# Loop my code until c vector is zero or less

3 views (last 30 days)
Jordan Whitehurst on 30 Jan 2018
Edited: Soumya Saxena on 2 Feb 2018
here's my code (if the quality is crap, my only excuse is I don't like coding)
A = [1 0.5 2; 0 1 0.5; 2 1 1];
% | 1 .5 2 |
% | 0 1 .5 | --> What the matrix looks like
% | 2 1 1 |
c = [20 15 12];
emptyZ = zeros(1,3); % The zeros under the slack varibles of length m
Fullc = [0 c emptyZ]; % The string of values in the Obj row
b = [7; 10; 12;];
I = eye(3); % Identity matrix of size m when user inputs value
Q = [b A I; Fullc]
L = size(Q);
[val, idx] = max(Q(:));
[row, col] = ind2sub(size(Q),idx);
j = col;
bQ = Q(:,1);
a = bQ./Q(:,j);
a(a == 0) = NaN;
[valP, idxP] = min(a);
i = idxP; % This is our row i
v = ones(L(1),1); % Creates vector of ones
v(i) = 1./Q(i,j); % The pivot element in vector v is replaced by 1/Q
P1 = diag(v); % Sets all values in P1 in the diagonal of zeros and ones
P2 = eye(L(1)); % Opens identity matrix by length of rows
P2(:,i) = -Q(:,j); % Replaces the ith column of P2 by the negative column j in Q
P2(i,i) = 1; % Sets pivot element co-ordinates to 1
Q = P2*P1*Q % Complete pivot step
I'm trying to create a code that will do the simplex method without using linprog... :/ I have a piece of code which allows the user to enter the values in the appropriate arrays so I didn't need to put that in this, I used some random data to show my A, b and c matrices. I think all I need is my code to loop until the c vector has zero or less in that array. Any help would be greatly appreciated, many thanks
Walter Roberson on 30 Jan 2018

Soumya Saxena on 2 Feb 2018
Edited: Soumya Saxena on 2 Feb 2018

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