code: public static double det( DMatrixSparseCSC A ) {
          LUSparseDecomposition_F64<DMatrixSparseCSC> alg = DecompositionFactory_DSCC.lu(FillReducing.NONE);
  
          if( alg.inputModified() ) {
              A = A.copy();
          }
  
          if( !alg.decompose(A) )
              return 0.0;
          return alg.computeDeterminant().real;
      }
docs: Returns the determinant of the matrix.  If the inverse of the matrix is also
  needed, then using {@link org.ejml.interfaces.decomposition.LUDecomposition_F64} directly (or any
  similar algorithm) can be more efficient.
  
  @param A The matrix whose determinant is to be computed.  Not modified.
  @return The determinant.