[Numpy-discussion] dot function or dot notation, matrices, arrays?

Wayne Watson sierra_mtnview@sbcglobal....
Fri Dec 18 16:51:25 CST 2009


That should do it. Thanks. How do I get the scalar result by itself?


Keith Goodman wrote:
> On Fri, Dec 18, 2009 at 1:51 PM, Wayne Watson
> <sierra_mtnview@sbcglobal.net> wrote:
>   
>> Is it possible to calculate a dot product in numpy by either notation
>> (a ^ b, where ^ is a possible notation) or calling a dot function
>> (dot(a,b)? I'm trying to use a column matrix for both "vectors".
>> Perhaps, I need to somehow change them to arrays?
>>     
>
> Does this do what you want?
>
>   
>>> x
>>>       
> matrix([[1],
>         [2],
>         [3]])
>
>   
>>> x.T * x
>>>       
>    matrix([[14]])
>   
>>> np.dot(x.T,x)
>>>       
>    matrix([[14]])
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>   

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           Wayne Watson (Watson Adventures, Prop., Nevada City, CA)

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