Creating 3x201 matrix from set of numbers

Hi all,

I apologize in advance but I'm a newbie and don't have much experience with matlab - anyway here's what I'm trying to do.

I want to build a 201x3 matrix where every row has the same numbers, and the numbers in the columns go from 0 to 20e-10 with steps of 0.1e-10.

The matrix should look something like this:

[0 0 0
0.1 0.1 0.1
...
20 20 20]

I tried doing this by nesting three "for" loops in the following way:

for i = 0:0.1e-10:20e-10
    for j = 0:0.1e-10:20e-10
        for k = 0:0.1e-10:20e-10
        I = [i,j,k];
        end
    end
end

but instead of obtaining 201x1 vectors, i, j and k are just numbers (20e-10, to be precise).

I tried looking into other commands but I've been asked to do this specifically with nested for loops.

Sorry in advance if it's a silly question - and thanks to whoever takes the time to help!

Answer 1

[KLR]

Matt's answer is the most efficient. However since you mentioned you needed to do it specifically with for loops here's the code that will do it in a nested loop.. One thing I noticed in your loop was that your variable I was being overwritten by the latest value of i,j,k hence all you were seeing was the last value of i,j,k.

Matrix=zeros(201,3); 
for i=1:1:200
    for j=1:1:200
    for k=1:1:200
    I=i/10;
    Matrix(i+1,:)=I;
end
end
end

[chesapeakedipper]

thanks, this is great :)

Answer 2

[Matt J]

I=(0:0.1e-10:20e-10).' *[1,1,1];

[chesapeakedipper]

way simpler than what i tried - thanks a lot :)