Different Output using For Loop vs Elementwise operation

Hello,

I have attached the code here. I see the results when compared using for loop and element wise operation are different. it is just not that the results are non-terminating or anything sometimes 2 spots past the decimal the results are differnt. Could someone tell me what I am doing wrong?

Thanks

Sai

x = linspace(0,pi,100);
y = cos(x);
z = size(x);
[row,col] = size(x);
for i = 1:col
    z(i) = 1-x(i)^2/2 + x(i)^4/24;
end
z1 = 1-x.^2+x.^4/24;
plot(x,z,x,z1);
Difference = z-z1 % To know the difference if the plot above isn't clear

Answer 1

[Paul]

x = linspace(0,pi,100);
y = cos(x);

This probably isn't what you want. Perhaps you mean z = zeros(size(x)) or something similar.

z = size(x);
[row,col] = size(x);
for i = 1:col
    z(i) = 1-x(i)^2/2 + x(i)^4/24;
end

Original code missing a divide by 2 on the second term in z1

%z1 = 1-x.^2+x.^4/24;
z1 = 1-x.^2/2+x.^4/24;
plot(x,z,x,z1);

●

Difference = z-z1 % To know the difference if the plot above isn't clear

Difference = 1×100

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

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[Sai Gudlur]

Thanks a ton. Yes I missed 2 & zeros(size(x))