How to perform a single Matrix calculation and store result back into a vector or matrix

Question

Amishi 2011-10-23

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/19066-how-to-perform-a-single-matrix-calculation-and-store-result-back-into-a-vector-or-matrix

Hi, Everyone

I have written a code which calculates weighted distance in a single matrix. (similar to euclidean distance). I need to know how to store my results back into a matrix or vector instead of displaying it n times.

Here is my code

///////////////////////////

i=1; 
j=2; 
for i=1:4
for j=2:5
      if((i~=j)&&(i<j))
  d=0;    
       for k=1:6
       sum=(data(j,k)-data(i,k))^2;
       d=d+sum;
            end
d=(0.25*d)^(1/2)
       end       
  end
  ////////////////////
  end

For example if I have a 5x6 matrix as given below

92 45 27 31 0
64 59 32 23 0
54 33 16 54 0
78 34 24 36 0
70 12 28 10 0

my results are displayed as

d =
16.3478
d =
23.6590
d =
9.8362
d =
22.4666
d =
22.3271
d =
16.5076
d =
24.6678
d =
15.7321
d =
26.3534
d =
17.7200

But I would like to store as

d=[ 16.3478; 23.6590; 9.8362; 22.4666; 22.3271; 16.5076; 24.6678; 15.7321; 26.3534; 17.7200]

Please If anyone could help me.

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Walter Roberson 2011-10-23

The line

////////////////////

is not valid in your code, and would cause your code to fail.

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Answer 1

Fangjun Jiang 2011-10-23

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/19066-how-to-perform-a-single-matrix-calculation-and-store-result-back-into-a-vector-or-matrix#answer_25477

在 MATLAB Online 中打开

"i=1; j=2;" is not needed based on your code.
Don't use "sum" as the variable name. sum() is a built-in function.

Your code can be improved as the following:

data=rand(5,6);
[M,N]=size(data);
d=zeros(M*(M-1)/2,1);
count=0;
for i=1:M-1
    for j=2:M
        if((i~=j)&&(i<j))
            count=count+1;    
            for k=1:N
                d(count)=d(count)+(data(j,k)-data(i,k))^2;
            end
            d(count)=(0.25*d(count))^(1/2);
        end       
    end
end