How to fill arrays third column by matching first 2 columns

Question

sastra university 2022-10-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1830458-how-to-fill-arrays-third-column-by-matching-first-2-columns

评论： sastra university 2022-10-19

采纳的回答： KSSV

Dear all,

I have 2 arrays namely A & B.

A is 30 x 3 array with 3rd column zero.

B is 15 x 3 array with the result value in the 3rd column.

I want to fill the 3rd column of A by matching the first 2 columns with B.

for example,

A=[1 5 0;

1 12 0;

4 5 0;

4 9 0;

7 8 0;

8 2 0;

9 13 0];

B = [1 5 2740;

1 12 10;

8 2 1500;

7 8 750];

I want to get the array A's 3rd column filled with the values by comparing B.

results like,

A = [1 5 2740;

1 12 10;

4 5 0;

4 9 0;

7 8 750;

8 2 1500;

9 13 0];

Please suggest me a code for doing this for the larger size of array.

Thank you in advance.

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Answer 1

KSSV 2022-10-19

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1830458-how-to-fill-arrays-third-column-by-matching-first-2-columns#answer_1078658

在 MATLAB Online 中打开

A=[1           5           0;
      1          12           0;
      4           5           0;
      4           9           0;
      7           8           0;
      8           2           0;
      9          13           0];
B = [1           5        2740;
        1          12          10;
        8          2        1500;
        7           8         750];
F = scatteredInterpolant(B(:,1),B(:,2),B(:,3)) ;
A(:,3) = F(A(:,1),A(:,2)) ;
A
A = 7×3
1.0e+03 *

    0.0010    0.0050    2.7400
    0.0010    0.0120    0.0100
    0.0040    0.0050    1.9946
    0.0040    0.0090    0.7700
    0.0070    0.0080    0.7500
    0.0080    0.0020    1.5000
    0.0090    0.0130   -0.8471

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KSSV 2022-10-19

在 MATLAB Online 中打开

A=[1           5           0;
      1          12           0;
      4           5           0;
      4           9           0;
      7           8           0;
      8           2           0;
      9          13           0];
B = [1           5        2740;
        1          12          10;
        8          2        1500;
        7           8         750];
[c,ia] = ismember(B(:,1:2),A(:,1:2),'rows','legacy') ;
A(ia,3) = B(:,3)
A = 7×3
           1           5        2740
           1          12          10
           4           5           0
           4           9           0
           7           8         750
           8           2        1500
           9          13           0