How do I sum over multiple dimensions? I want my final result to be a average with respect to area not the number of grids.

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Nesha Wright 2018-6-20

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评论： Nesha Wright 2018-6-20

When I use the sum command it sums the rows (A=sum(b)). I want a global average (emissions/space) as my final value and I keep getting a massive array. I need the sum of the first array divided by the sum of the second array. The first array is 4D.

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Answer 1

Image Analyst 2018-6-20

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在 MATLAB Online 中打开

"I need the sum of the first array divided by the sum of the second array."

Try this:

ratio = sum(array4D(:)) / sum(otherArray(:));

None of us have any idea what you're talking about when you talk about grids, but you might check out the FAQ: https://matlab.wikia.com/wiki/FAQ#How_do_I_split_an_image_into_non-overlapping_blocks.3F or see the attached demos.

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Answer 2

Guillaume 2018-6-20

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在 MATLAB Online 中打开

mean(yourarray(:))

No need to use sum to calculate the mean.

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Guillaume 2018-6-20

What grid squares?

I need to divide by ...

Need to divide what?

Nesha Wright 2018-6-20

When the command mean is used on a gridded dataset it takes the sum of the array and divides it by the number of grid cell, I need to divide it by the sum area of the grid cells, not how many there are. I could be wrong...

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