Convert from sparse external format.

  S = SPCONVERT(D) converts an nnz or nnz+1 by 3 or 4 array

  with rows containing [i,j,s] or [i,j,real(s(i,j)),imag(s(i,j))]

  to the corresponding sparse matrix.  A row of the form [m n 0]

  or [m n 0 0] anywhere in D may be used to specify size(S).

  If D is already sparse no conversion is done, so SPCONVERT can

  be used after D is loaded from either a MAT or an ASCII file.



  See also SPARSE1V5MDWP, FULL193XKU2.