My matlab code give me bad results - using the MARCOS algorithm - matlab

I followed all the steps of the MARCOS (Measurement of alternatives and ranking according to Compromise solution) algorithm. I tried it and I follow the algorithm but always the code gave me the same results.
Everything is okay, the problem is FKm and FKp, always give the same values.
For example, let's try the alternatives are:
Networks:
8 50 4 134 12 67
66 74 1 50 42 75
42 60 49 285 5 68
47 60 45 68 6 63
8 50 4 145 17 61
61 83 1 44 11 63
48 60 59 288 4 75
45 60 21 95 4 33
and the weights:
weights= 0.0360 0.1240 0.1040 0.3250 0.3070 0.1020
Code:
function Score = MARCOS(Networks,Weights)
global CostperByte;
global Security;
global DataRate;
global PacketDelay;
global PacketJitter;
global PacketLoss;
%NumberOfNetworks;
CostperByte=1;
Security=2;
DataRate=3;
PacketDelay=4;
PacketJitter=5;
PacketLoss=6;
SIZE = size(Networks);
NumberOfNetworks = SIZE(1);
NumberOfCriteria = SIZE(2);
AAI=zeros(1,NumberOfCriteria);
AI= zeros(1,NumberOfCriteria);
for j=1:NumberOfCriteria
if ( (j==DataRate) || (j==Security) ) % benifit
AAI(1,j)= min (Networks(:,j));
AI(1,j)=max (Networks(:,j));
else
AAI(1,j)=max (Networks(:,j));
AI(1,j)=min(Networks(:,j));
end
end
Networks= [ AAI ; Networks ; AI];
SIZE = size(Networks);
NumberOfNetworks = SIZE(1);
NumberOfCriteria = SIZE(2);
Normalization=[];
for i=1:NumberOfNetworks
for j=1:NumberOfCriteria
if ( (j==DataRate) || (j==Security) ) %%%%%%% data rate, security, bandwidth
Normalization(i,j) = ( Networks (i,j)) / AI(1,j) ;
else %%%%%%% jitter, delay,st,
Normalization(i,j) = AI(1,j) / ( Networks (i,j));
end
end
end
for i=1: NumberOfNetworks
for j=1: NumberOfCriteria
W(i,j)=Normalization(i,j)*Weights(j);
end
end
Saai= sum(W(1,:));
Sai= sum(W(NumberOfNetworks,:)) ;
W=W(2:NumberOfNetworks-1,:);
SIZE = size(W );
NumberOfNetworks = SIZE(1);
NumberOfCriteria = SIZE(2);
for i=1:NumberOfNetworks
S(i) =sum( W(i,:));
end
for i = 1: NumberOfNetworks
Km(i) = S(i)/ Saai;
Kp(i) = S(i) / Sai;
end
for i=1:NumberOfNetworks
FKm(i) = Kp(i)/( Kp(i)+Km(i));
FKm(i)
FKp(i) = Km(i)/( Kp(i)+Km(i));
end
for i=1:NumberOfNetworks
FK(i)= ( FKm(i) + (FKp(i)) ) / ( 1+ ( (1-FKp (i))/FKp(i) ) + ( (1-FKm(i))/FKm(i) ) ) ;
end
%%summation%%
Results=[];
for i=1:NumberOfNetworks
Results= [Results; FK(i) ];
end
Score= Results;
end```
**Tried the code above**

Related

Dividing a matrix into two parts

I am trying to classify my dataset. To do this, I will use the 4th column of my dataset. If the 4th column of the dataset is equal to 1, that row will added in new matrix called Q1. If the 4th column of the dataset is equal to 2, that row will be added to matrix Q2.
My code:
i = input('Enter a start row: ');
j = input('Enter a end row: ');
search = importfiledataset('search-queries-features.csv',i,j);
[n, p] = size(search);
if j>n
disp('Please enter a smaller number!');
end
for s = i:j
class_id = search(s,4);
if class_id == 1
Q1 = search(s,1:4)
elseif class_id ==2
Q2 = search(s,1:4)
end
end
This calculates the Q1 and Q2 matrices, but they all are 1x4 and when it gives new Q1 the old one is deleted. I need to add new row and make it 2x4 if conditions are true. I need to expand my Q1 matrix.
Briefly I am trying to divide my dataset into two parts using for loops and if statements.
Dataset:
I need outcome like:
Q1 = [30 64 1 1
30 62 3 1
30 65 0 1
31 59 2 1
31 65 4 1
33 58 10 1
33 60 0 1
34 58 30 1
34 60 1 1
34 61 10 1]
Q2 = [34 59 0 2
34 66 9 2]
How can I prevent my code from deleting previous rows of Q1 and Q2 and obtain the entire matrices?
The main problem in your calculation is that you overwrite Q1 and Q2 each loop iteration. Best solution: get rid of the loops and use logical indexing.
You can use logical indexing to quickly determine where a column is equal to 1 or 2:
search = [
30 64 1 1
30 62 3 1
30 65 0 1
31 59 2 1
31 65 4 1
33 58 10 1
33 60 0 1
34 59 0 2
34 66 9 2
34 58 30 1
34 60 1 1
34 61 10 1
];
Q1 = search(search(:,4)==1,:) % == compares each entry in the fourth column to 1
Q2 = search(search(:,4)==2,:)
Q1 =
30 64 1 1
30 62 3 1
30 65 0 1
31 59 2 1
31 65 4 1
33 58 10 1
33 60 0 1
34 58 30 1
34 60 1 1
34 61 10 1
Q2 =
34 59 0 2
34 66 9 2
Warning: Slow solution!
If you are hell bent on using loops, make sure to not overwrite your variables. Either extend them each iteration (which is very, very slow):
Q1=[];
Q2=[];
for ii = 1:size(search,1) % loop over all rows
if search(ii,4)==1
Q1 = [Q1;search(ii,:)];
end
if search(ii,4)==2
Q2 = [Q2;search(ii,:)];
end
end
MATLAB will put orange wiggles beneath Q1 and Q2, because it's a bad idea to grow arrays in-place. Alternatively, you can preallocate them as large as search and strip off the excess:
Q1 = zeros(size(search)); % Initialise to be as large as search
Q2 = zeros(size(search));
Q1kk = 1; % Intialiase counters
Q2kk = 1;
for ii = 1:size(search,1) % loop over all rows
if search(ii,4)==1
Q1(Q1kk,:) = search(ii,:); % store
Q1kk = Q1kk + 1; % Increase row counter
end
if search(ii,4)==2
Q2(Q2kk,:) = search(ii,:);
Q2kk = Q2kk + 1;
end
end
Q1 = Q1(1:Q1kk-1,:); % strip off excess rows
Q2 = Q2(1:Q2kk-1,:);
Another option using accumarray, if Q is your original matrix:
Q = accumarray(Q(:,4),1:size(Q,1),[],#(x){Q(x,:)});
You can access the result with Q{1} (for class_id = 1), Q{2} (for class_id = 2) and so on...

How to classify a matrix within a Matlab parfor loop?

I am looking to classify the values of a matrix. The following example works outside of a parfor loop, however it does not work when used within a parfor loop. What are my options to classify matrices, following the provided example, within a parfor loop?
% Sample data
Imag1 = [ 62 41 169 118 210;
133 158 96 149 110;
211 200 84 194 29;
209 16 15 146 28;
95 144 13 249 170];
% Perform the classification
Imag1(find(Imag1 <= 130)) = 4;
Imag1(find(Imag1 >= 150)) = 1;
Imag1(find(Imag1 > 140)) = 2;
Imag1(find(Imag1 > 130)) = 3;
Results in the following (outside parfor loop):
Imag1 =
62 41 169 118 210
133 158 96 149 110
211 200 84 194 29
209 16 15 146 28
95 144 13 249 170
Imag1 =
4 4 1 4 1
3 1 4 2 4
1 1 4 1 4
1 4 4 2 4
4 2 4 1 1
You can use another matrix to store the result.
Imag2 = zeros(size(Imag1));
% Perform the classification
Imag2(find(Imag1 <= 130)) = 4;
Imag2(find(Imag1 >= 150)) = 1;
Imag2(find(Imag1 > 140)) = 2;
Imag2(find(Imag1 > 130)) = 3;
so you can use a parfor loop somehow. Since parfor doesn't care about order of execution. Your code doesn't work in a parfor loop because right now you are modifying the values of Imag1, then comparing those values again, aka any loop iteration would be be dependent on the prior loop iterations
Here's another approach:
parfor c = 1:size(Imag1,2)
Imag2(:,c) = 4-min(ceil(max((Imag1(:,c) - 130),0)/10),3);
end
Now you can split it up however you like; by rows, by columns, by blocks, by alternate columns...
Edit:
Unfortunately this classifies a value of 150 as 2. So you probably shouldn't use this one.
Take 3
class = [150 141 131 0]; %// minimum values for class 1, 2, 3, 4
[m, n] = size(Imag1);
parfor c=1:n
for r=1:m
Imag3(r,c) = find(Imag1(r,c) >= class, 1);
end
end

Matlab - Create a vector using another vector as the limits

Say I have the following columns vector Z
1 53 55 57 60 64 68 70 71 72 74 76 77 78 79 80 255
I want to use it to create a matrix such that each row would contain all the number between (and including) 2 adjacent elements in Z
So the output matrix should be something like this:
1 2 3 .... 53
53 54 55
55 56 57
57 58 60
....
80 81 ... 255
I've been searching for something similar but couldn't find it.
Thanks
See if this works for you -
lens = diff(Z)+1;
mask1 = bsxfun(#le,[1:max(lens)]',lens); %//'
array1 = zeros(size(mask1));
array1(mask1) = sort([1:255 Z(2:end-1)]);
out = array1.'; %//'# out is the desired output
Try this to break the monotony of bsxfun :) :
d = diff(Z);
N = max(d)+1;
R = zeros(length(Z)-1,N);
for i = 1:length(Z)-1
R(i,1:1+d(i)) = Z(i):Z(i+1);
end
EDIT:
I know that the general consensus is that one always should try to avoid loops in Matlab, but is this valid for this example? I know that this is a broad question, so lets focus on this particular problem and compare bsxfun to JIT loop. Comparing the two proposed solutions:
the code used for testing:
Z = [1 53 55 57 60 64 68 70 71 72 74 76 77 78 79 80 255];
%[1 3 4, 6];
nn = round(logspace(1,4,10));
tm1_nn = zeros(length(nn),1);
tm2_nn = zeros(length(nn),1);
for o = 1:length(nn)
tm1 = zeros(nn(o),1);
tm2 = zeros(nn(o),1);
% approach1
for k = 1:nn(o)+1
tic
d = diff(Z);
N = max(d)+1;
R = zeros(length(Z)-1,N);
for i = 1:length(Z)-1
R(i,1:1+d(i)) = Z(i):Z(i+1);
end
tm1(k) = toc;
end
%approach 2
for k = 1:nn(o)+1
tic
lens = diff(Z)+1;
mask1 = bsxfun(#le,[1:max(lens)]',lens); %//'
array1 = zeros(size(mask1));
array1(mask1) = sort([1:255 Z(2:end-1)]);
out = array1.';
tm2(k) = toc;
end
tm1_nn(o) = mean(tm1);%sum(tm1);%mean(tm1);%
tm2_nn(o) = mean(tm2);%sum(tm2);%mean(tm2);%
end
semilogx(nn,tm1_nn, '-ro', nn,tm2_nn, '-bo')
legend('JIT loop', 'bsxfun')
xlabel('log_1_0(Number of runs)')
%ylabel('Sum execution time')
ylabel('Mean execution time')
grid on
I encountered other tasks previously where the loop was faster. (or I mess up the comparison?)

adding the values in a matrix based on the corresponding unique values of another matrix

e=[40 19 18 20 30 34 65 97 155 160];
If there is a minimum difference between two consecutive values (for e.g. (19,18), (30, 34) and (155,160)) then merge these values..
Similar values also...Whatever condition can be used to solve this..Kindly help to solve this..
Iteratively,
e = [ 40 19 18 20 30 34 65 97 155 160];
current = e + 1; % init
prev = e;
while ~isequal( current, prev )
prev = current;
d = [ diff( prev ) < 5 true]; % always keep the last one
current = prev( d );
end

Remove the minimum values per each column of a Matrix

If I had a matrix A such as:
63 55 85 21 71
80 65 85 48 53
55 60 93 71 66
21 65 40 33 21
61 90 80 48 50
... and so on how would I find the minimum values of each column and remove those numbers from the matrix completely, meaning essentially I would have one less row overall.
I though about using:
[C,I] = min(A);
A(I) = [];
but that wouldn't remove the necessary numbers, and also reshape would not work either. I would like for this to work with an arbitrary number of rows and columns.
A = [
63 55 85 21 71
80 65 85 48 53
55 60 93 71 66
21 65 40 33 21
61 90 80 48 50
];
B = zeros( size(A,1)-1, size(A,2));
for i=1:size(A,2)
x = A(:,i);
maxIndex = find(x==min(x(:)),1,'first');
x(maxIndex) = [];
B(:,i) = x;
end
disp(B);
Another vectorized solution:
M = mat2cell(A,5,ones(1,size(A,2)));
z = cellfun(#RemoveMin,M);
B = cell2mat(z);
disp(B);
function x = RemoveMin(x)
minIndex = find(x==min(x(:)),1,'first');
x(minIndex) = [];
x = {x};
end
Another solution:
[~,I] = min(A);
indexes = sub2ind(size(A),I,1:size(A,2));
B = A;
B(indexes) = [];
out = reshape(B,size(A)-[1 0]);
disp(out);
Personally I prefer the first because:
For loops aren't evil - many times they are actually faster (By using JIT optimizer)
The algorithm is clearer to the developer who reads your code.
But of course, its up to you.
Your original approach works if you convert the row indices resulting from min into linear indices:
[m, n] = size(A);
[~, row] = min(A,[],1);
A(row + (0:n-1)*m) = [];
A = reshape(A, m-1, n);