# Save each vector iteration into a matrix

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Abdur Rahim on 31 Oct 2016
Commented: Abdur Rahim on 1 Nov 2016
I have 2 vectors, a and b and the sum of both is v.The time t ranges from 0 to 20 and i would like to save each iteration of v (a vector) into a matrix (where there are 21 vectors thus 3x21). Currently this code goes through each iteration however overwrites all of them and only shows the last value of t. Im am also unsure where the 'if' command is suitable in this circumstance.
for t=1:20;
a = [t,cos(t),0]';
b = [0,0,sin(t)]';
v = a + b;
end

Cory Johnson on 1 Nov 2016
There are lots of ways to organize data in MATLAB. Below I have shown 3 ways to do this. I think you're looking for the last method.
%%Cell Array
for t=0:20;
a{t+1} = [t,cos(t),0]';
b{t+1} = [0,0,sin(t)]';
v{t+1} = a{t+1} + b{t+1};
end
%%Structure array
for t=0:20;
vec(t+1).a = [t,cos(t),0]';
vec(t+1).b = [0,0,sin(t)]';
vec(t+1).v = vec(t+1).a + vec(t+1).b;
end
%%Only save v
v = [];
for t=0:20;
a = [t,cos(t),0]';
b = [0,0,sin(t)]';
v = [v, (a + b)];
end
Hope that helps!

#### 1 Comment

Abdur Rahim on 1 Nov 2016
It's greats having all those methods because I can use the format for future codes, its helped me a lot thanks.