Using part of data as variables

Hi, I'm trying to analyze some data exported from another program. This data file has 4 columns and a couple of hundred rows. I'm interested in the data from the 1st and the 4th column, but only for parts of it. The parts in which I am interested can be deduced from the 3th column. Example:

 x   y   z   T
 0   1   0   12
 1   1   0   13
 4   1   0   10
 5   1   0   14
 6   1   .1  17
 2   1   .1  11
 7   1   .1  12
 8   1   .5  14

So to clarify... I want to create a variable x (for z0, z0.1, z0.5 etc.) and a T variable for the same z's...

I just started with using 'if' functions and thought I could maybe use it for this. However, I don't know how. I know the next example isn't correct, but maybe it clarifies what I've got in mind...

if data(,3) == 0
  save corresponding rows of column 1 to x_z00 & T_z00
end

Does anyone have an idea how I could solve this problem?

[Stephen23]

Here is a discussion of why meta-data (such as an index) should not be in a variable name:

http://www.mathworks.com/matlabcentral/answers/225435-save-variable-as-string-from-user-input

And these are highly relevant too:

https://www.mathworks.com/help/matlab/matlab_prog/string-evaluation.html

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Answer 1

[Azzi Abdelmalek]

v=[  0   1   0   12
1   1   0   13
4   1   0   10
5   1   0   14
6   1   .1  17
2   1   .1  11
7   1   .1  12
8   1   .5  14 ]
idx=v(:,3)==0
out=v(idx,[1 4])