Stuck in endless loop
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Hi all,
I am learning matlab thru practice and patience. I am trying to create a loop to get the mean of a precipitation dataset with a 0.5 grid spacing and dimensions x=141, y=71 and t =38. I am trying to build a structure to get the means per grid over each layer (38). I am running the following code but matlab is stuck in a endless loop. Is there any way to fix this to avoid getting stuck? Thanks in advance for your help
for t=1:38
for x=1:141
for y=1:71
meanprecip(y,x,t)=nanmean(rain(y,x,t))
end
end
end
6 个评论
Geoff Hayes
2019-10-24
Emmanuel - the code is probably not getting stuck in an endless loop since your for loops are well defined. The problem could be that the code is just slow. Try pre-sizing your meanprecip array since you know the dimensions of it:
meanprecip = zeros(38,141,71);
for t=1:38
% etc.
end
You may be able to optimize your code and remove some one (or more?) loops. I haven't downloaded your rain data, but what does rain(y,x,t) return? Is it a scalar or an array? If a scalar, what does nanmean do for this single value?
desert_scientist90
2019-10-24
Geoff Hayes
2019-10-24
So is rain(y,x,t) a scalar? I think it might be and so your first layer is rain(:,:,1), a 71x141 2D array. Do you really want to calculate the nanmean of this 2D array? Or a row or column?
desert_scientist90
2019-10-24
Geoff Hayes
2019-10-24
So if it is a scalar, then you are not calculating the mean over a set of years...just a single value. Which dimension represents years?
desert_scientist90
2019-10-24
回答（1 个）
Siriniharika Katukam
2019-10-29
编辑：Siriniharika Katukam
2019-10-29
Hi,
As per my understanding, you are trying to find the mean of grid at each layer. In your case, if the output of rain(y,x,t) is a scalar, then calculating mean of a scalar is like reassigning. It is similar to
meanprecip(y,x,t) = rain(y,x,t);
If you want to calculate the mean of the grid at each year,
Try this:
for t=1:38
meanprecip(t) = mean(rain(:,:,t))
end
Moreover, your code is not an endless loop.
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2019-10-24
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