Pick up values in vector by a threshold

Question

I have a vector

E = [ 2.91082 , 0.14735, 0.92122, 0.02061 ]

Now, I set the threshold T=0.95 which means that

T = ( 2.91082 + 0.92122)/(2.91082 + 0.14735 + 0.92122 + 0.02061 )=0.958>0.95

And then, I can pick up E[1] and E[3] as selected values.

Could you please tell me how can I do that ?

Answer 1

Use bsxfun for a vectorized solution -

[R,C] = find(triu(bsxfun(@plus,E,E.')./sum(E),1) > 0.95)

Sample run -

>> E = [ 2.91082 , 0.14735, 0.92122, 0.02061 ];
>> triu(bsxfun(@plus,E,E.')./sum(E),1) '%// T values
ans =
            0      0.76454      0.95801      0.73286
            0            0      0.26714      0.04199
            0            0            0      0.23546
            0            0            0            0
>> [R,C] = find(triu(bsxfun(@plus,E,E.')./sum(E),1) > 0.95)
R =
     1
C =
     3