docs: public DMatrixSparseCSC apply( DMatrixSparseCSC A ) {
          if( fillReduce == null )
              return A;
          fillReduce.process(A);
  
          IGrowArray gp = fillReduce.getRow();
  
          if( pinv.length < gp.length)
              pinv = new int[ gp.length ];
          CommonOps_DSCC.permutationInverse(gp.data, pinv, gp.length);
          if( symmetric )
              CommonOps_DSCC.permuteSymmetric(A, pinv, Aperm, gw);
          else
              CommonOps_DSCC.permuteRowInv(pinv, A ,Aperm);
          return Aperm;
      }