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

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!

[Birdman]

Can you give example with numeric arrays?

Answer 1

[Walter Roberson]

Example:

V = @(M) M(:);

sum( V( SomeArray(1:18, 5:43, :, 2:9) ) )

[Renat]

Awesome! Thanks! Apparently, I can even specify sum(M(:)), which will make it even easier!

Answer 2

[Pooja Lalan]

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] )

Answer 3

[Guillaume]

Not sure it is concise, it avoids the multiple sum:

sum(reshape(A(yourange), 1, []))

[Renat]

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.