Returns the (multiplicative) inverse of invertible `self`. Parameters ---------- None Returns ------- ret : matrix object If `self` is non-singular, `ret` is such that ``ret * self`` == ``self * ret`` == ``np.matrix(n
(self)
| 792 | |
| 793 | @property |
| 794 | def I(self): |
| 795 | """ |
| 796 | Returns the (multiplicative) inverse of invertible `self`. |
| 797 | |
| 798 | Parameters |
| 799 | ---------- |
| 800 | None |
| 801 | |
| 802 | Returns |
| 803 | ------- |
| 804 | ret : matrix object |
| 805 | If `self` is non-singular, `ret` is such that ``ret * self`` == |
| 806 | ``self * ret`` == ``np.matrix(np.eye(self[0,:].size))`` all return |
| 807 | ``True``. |
| 808 | |
| 809 | Raises |
| 810 | ------ |
| 811 | numpy.linalg.LinAlgError: Singular matrix |
| 812 | If `self` is singular. |
| 813 | |
| 814 | See Also |
| 815 | -------- |
| 816 | linalg.inv |
| 817 | |
| 818 | Examples |
| 819 | -------- |
| 820 | >>> m = np.matrix('[1, 2; 3, 4]'); m |
| 821 | matrix([[1, 2], |
| 822 | [3, 4]]) |
| 823 | >>> m.getI() |
| 824 | matrix([[-2. , 1. ], |
| 825 | [ 1.5, -0.5]]) |
| 826 | >>> m.getI() * m |
| 827 | matrix([[ 1., 0.], # may vary |
| 828 | [ 0., 1.]]) |
| 829 | |
| 830 | """ |
| 831 | M, N = self.shape |
| 832 | if M == N: |
| 833 | from numpy.linalg import inv as func |
| 834 | else: |
| 835 | from numpy.linalg import pinv as func |
| 836 | return asmatrix(func(self)) |
| 837 | |
| 838 | @property |
| 839 | def A(self): |