how to order a matrix?

Question

Sky Scrapper 2018-11-30

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/433020-how-to-order-a-matrix

评论： Sky Scrapper 2018-12-3

采纳的回答： Andrei Bobrov

hi,

Say, I have a matrix,

A B C D

-6760,691 0 -1 0

-3380,495 1 -1 1

-6760,691 0 -1 0

-3380,395 -1 0 -1

-6760,691 0 -1 0

-3380,495 -1 -1 1

-6760,691 0 -1 0

-3380,395 -1 0 -1

3380,195 1 0 1

And I want to get,

A B C D

-6760,691 0 -1 0

-3380,495 1 -1 1

-1 -1 1

-3380.395 -1 0 -1

3380,195 1 0 1

Here, I need to order the unique values of A which is done on the 1st column. I'll have to write the different patterns of B, C, D on the basis of same value of A. And, if there is any more repeated values of B,C,D for the same value of A, i'll have to keep only 1 pattern (row).

Can anyone please help me?

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Answer 1

Andrei Bobrov 2018-11-30

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/433020-how-to-order-a-matrix#answer_349818

编辑：Andrei Bobrov 2018-12-1

在 MATLAB Online 中打开

EDIT

>> B = [-3380.5            1           -1            1
      -6760.7            0           -1            0
      -3380.4           -1            0           -1
      -3380.4           -1            0           -1
      -6760.7            0           -1            0
      -3380.5           -1           -1            1
      -6760.7            0           -1            0
      -3380.4           -1            0           -1
       3380.2            1            0            1];
>> A = unique(B,'rows')
A =
      -6760.7            0           -1            0
      -3380.5           -1           -1            1
      -3380.5            1           -1            1
      -3380.4           -1            0           -1
       3380.2            1            0            1
>> A([false;diff(A(:,1)) == 0],1) = nan
A =
      -6760.7            0           -1            0
      -3380.5           -1           -1            1
          NaN            1           -1            1
      -3380.4           -1            0           -1
       3380.2            1            0            1
>>  
       

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Sky Scrapper 2018-12-3

when i am working on my original matrix considering more columns say,

[ -3380.5 1 -1 1 0 0 0 0

-6760.7 0 -1 0 0 1 0 0

-3380.4 -1 0 -1 0 1 1 0

-3380.4 -1 0 -1 1 0 0 0

-6760.7 0 -1 0 0 0 1 0

-3380.5 -1 -1 1 1 0 1 0

-6760.7 0 -1 0 1 0 1 1

-3380.4 -1 0 -1 0 0 0 1

3380.2 1 0 1 0 1 0 1];

in this case, all rows are unique. But i would like to get,

-6760.7 0 -1 0 0 1 0 0

-3380.5 -1 -1 1 1 0 1 0

NaN 1 -1 1 0 0 0 0

-3380.4 -1 0 -1 0 1 1 0

3380.2 1 0 1 0 1 0 1

look, I would like to order unique states on the basis of 1st four column but they will take their corresponding whole rows.

Could you please solve this?

Andrei Bobrov 2018-12-3

A = [      -3380.5            1           -1            1       0     0    0      0
-6760.7            0           -1            0        0     1    0      0
-3380.4           -1            0           -1        0     1    1      0
-3380.4           -1            0           -1        1      0    0     0
-6760.7            0           -1            0         0     0    1     0
-3380.5           -1           -1            1         1     0    1     0
-6760.7            0           -1            0          1    0     1    1
-3380.4           -1            0           -1          0    0    0     1
3380.2            1            0            1           0    1    0     1];
[~,b] = unique(A(:,1:4),'rows');
B = A(b,:);
B([false;diff(B(:,1))==0],1) = nan;