MATLAB: Can someone check the for loop

for loop

My for loop is suppose to return the minimum value found in the for loop, but it just keeps returning the last found value. How can I make it return the minimum value found?
This is my code:
    function m=myminimum (f,a,b);
    syms x ;
    for t=(a:b);
        m=subs(f(x),t);
    end
    m=min(m);
    end
Here is some sample data I have been running through the for loop along with what the answer it's suppose to be.
    myminimum(@(x) x^2+1,-3,2)
    ans =
    1
The answer my for loop provides is 5.
    myminimum(@(x) x^2+6*x-3,-2,0)
    ans =
    -11
The answer my for loop provides is -3.
How do I make my for loop return the minimum value of the for loop and not just the last found value?
Thanks

Best Answer

You need to tweak your loop a bit:
syms x
min_m = Inf;
for t=(a:b);
      m=subs(f(x),t);
      min_m = min(m, min_m);
end
m=min_m;
It initially sets ‘min_m’ to Inf, then in each iteration compares the current value of ‘m’ with the previous value and assigns ‘min_m’ to the minimum value of that comparison. It returns that value as ‘m’.
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