[Numpy-discussion] Generalize hstack/vstack --> stack; Block matrices like in matlab

[cjw]

On 08-Sep-14 4:40 PM, Joseph Martinot-Lagarde wrote:
> Le 08/09/2014 15:29, Stefan Otte a écrit :
>> Hey,
>>
>> quite often I work with block matrices. Matlab offers the convenient notation
>>
>>       [ a b; c d ]
This would appear to be a desirable way to go.

Numpy has something similar for strings.  The above is neater.

Colin W.
>> to stack matrices. The numpy equivalent is kinda clumsy:
>>
>> vstack([hstack([a,b]), hstack([c,d])])
>>
>> I wrote the little function `stack` that does exactly that:
>>
>>       stack([[a, b], [c, d]])
>>
>> In my case `stack` replaced `hstack` and `vstack` almost completely.
>>
>> If you're interested in including it in numpy I created a pull request
>> [1]. I'm looking forward to getting some feedback!
>>
>>
>> Best,
>>    Stefan
>>
>>
>>
>> [1] https://github.com/numpy/numpy/pull/5057
>>
> The outside brackets are redundant, stack([[a, b], [c, d]]) should be
> stack([a, b], [c, d])
>
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