ho to find index at which the 50% of the sum vector is included?

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benghenia aek
benghenia aek 2021-11-26
回答： Image Analyst 2021-11-27
ho to find index at which the 50% of the sum vector is included?
a=[3 5 7 3 5 8 9 3 1 41 6];
sum(a)=91
50% of sum signal =45.5
indice which is approximately equal to of sum of 50% of sum signal a is 9

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回答（2 个）

Star Strider
Star Strider 2021-11-26
Ran in:
A least-squared-difference approach works —
a=[3 5 7 3 5 8 9 3 1 41 6];
suma = cumsum(a);
suma50 = suma(end)/2;
[minv,idxv] = min((suma50-suma).^2)
minv = 2.2500
idxv = 9
.
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Star Strider
Star Strider 2021-11-26
My pleasure!
If my Answer helped you solve your problem, please Accept it!
.
Steven Lord
Steven Lord 2021-11-26
Ran in:
If you want the first index that's past the halfway point:
a=[3 5 7 3 5 8 9 3 1 41 6];
suma = cumsum(a)
suma = 1×11
3 8 15 18 23 31 40 43 44 85 91
suma50 = suma(end)/2
suma50 = 45.5000
[~, location] = find(suma > suma50, 1, 'first')
location = 10
suma([location-1 location])
ans = 1×2
44 85

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Image Analyst
Image Analyst 2021-11-27
Ran in:
Isn't this a duplicate?
If it's not your homework, you can use my solution:
a = [3 5 7 3 5 8 9 3 1 41 6];
s = sum(a)
s = 91
c = cumsum(a)
c = 1×11
3 8 15 18 23 31 40 43 44 85 91
[minDiff, index] = min(abs(c - s/2))
minDiff = 1.5000
index = 9
(If it is your homework, tag it as homework and find a different way. Don't turn in any of our solutions as your own or you may get caught for cheating.)

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