Returns the square identity matrix of given size. Parameters ---------- n : int Size of the returned identity matrix. dtype : data-type, optional Data-type of the output. Defaults to ``float``. Returns ------- out : matrix `n` x `n` matrix w
(n,dtype=None)
| 149 | return a |
| 150 | |
| 151 | def identity(n,dtype=None): |
| 152 | """ |
| 153 | Returns the square identity matrix of given size. |
| 154 | |
| 155 | Parameters |
| 156 | ---------- |
| 157 | n : int |
| 158 | Size of the returned identity matrix. |
| 159 | dtype : data-type, optional |
| 160 | Data-type of the output. Defaults to ``float``. |
| 161 | |
| 162 | Returns |
| 163 | ------- |
| 164 | out : matrix |
| 165 | `n` x `n` matrix with its main diagonal set to one, |
| 166 | and all other elements zero. |
| 167 | |
| 168 | See Also |
| 169 | -------- |
| 170 | numpy.identity : Equivalent array function. |
| 171 | matlib.eye : More general matrix identity function. |
| 172 | |
| 173 | Examples |
| 174 | -------- |
| 175 | >>> import numpy.matlib |
| 176 | >>> np.matlib.identity(3, dtype=int) |
| 177 | matrix([[1, 0, 0], |
| 178 | [0, 1, 0], |
| 179 | [0, 0, 1]]) |
| 180 | |
| 181 | """ |
| 182 | a = array([1]+n*[0], dtype=dtype) |
| 183 | b = empty((n, n), dtype=dtype) |
| 184 | b.flat = a |
| 185 | return b |
| 186 | |
| 187 | def eye(n,M=None, k=0, dtype=float, order='C'): |
| 188 | """ |