how to do this calculation not by 'for' cycle?
1 Ansicht (letzte 30 Tage)
Ältere Kommentare anzeigen
vx2008
am 15 Dez. 2015
Kommentiert: Guillaume
am 15 Dez. 2015
I have the below data:
data =[...
1.0000 1.0000 1.0000 53.1100;...
1.0000 2.0000 2.0000 59.0900;...
2.0000 1.0000 2.0000 71.3100;...
2.0000 2.0000 1.0000 70.2400]
Now I want to get a 'variable'--Data as below:
Data=[53.11+59.09 53.11+71.31 53.11+70.24;
71.31+70.24 59.09+70.24 59.09+71.31]
I can get 'Data' by 'for' cycle function but I want to do this work by other better method.
The addition logic is that:
take column 2 of data for example, both data(1,2) and data(3,2) equal 1.0000, so add data(1,4) and data(3,4) to get Data(1,2).
0 Kommentare
Akzeptierte Antwort
Guillaume
am 15 Dez. 2015
One possible way to do it:
data = [1 1 1 53.1100
1 2 2 59.0900
2 1 2 71.3100
2 2 1 70.2400];
%first split data into two matrices for easier referencing:
rowdest = data(:, 1:end-1);
rowvals = data(:, end);
%second create matrix of column indices
coldest = repmat(1:size(rowdest, 2), size(rowdest, 1), 1);
%third use accumarray to compute the sum:
newdata = accumarray([rowdest(:) coldest(:)], repmat(rowvals, size(rowdest, 2), 1))
0 Kommentare
Weitere Antworten (1)
Stephen23
am 15 Dez. 2015
Bearbeitet: Stephen23
am 15 Dez. 2015
inp = [1,1,1,53.1100;1,2,2,59.0900;2,1,2,71.3100;2,2,1,70.2400]
out(:,3) = accumarray(inp(:,3),inp(:,4));
out(:,2) = accumarray(inp(:,2),inp(:,4));
out(:,1) = accumarray(inp(:,1),inp(:,4))
and the result is:
out =
112.20 124.42 123.35
141.55 129.33 130.40
and your example output is:
>> [53.11+59.09,53.11+71.31,53.11+70.24;71.31+70.24,59.09+70.24,59.09+71.31]
ans =
112.20 124.42 123.35
141.55 129.33 130.40
1 Kommentar
Guillaume
am 15 Dez. 2015
If data is always three columns of indices + one column of number, this works. If the size of data is not fixed, my answer is more generic.
Siehe auch
Kategorien
Mehr zu Structures finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!