Need help to create a matrix for the use of intlinprog!

Hello,

I am a beginner. I have the following sample vector named Zvalues:

 Variable Name         Zvalues
 Z11                      0
 Z12                      0
 Z13                      1
 Z21                      0
 Z22                      1
 Z23                      0
 Z31                      0
 Z32                      1
 Z33                      0

I have created a zero 3x9 sized matrix as following:

 Y= zeros(3, 9);

I want to fill this matrix with an if condition, as the following example:

 if Zvalues(3,1) == 1;
 Y(1,3) = 1;

 if Zvalues(5,1) == 1;
 Y(2,5) = 1;

 if Zvalues(8,1) == 1;
 Y(3,8) = 1;

The following matrix is what I want to reach at the end. 'Y's represent variable names, they are not a part of the matrix .

Y11 Y12 Y13 Y21 Y22 Y23 Y31 Y32 Y33

0   0   1   0   0   0   0   0   0  
0   0   0   0   1   0   0   0   0  
0   0   0   0   0   0   0   1   0

I thought that I might use for loop and if commands, however, I couldn't really successfully create a code for it. This is what I could have think of:

 for k=1:i*m
     if Zvalues(k,1) == 1
        Y(1,k) = 1
     end
 end

where, i*m is 9. The formulation is absolutely wrong. Please help me to fix it. Thanks.

The question is edited to make it more clear. If you see anything unclear, please let me know.

Answer 1

[Stephen23]

Just use sub2ind:

>> Z = [0;0;1;0;1;0;0;1;0]
Z =
     0
     0
     1
     0
     1
     0
     0
     1
     0
>> Y = zeros(3,9);
>> Y(sub2ind(size(Y),1:nnz(Z),find(Z).')) = 1
Y =
     0     0     1     0     0     0     0     0     0
     0     0     0     0     1     0     0     0     0
     0     0     0     0     0     0     0     1     0

[Taner Cokyasar]

This was exactly what I was looking for. Thank you so much Stephen.

dpb, you typed the same thing as well. I could have understood yet. Thanks for all your answers.

Answer 2

[KSSV]

clc; clear all ;
z = [0
 0
 1
 0
 1
 0
 0
 1
 0];

sigmas = zeros(3, 9);
Ys = zeros(3, 9);

   if z(3,1) == 1;
      sigma(1,3) = 1;
      Ys(1,3) = 1;
   end
   if z(5,1) == 1;
      sigma(2,5) = 1;
      Ys(2,5) = 1;
   end
   if z(8,1) ==1;
      sigma(3,8) = 1;
      Ys(3,8) = 1; 
   end

   Aeq = [sigma, Ys]

[Taner Cokyasar]

Dr. Siva,

That is what I have written. I need to build a code for different situations. What if Zvalues is as following:

 0
 1
 0
 0
 0
 1
 0
 1
 0

So, what I am asking is to generalize these if conditions. Zvalues represents a two indices variable Zim, where i=m=3 in this example (They might have different values in general). The dimension of sigmas and Ys matrices are (i)x(i*m). So, even constructing a code to generate a sigmas matrix is actually enough. I can just type Aeq = [sigmas; sigmas]. But, my problem is to create a sigmas (or Ys, doesn't matter. They are basically same) matrix.

[dpb]

Isn't this the same question we've been discussing at <help-for-creating-constraint-with-if-conditions>? The solution I gave there is general (that's why I went the route I did to produce one that is independent of size simply given the input array).

[Taner Cokyasar]

That is true dpb. However, I couldn't make your codes work :(. Your code is really confusing to me. For my first question given in that link, you used 'm' for the whole matrix. I changed that 'm' and it worked. However, for my second question, since I couldn't properly understand the way you are doing it, I couldn't fit your codes into mine. I am pretty sure that you understood the problem and able to provide the correct formulation, however I can't understand it. I simplified the problem in the following link:

http://www.mathworks.com/matlabcentral/answers/294781-intlinprog-matrix-creation-help-needed

Maybe, you can take a look at there. I would really appreciate. Thanks.