How do you get a global average at each time step so they can be summed?

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Nesha Wright 2018-6-23

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回答： Ameer Hamza 2018-6-25

I have a 4D array of emissions. I want the average emissions at each time step so that I can then sum all of these averages and determine the total emissions by a certain year (in this case the entire file).

I think that I need to use a loop but am not sure how. I am currently using this: mean_time=sum(squeeze(mean(mean(mean(total,1),2),3))); as time is the 4th dimension.

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Ameer Hamza 2018-6-23

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What do you think is wrong with this, it is better to use vectorized code instead of using for loop. Also the above is equivalent to

mean_time = sum(mean(mean(mean(total))));

Nesha Wright 2018-6-25

The only problem I was seeing was that I couldn't get a specific time from this which I think is just throwing my logic off. For example, if I wanted timestep 5 rather than the sum of the entire thing.

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Answer 1

Ameer Hamza 2018-6-25

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If you want to average at each time step as by omitting the sum() function. For example

averageTimeSteps = mean(mean(mean(total)));

if total is a 4D matrix, the above command will produce a 1D vector. You can access element just as a regular vector e.g. averageTimeSteps(1), averageTimeSteps(2), ... etc. However, the result is still a 4D matrix so display might be a bit confusing. To simplify the display, try

averageTimeSteps = squeeze(mean(mean(mean(total))));