Is there a concise way of summing over multiple dimensions of an array?

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Renat
Renat 2017-12-4
编辑： Pooja Lalan 2018-11-7
Hello all,
Is there a concise way of summing over multiple dimensions, i.e. using just one sum function? I know if I have a defined array A, then I can do:
sum(A(:));
But what if I want to sum over a range of that array or some kind of calculated array? I would either have to use sum of sum of sum and so on to get the total sum or assign a variable to that temporary array? Thank you!

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采纳的回答

Walter Roberson
Walter Roberson 2017-12-4
Example:
V = @(M) M(:);
sum( V( SomeArray(1:18, 5:43, :, 2:9) ) )

更多回答（2 个）

Pooja Lalan
Pooja Lalan 2018-11-7
编辑：Pooja Lalan 2018-11-7
Starting in R2018b, you can use this syntax
sum( SomeArray(1:18, 5:43, :, 2:9), 'all' )
Or the 'vector of dimensions' input argument :
sum( SomeArray(1:18, 5:43, :, 2:9), [1 2 3 4] )
Guillaume
Guillaume 2017-12-4
Not sure it is concise, it avoids the multiple sum:
sum(reshape(A(yourange), 1, []))
  1 个评论
Renat
Renat 2017-12-4
I thought about that, but I erroneously thought I would need to use numel in there to specify the new shape. One more new thing I learned today about Matlab.

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