sparse http://es.mathworks.com/help/matlab/ref/sparse.html来救援!
让您的数据和所需范围定义为
A = [ 205 204 201
202 208 202 ]; %// data. Two-row matrix
limits = [200 208]; %// desired range. It needn't include all values of A
Then
lim1 = limits(1)-1;
s = limits(2)-lim1;
cols = all((A>=limits(1)) & (A<=limits(2)), 1);
B = sort(A(:,cols), 1, 'descend')-lim1;
R = full(sparse(B(2,:), B(1,:), 1, s, s));
gives
R =
0 0 0 0 0 0 0 0 0
0 0 1 0 0 0 0 0 0
0 0 0 0 0 1 0 0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 1
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
或者,您可以省去sort
并使用矩阵加法,然后triu
获得相同的结果(可能更快):
lim1 = limits(1)-1;
s = limits(2)-lim1;
cols = all( (A>=limits(1)) & (A<=limits(2)) , 1);
R = full(sparse(A(2,cols)-lim1, A(1,cols)-lim1, 1, s, s));
R = triu(R + R.');
两种方法都处理重复的列(直到排序),正确地增加它们的计数。例如,
A = [205 204 201
201 208 205]
gives
R =
0 0 0 0 0 0 0 0 0
0 0 0 0 0 2 0 0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 1
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0