How can I extract matrices from rows of other matrices.

Hello everyone,

I am working on a project for MCDM. I am using AHP method. I need help to apply an algorithm.

I have 4 matrices of 199X4 doubles. i.e.

row1 = [C11 C12 C13 C14];

row2 = [C21 C22 C23 C24];

row3 = [C31 C32 C33 C34];

row4 = [C41 C42 C43 C44];

where C11.....C44 are 199X1 doubles each.

Now, I have to make pairwise comparision matrix from rows of each given matrices. like

CompMat = [row1(1,:); row2(1,:); row3(1,:); row4(1,:)];

Next, I have to apply a function(Which I have already made) to calculate Consistancy. i.e.

CR = ConsistencyAHP( CompMat );

Now, task is to write a script using loops which can give me CR vector for every matrices formed from first row to 199th row.

Thanks in advance.

Answer 1

[Ameer Hamza]

Using a for-loop will be easiest

row1 = [C11 C12 C13 C14];
row2 = [C21 C22 C23 C24];
row3 = [C31 C32 C33 C34];
row4 = [C41 C42 C43 C44];

CR = zeros(size(row1,1),1); % does ConsistencyAHP return a scalar??
for i=1:size(row1,1)
    CompMat = [row1(i,:); row2(i,:); row3(i,:); row4(i,:)];
    CR(i) = ConsistencyAHP(CompMat);
end

[Ashwani Kumar MAlviya]

Hii Ameer,

Thank you very much for your efforts.

Yes, ConsistancyAHP returns scalar.

Also, I want to inform you that in the line

CompMat = [row1 (i, :); row2 (i, :); row3 (i, :); row4 (i, :)];

I am getting error as

Error: File: analysis.m Line: 304 Column: 23

Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters.

Please suggest me whts went wrong.

[Ameer Hamza]

Remove the space between row1 and (i, :); Write it exactly like this

CompMat = [row1(i, :); row2(i, :); row3(i, :); row4(i, :)];
              %^ No spaces here and after row2, row3 and row4

[Ashwani Kumar MAlviya]

Dear Ameer,

Thanks it worked.

There was some syntex errors I figured it out. It is great help.

Thank you very much

[Ashwani Kumar MAlviya]

row1 = [C11 C12 C13 C14];
row2 = [C21 C22 C23 C24];
row3 = [C31 C32 C33 C34];
row4 = [C41 C42 C43 C44];

CR = zeros (size (row1,1), 1); % Yes, ConsistencyAHP return a scalar ??
for i = 1: size (row1,1)
    CompMat = [row1(i, :); row2(i, :); row3(i, :); row4(i, :)];
    CR (i) = ConsistencyAHP (CompMat);
end

[Ameer Hamza]

I am glad to be of help.