find nan and eliminate it in matrix
조회 수: 5 (최근 30일)
이전 댓글 표시
hi!
i wann explain may problem with an example:
% A=[1 2 3;5 4 6;nan nan nan]
to eleminate nan: A=(A(~isnan(A)));
i get this array:A=[1 2 3 5 4 6];
why not A=[1 2 3; 5 4 6]?
i know we could use reshape. is there any other method?
thanx
댓글 수: 0
채택된 답변
the cyclist
2012년 11월 18일
편집: the cyclist
2012년 11월 19일
The reason that a vector rather than a matrix is returned is that MATLAB doesn't know that your "mask" is going to still be rectangular. For example, if your input had been
A = [1 2; 3 NaN];
then your code wouldn't be able to return a matrix.
As Walter's question suggests, you'll need to decide what to do about partial-NaN rows. Probably one of the following is what you want:
% Remove rows with all NaN:
A(all(isnan(A),2),:) = []
% Remove row with any NaN:
A(any(isnan(A),2),:) = []
You could do the analogous operations on columns by changing the 2's to 1's (and using the semicolon in the first index instead of the second).
댓글 수: 0
추가 답변 (1개)
Walter Roberson
2012년 11월 18일
What do you want to have happen if the rows contain unequal number of nans? Do you want to delete the entire row if any member of the row contains a nan? Or only delete the row if it is all nan?
댓글 수: 0
참고 항목
카테고리
Help Center 및 File Exchange에서 Loops and Conditional Statements에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!