How to get rid of the error An array for multiple LHS assignment cannot contain LEX_TS_STRING

New to programing in matlab. I am currently trying to make a MATLAB program that will find the critical values of a multi-variable function and tell me whether each are a minimum, maximum, or saddle point. Unfortunately I always get the error : An array for multiple LHS assignment cannot contain LEX_TS_STRING

Any help will be very appreciated.

here's the code:

function [c,d] = critcalpoints(f)

syms x y
f(x,y)=x^3-3*x^2+5*x*y-7*y^2;
gradf = jacobian(f(x,y));
hessmatf = jacobian(gradf,[x,y]);
[xcr,ycr]=solve(gradf(1),gradf(2));
H1=subs(hessmatf,[x,y],[xcr(1),ycr(1)]);
H2=subs(hessmatf,[x,y],[xcr(2),ycr(2)]);
eig(H1);
eig(H2);
c = double(eig(H1));
d = double(eig(H2));
if (c(1) > 0 && d(1) > 0) || (c(2) > 0 && d(2) > 0)
print([xcr,ycr],' is a minimum')
elseif (c(1) < 0 && d(1) < 0) || (c(2) < 0 && d(2) < 0)
print( [xcr, ycr], ' is a maximum')
elseif (c(1) < 0 && d(1) > 0) || (c(1) > 0 && d(1) < 0)
print( [xcr, ycr], ' is a saddle point')
elseif (c(2) < 0 && d(2) > 0) || (c(2) > 0 && d(2) < 0)
print( [xcr, ycr], ' is a saddle point')
elseif (c(1)==0 || d(1)==0)
print( [xcr, ycr], ' is degenerate')
elseif (c(2)==0 || d(2)==0)
print( [xcr, ycr], ' is degenerate')
end

Answer 1

[Walter Roberson]

What are you passing in? You have a parameter named 'f' and then you try to store into f(x,y) but that will typically fail with incompatible datatypes if you actually passed anything in.

The MATLAB print() function is for saving figures to a file. You should consider looking at fprintf()