Sparse Matrix

 Hello There (and good Morning)


 I'm having some problems with the Matrix-Matrix multiplication when they
 are sparse matrices. It seems to be that when multiplying the matrix
 tends to lose dispersion... I suppose it makes a dot product between the rows
 and columns and the accumulator finishes with zero, but the algorithm puts
 that zero in the matrix and I think it should not put anything at all, should 

 it? (I'm having the same problem with the Matrix-Vector multiplication)

 Is there any way to fix this problem? (I perform a serie of multiplications
                                        to the same matrix and it would be 
                                        very useful)
 
  And.... I'm very clumsy reading the documentation and couldn't find
  any way to set the value of the position of a (sparse) Vector/Matrix 
  to zero, I mean.. if I try Vector(i)=0; (when Vector(i)==3, for 
  example ) it doesn't reduce the number of non zero elements. 
  Isn't there something like Vector.clear(i) ?



  Thank you very much for everything.
 
 

  Leandro Franco Londoño
  Ing. de Sistemas y Computación
  Universidad de los Andes
  Bogota
  Colombia

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