# Taking values from a Matrix and Inputting into an equation, using Loops

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RS on 23 Jul 2020
Commented: Serhii Tetora on 23 Jul 2020
Hello.
I have a matrix say: A = [1 2 3 4 5 6 7] and an eqaution y = x^2
I need to find a way to take each value of the matrix and input it into y in an automated way, say using For loops. I am also trying to do this by not making the resulting values of y as a matrix i.e. I just want the answer y gives for each value taken from a to be stored as a number and not a matrix.
I am a relative beginner to MATLAB and have no idea how to do this.
Any help greatly appreciated.

Serhii Tetora on 23 Jul 2020
A = [1 2 3 4 5 6 7];
for i = 1:length(A)
x = A(i);
y(i) = x^2;
end
y
##### 2 CommentsShowHide 1 older comment
Serhii Tetora on 23 Jul 2020
A = [1 2 3 4 5 6 7];
for i = 1:length(A)
x = A(i);
y(i) = x^2;
eval(sprintf('Ans%d = y(i)',i))
end

William Alberg on 23 Jul 2020
Hello Omar
If you want to replace "y" with one of the values in "A", you can do it the following way:
A = 1:7;
syms x y
eq = y == x^2;
for i = 1:length(A)
eq_temp = subs(eq, y, A(i))
end
If you want to calculate y, i would recommed doing it the following way, where "y = f(x)":
f(x) = x^2;
for i = 1:length(A)
val_temp = f(A(i))
end
William Alberg on 23 Jul 2020
I did not see Serhii's repley.
I also misunderstood, i thought you wanted the equation to be in symbolic format.