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796    APPENDIX A A MAPLE Primer

                                    In an entirely analogous way, we can carry out vector operations in spherical coordinates.
                                 First, change to this coordinate system:
                                             SetCoordinates(‘spherical’[rho,theta,phi]);
                                    For the MAPLE command

                                                              ∗
                                                Gradient(rho sin(phi)∧2) cos(theta/2));
                                                                            ∗
                                 returns the gradient in spherical coordinates:

                                                                                          1
                                                    1       1     2    1       2sin(φ)cos  2  θ cos(φ)
                                              2
                                         sin(φ) cos  θ e ρ −  sin(φ) sin  θ e θ +                  e φ .
                                                    2       2          2               sin(θ)
                                    Some vector operations can also be carried out using the linear algebra package, which is
                                 discussed next. Details are available in the MAPLE Help package.


                     A.4         Matrix Manipulations

                                 To work with matrices, load the linear algebra package, using

                                                               with(linalg);
                                 Again, the semicolon will give a list of the subroutines. To avoid the list, end this command with
                                 a colon.
                                    There are many ways to enter a matrix. One way is to enter the dimension and the rows. For
                                 example,

                                              Matrix(4,2,[[-1,3],[6,1],[6,5],[-1,-2]]);
                                 enters the 4 × 2matrix
                                                                 ⎛        ⎞
                                                                   −1   3
                                                                    6   1
                                                                 ⎜        ⎟
                                                                 ⎜        ⎟ .
                                                                 ⎝ 6
                                                                        5 ⎠
                                                                   −1 −2
                                    To give this matrix the name K, enter
                                             K:=Matrix(4,2,[[-1,3],[6,1],[6,5],[-1,-2]]);
                                    For the inverse of a nonsingular matrix A which has been entered, use

                                                                inverse(A);
                                    For the rank of a matrix L (which need not be square), use
                                                                  rank(L);
                                    For the determinant of square A, use

                                                                   det(A);
                                    Multiply a matrix A by a scalar c by
                                                                      ∗
                                                                     c A;
                                    Add two n × m matrices as we would expect using
                                                                   A+B;




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                                   October 14, 2010  15:43  THM/NEIL   Page-796        27410_24_appA_p789-800
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