Passing Symbolic Variables into a function as parameters

I am trying to write a function that takes 2 symbolic equations, as well as the symbolic variables to solve for, in as parameters. The function is then supposed to solve for the 2 symbolic variables and then eliminate any solutions that contain imaginary numbers as you can see below.

syms x y

f = (x*y) == 1;
g = (x)+y == 0;
solution = testfunct(f, g, {x}, {y})

function [sols1 sols2] = testfunct(eq1, eq2 , t, s)

    sols = solve(eq1, eq2, [t s]);

    sols1 = sols.t(imag(sols.t)==0); % "Reference to non-existent field 't'"
    sols2 = sols.s(imag(sols.s)==0);
end

I receive an error saying seen in the comment. Now if this code works if I replace that line with

sols1 = sols.x(imag(sols.x)==0); %and the same for sols2 replacing x with y

Running whos gives me that t is a cell containing 1x1 sym which is x so I tried

sols1 = sols.(t{1,1})

which returns an error saying that 'Argument to dynamic structure reference must evaluate to a valid field name.' Even though t{1,1} = x and class(t{1}) = 'sym'.

Answer 1

[Ameer Hamza]

If you are willing to use the same variable name inside the function, then you can try this

syms x y

f = (x*y) == 1;
g = (x)+y == 0;
solution = testfunct(f, g, x, y) % <==== no need to pass as cell

function [sols1 sols2] = testfunct(eq1, eq2 , x, y)

    sols = solve(eq1, eq2, [x y]);

    sols1 = sols.x(imag(sols.x)==0); % "Reference to non-existent field 't'"
    sols2 = sols.y(imag(sols.y)==0);
end

If you want to use t and s as input variables, then you can use the following syntax

syms x y

f = (x*y) == 1;
g = (x)+y == 0;
solution = testfunct(f, g, x, y) % <==== no need to pass as cell

function [sols1 sols2] = testfunct(eq1, eq2 , t, s)

    sols = solve(eq1, eq2, [t s]);

    t_char = char(t);
    s_char = char(s);
    sols1 = sols.(t_char)(imag(sols.(t_char))==0); % "Reference to non-existent field 't'"
    sols2 = sols.(s_char)(imag(sols.(s_char))==0);
end

[Benjamin Colety]

Thanks!

[Ameer Hamza]

I am glad to be of help.