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numpy array operationIs there a numpy operation that does the following to the array?
1 2 ==> 4 3 3 4 2 1 Thanks in advance. |

Re: numpy array operationC. Ng wrote:
> Is there a numpy operation that does the following to the array? > > 1 2 ==> 4 3 > 3 4 2 1 How about >>> a array([[1, 2], [3, 4]]) >>> a[::-1].transpose()[::-1].transpose() array([[4, 3], [2, 1]]) Or did you mean >>> a.reshape((4,))[::-1].reshape((2,2)) array([[4, 3], [2, 1]]) Or even >>> -a + 5 array([[4, 3], [2, 1]]) |

Re: numpy array operationOn Tuesday, January 29, 2013 3:41:54 AM UTC-5, C. Ng wrote:
> Is there a numpy operation that does the following to the array? > > > > 1 2 ==> 4 3 > > 3 4 2 1 > > > > Thanks in advance. >>> import numpy as np >>> a=np.array([[1,2],[3,4]]) >>> a array([[1, 2], [3, 4]]) >>> np.fliplr(np.flipud(a)) array([[4, 3], [2, 1]]) |

Re: numpy array operationOn 1/29/2013 1:49 PM, Alok Singhal wrote:
> On Tue, 29 Jan 2013 00:41:54 -0800, C. Ng wrote: > >> Is there a numpy operation that does the following to the array? >> >> 1 2 ==> 4 3 >> 3 4 2 1 >> >> Thanks in advance. > > How about: > >>>> import numpy as np >>>> a = np.array([[1,2],[3,4]]) >>>> a > array([[1, 2], [3, 4]]) >>>> a[::-1, ::-1] > array([[4, 3], [2, 1]]) > Nice. The regular Python equivalent is a = [[1,2],[3,4]] print([row[::-1] for row in a[::-1]]) >>> [[4, 3], [2, 1]] The second slice can be replaced with reversed(a), which returns an iterator, to get [row[::-1] for row in reversed(a)] The first slice would have to be list(reversed(a)) to get the same result. -- Terry Jan Reedy |

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