Error: Unable to convert 'ureal' to 'sym'

Hi

I am working with the Robust Control Toolbox and want to pass values of type 'ureal' to a symbolic matrix through a function.

It works fine if I write the matrix in my function manually, e.g.

x = ureal('x',10,"Percentage",20);
my_fun(x)

function A = my_fun(x)
 A = [x 1; 1 x]
end

However, I want to load my matrix from a .mat file instead of instead writing it manully, e.g.

syms x
A = [x 1; 1 x];
save('matrix.mat','A')

x = ureal('x',10,"Percentage",20);

my_fun(x)

function A = my_fun(x)
 loaded_matrix = load('matrix.mat')
 A_symbolic = loaded_matrix.A
 A = subs(A_symbolic)
end

This does not work and I get the error "Error: Unable to convert 'ureal' to 'sym".

Is there a workaround for this problem? How do I pass my ureal-type to my function such that I get a numeric matrix?

Hope someone can help me!

Answer 1

[Pranav Verma]

Hi Jakob,

Try replacing the last line of the my_fun,

A = subs(A_symbolic)

to,

A = sym(A_symbolic)

Hope this helps.

Thanks

[Jakob Poulsen]

Hi Pranav,

Thank you for your aswer.

Maybe I formulated my question wrong. I want my output from my_fun(x) to be a numeric umat matrix.