?
Thanks!

2

I’m not familiar with SymPy, but in this case, I’m guessing that you need to transpose one of your arrays, either ges or kes. Here’s an example with a made-up fn:

fn(x, y, z) = y*z + x 

ges = 1:5
kes = 1:5

fn.(1, ges, kes)

ges and kes are both vectors, so broadcasting will produce a vector:

5-element Vector{Int64}:
  2
  5
 10
 17
 26

However, running

fn.(1, ges, kes')

will produce a matrix:

5×5 Matrix{Int64}:
 2   3   4   5   6
 3   5   7   9  11
 4   7  10  13  16
 5   9  13  17  21
 6  11  16  21  26

and running

fn.(1, ges', kes)

will produce the same matrix transposed.

See the Julia manual here for details: Single- and multi-dimensional Arrays · The Julia Language: Broadcasting

3 Likes
3

You are absolutely right!
Thanks!