Quick way to sum array elements based on flag in another array?
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Say I have 2 arrays: one with "clean" data, and one that tells me which data gets lost, as indicated by zeros. If an element is lost, it should be added to the next observed element. Anybody got a quick one-or-two-liner to come up with the summed array?
Example:
clean = [1 2 3 4 5 6]
lost = [1 0 3 0 0 6]
desired = [1 5 15]
댓글 수: 1
채택된 답변
Stephen23
2015년 7월 14일
편집: Stephen23
2015년 7월 14일
Try this:
tmp = (1:numel(lost))-[0,cumsum(lost(1:end-1)==0)];
desired = accumarray(tmp.',clean).'
Tested:
>> clean = [1 2 3 4 5 6];
>> lost = [1 0 3 0 0 6];
>> tmp = (1:numel(lost))-[0,cumsum(lost(1:end-1)==0)];
>> desired = accumarray(tmp.',clean).'
desired =
1 5 15
>> clean = [40 10 50 30 40 10 50 30 40 10 50 30];
>> lost = [40 0 50 30 0 10 0 0 40 10 50 30];
>> tmp = (1:numel(lost))-[0,cumsum(lost(1:end-1)==0)];
>> desired = accumarray(tmp.',clean).'
desired =
40 60 30 50 120 10 50 30
추가 답변 (2개)
Andrei Bobrov
2015년 7월 14일
편집: Andrei Bobrov
2015년 7월 14일
desired = flip(accumarray(cumsum(lost(end:-1:1)~=0)',clean(end:-1:1)),1)';
or
desired = accumarray(cumsum(xor([0,diff(lost > 0)],lost))',clean)';
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