sparse function in MATLAB does the following:
S = sparse(i,j,v) generates a sparse matrix S from the triplets i, j, and v such that S(i(k),j(k)) = v(k). The max(i)-by-max(j) output matrix has space allotted for length(v) nonzero elements. sparse adds together elements in v that have duplicate subscripts in i and j. If the inputs i, j, and v are vectors or matrices, they must have the same number of elements. Alternatively, the argument v and/or one of the arguments i or j can be scalars.
I would like to have a fairly equivalent function in Mathematica. Has anyone tried to do this beforehand?