how to specify time and months for year long data ?

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[Andrei Bobrov]

Please attach your data file

Answer 1

[Andrei Bobrov]

Let data - your array first column - 'year', second - 'month' ... fifth - 'temp'

[de, ~,c] = unique(data(:,1:2),'rows');
out2 = accumarray(c,data(:,5),[],@(x){[mean(x),min(x),max(x)]});
out = [de, cat(1,out2{:})];

for your array from seattle_tdry.txt only:

f = fopen('seattle_tdry.txt'); c = textscan(f,'%f %f %f %f'); fclose(f);
out2 = accumarray(c{1},c{4},[],@(x){[mean(x),min(x),max(x)]});
out = [unique(c{1}), cat(1,out2{:})];

[Andrei Bobrov]

Asked by Tom:

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From the weather file I need to work out the monthly average minimum and maximum temperatures. Taking the minimum daily values to get a minimum monthly average, and taking the maximum daily values to get a maximum monthly average.

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My answer:

f = fopen('seattle_tdry.txt'); 
c = textscan(f,repmat('%f ',1,4),'collectoutput',1); 
fclose(f);

[v1,~,cdaily] = unique(c{:}(:,1:2),'rows');
d1 = accumarray(cdaily,c{:}(:,end),[],@(x){[min(x), max(x)]});
d2 = cat(1,d1{:});
[x,y] = ndgrid(v1(:,1),1:2);
out = [unique(x(:,1)),accumarray([x(:),y(:)],d2(:),[],@mean)];