Table manipulation of matrix
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Hi
I want to a code that will compute group each c1/c2 for each column using K = to any number
Assuming I have n = numbers length
In my case I have 1,200 columns
And 1,200 rows
For instance, if K = 2
For each columns
The sum lowest c1 + c1 / the sum lowest c2 + c2
And it goes down the column for the next lowest c1 + c1/c2 + c2 till the end
If K = 3
Same the lowest c1 + c1 + c1/ the lowest c2 + c2 + c2
And it goes down the column for the next lowest c1 + c1 + c1/c2 + c2 + c2 till the end
I have been trying to work this out using the code below but but not getting it right. It is supposed to give me multiple answers for each column depending on K
c1 = sort(J(1:2:end,:));
size(c1)
c2 = sort(J(2:2:end,:));
size(c2
f = sum (c1(1: K, :));
size(f)
c = sum (c2(1: K,: ));
size(c)
s1 = (f/c);
for instance find the data below
A B C D E F G Class
1 1 1 0 1 1 1 c1
2 2 1 2 1 0 1 c2
1 1 1 1 2 1 1 c1
2 1 1 1 1 1 1 c2
2 2 0 0 0 0 0 c1
1 1 1 1 1 1 1 c2
1 1 1 1 1 1 1 c1
1 0 0 1 1 1 1 c2
Lets do column 1
First Sorting
1 c1
1 c1
1 c1
1 c2
1 c2
2 c1
2 c2
2 c2
K = 2
The lowest c1 + c1/ The lowest c2 + c2
For column A
1+1/1+1 = 2/2 = 1
The next lowest c1 + c1/The next lowest c2 + c2
1 + 2 / 2+2 = 3/2 = 1.5
So column 1 will be
1
1.5
Thanks for your help in advance
Tino
Find my code again
c1 = sort(J(1:2:end,:));
size(c1)
c2 = sort(J(2:2:end,:));
size(c2
f = sum (c1(1: K, :));
size(f)
c = sum (c2(1: K,: ));
size(c)
s1 = (f/c);
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Guillaume
2019년 5월 15일
편집: Guillaume
2019년 5월 15일
Your question is really badly explained but I think I've understood what you want.
My understanding is that you have a J matrix where the odd rows are labeled 1 and even rows labeled 2. For each column, you want to sum the sorted odd rows over a non-overlapping sliding window of length K and divide that by the corresponding sum over the sorted even rows.
If so:
%J: a matrix whose number of rows is a multiple of 2*K.
%K: an integer, the window size
assert(mod(size(J, 1) / 2, K) == 0, 'Height of J is not a multiple of 2*K')
result = zeros(size(J, 1) / 2 / K, size(J, 2)); %preallocate result
for col = 1:size(J, 2) %loop over the columns. You can't do this without a loop due to the requirement to sort each columns separately
result(:, col) = sum(reshape(sort(J(1:2:end, col)), K, []), 1) ./ sum(reshape(sort(J(2:2:end, col)), K, []), 1); %sort even/odd rows, reshape each into a Kx? matrix, sum across rows and divide the two sums
end
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Guillaume
2019년 5월 16일
You'd use findgroups or the older unique to identify the groups, then splitapply or the older accumarray to apply the processing to each group.
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