Error in for loop: Index exceeds matrix dimensions.
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Hi everyone! I need help with my code.I have a matrix (300x300) with some equal rows, and I need to eliminate the duplicate rows. I can't solve the error. Can anyone help me??Thank you very much!
Below I copy the part of the code with the error and a simplified example.
clear all
matrix_f=[1 2 3; 1 2 3; 4 5 6; 7 8 9; 7 8 9; 10 11 12];
for k=1:length(matrix_f(:,1))
if matrix_f(k,1)==matrix_f(k+1,1)
matrix_f(k+1,:)=[];
end
end
1 件のコメント
VBBV
2024 年 8 月 1 日
編集済み: VBBV
2024 年 8 月 1 日
@Me, you need to give the column dimension for the matrix in the for loop and use size function instead of length
clear all
matrix_f=[1 2 3; 1 2 3; 4 5 6; 7 8 9; 7 8 9; 10 11 12];
for k=1:size(matrix_f,2) % give the column dimension here
if isequal(matrix_f(k,:),matrix_f(k+1,:)) % use isequal function for check
matrix_f(k,:)=[]; % delete duplicate rows of numbers
end
end
matrix_f % result
採用された回答
Aquatris
2024 年 8 月 1 日
編集済み: Aquatris
2024 年 8 月 1 日
You have essentially made two mistakes:
- matrix_f only has 6 rows. You setup up your for loop such that k is 1 2 3 4 5 6 . When k is 6, you are trying to reach the 7th row of matrix_f, which does not exist. So your for loop should iterate from 1 to [length(matrix_f(:,1)-1].
- Within the for loop you change the size of matrix_f by removing rows. If you want to do this type of manipulation, you should just store the index you want to remove and remove the rows once your for loop is done. Otherwise indexing becomes messed up and you will run into the same issue, trying to reach a row that does not exist.
- You only remove rows that are next to each other.
clear all
matrix_f=[1 2 3; 1 2 3; 4 5 6; 7 8 9; 7 8 9; 10 11 12];
idx2remove = [];
for k=1:(length(matrix_f(:,1))-1)
if matrix_f(k,1)==matrix_f(k+1,1)
idx2remove = [idx2remove;k];
end
end
matrix_f(idx2remove,:) = [];
matrix_f
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