Subtracting elements with constraints
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Hi all,
I have an array A and I need to subtract the elements of each column using the cumsum function:
B=bsxfun(@minus, A(1,:), cumsum(A(2:end,:)));
However I have some constraints that should not violated (min=1.3, max=11.7) Is there any way to do the calculations within these limits?
thanks
3 个评论
Walter Roberson
2017-2-27
What should happen if it goes outside that range? And since the items might be positive or negative, it could potentially go back into the range again.
Nikolas Spiliopoulos
2017-2-27
采纳的回答
Your question is not clear where you want these constraints applied.
Option one: constrain output values:
B = bsxfun(@minus, A(1,:), cumsum(A(2:end,:)));
B = max(1.3, min(11.7, B));
Options two: constrain cumsum values:
tmp = max(1.3, min(11.7, cumsum(A(2:end,:))));
B = bsxfun(@minus, A(1,:), tmp);
3 个评论
Guillaume
2017-2-27
And note that if you're using R2016b, the bsxfun is not needed
BorTMP = A(1, :) - cumsum(A(2:end, :)); %in R2016b
Walter Roberson
2017-2-27
Another possibility: that at each point the sum needs to be in that range, and if adding the next element would move it out of the range then clamp it at the edge of the range, but allow the next element to move it away from the edge of the range. For example, if the lower limit was 1, then for
A = 6 2 2 2 2 -3
cummulative
C = 4 2 1 1 4
^ ^
the clamping has been applied at the ^ points, but no history of how far outside the range it would go, so the -(-3) moves it 3 away from the bottom of the range
I am not sure at the moment that a vectorized version of this approach is possible.
Nikolas Spiliopoulos
2017-2-27
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