Matlab: fast way to sum ones in binary numbers with Sparse structure?

Question

Most answers only address the already-answered question about Hamming weights but ignore the point about find and dealing with the sparsity. Apparently the

Answer 1

This gives you the rowsums of the binary numbers from the sparse structure.

>> mlf=sparse([],[],[],2^31+1,1);mlf(1)=10;mlf(10)=111;mlf(77)=1010;  
>> transpose(dec2bin(find(mlf)))

ans =

001
000
000
011
001
010
101

>> sum(ismember(transpose(dec2bin(find(mlf))),'1'),2)

ans =

     1
     0
     0
     2
     1
     1
     2

Hope someone able to find faster rowsummation!