Splitapply command and merge results

2021 7 26
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更新时间：2021 7 27
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In general I am using this command "splitapply" in order to find mean (average) of a group of data.
edges=1:0.5:10
[N, edges, bin] = histcounts(B, edges);
mean_B=splitapply(@mean, B, bin) %mean
%B is 100x1 double
But I would like to make a code that will :
1) Group my data into bins from edges : 1:0.5:10 (min=1, max=10 with step equal to 0.5)
2) Compute the means of the values in each bin (lets call it set1).
3) Group my data into bins from edges : 2:1:10 (min=2, max=10 with step equal to 1)
4) Compute the means of the values in each bin (set2).
5) Merge two sets of data
Could you please help me in order to make it?
Thanking you in advance

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回答（1 个）

Rik
Rik 2021-7-26
Ran in:

0 个投票

Ran in:
The question for you is what you mean by merging, but steps 1 to 4 are below.
%generate example data
B=10*rand(1,100);
edges1=[1 0.5 10];
edges2=[2 1 10];
mean_B_set1=mean_group_data(B,edges1)
mean_B_set1 = 1×18
1.1522 1.6931 2.2359 2.7160 3.2395 3.8087 4.3454 4.7591 5.2552 5.7937 6.2050 6.7348 7.2927 7.6282 8.2723 8.7246 9.2756 9.7841
mean_B_set2=mean_group_data(B,edges2)
mean_B_set2 = 1×8
2.5560 3.3270 4.5522 5.6142 6.4405 7.5062 8.4984 9.5299
function mean_B=mean_group_data(B,msm)
B(B<msm(1) | B>msm(3))=[];%remove data outside of bounds
edges=msm(1):msm(2):msm(3);
[~, ~, bin] = histcounts(B, edges);
mean_B=splitapply(@mean, B, bin);
if numel(mean_B)<(numel(edges)-1)
mean_B((end+1):(numel(edges)-1))=NaN;%extend to fill all bins
end
end

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Ivan Mich
Ivan Mich 2021-7-27
Look for example from the first set I will have 5 bins with 5 mean numbers. From the second set I will have 4 bins with 4 mean numbers. every mean number corresponds to one bin . I am giving you an example of the output
set 1
Bin mean
[2-3] 0.5
[3-4] 1.25
[4-5] 1.6
[5-6] 1.9
[6-7] 3.2
set 2
Bin mean
[2.5-3.5] 0.75
[3.5-4.5] 1
[4.5-5.5] 1.7
[5.5-6.5]2.5
So I mean merge to have an output that will includes all the values.
Like
mean
0.5
0.75
1
1.6
1.7
1.9
2.5
3.2
That's what I mean.
Could you please help me?
Rik
Rik 2021-7-27
That is almost clear. However, your output has 8 numbers, while you started out with 4+5 numbers.
Do you just want to put the all in a vector and sort them, or do you want first a value from set 1, then a value from set 2, then the next from set 1, and so on?
Ivan Mich
Ivan Mich 2021-7-27
编辑：Ivan Mich 2021-7-27
Excuse me my final output is :
0.5
0.75
1
1.25
1.6
1.7
1.9
2.5
3.2
that corresponds to bins
[2-3]
[2.5-3.5]
[3-4]
[3.5-4.5]
[4-5]
[4.5-5.5]
[5-6]
[5.5-6.5]
[6-7]
Rik
Rik 2021-7-27
Ran in:
Ran in:
Your desired output will be the third column of the array below.
edges1=[2 1 7 ];
edges2=[2.5 1 6.5];
mean_B_set1=[0.5;1.25;1.6;1.9;3.2];
mean_B_set2=[0.75;1;1.7;2.5];
e1=edges1(1):edges1(2):edges1(3);
e2=edges2(1):edges2(2):edges2(3);
%col 1 contains bin starts, col 2 contains bin ends
%col 3 contains the sets
tmp=[e1(1:(end-1)).' e1(2:end).' mean_B_set1;...
e2(1:(end-1)).' e2(2:end).' mean_B_set2];
output=sortrows(tmp)
output = 9×3
2.0000 3.0000 0.5000 2.5000 3.5000 0.7500 3.0000 4.0000 1.2500 3.5000 4.5000 1.0000 4.0000 5.0000 1.6000 4.5000 5.5000 1.7000 5.0000 6.0000 1.9000 5.5000 6.5000 2.5000 6.0000 7.0000 3.2000

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Ivan Mich
Ivan Mich
2021-7-26

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Rik
Rik
2021-7-27

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