How to multiply row-wise by scalar in pytorch?












2















When I have a tensor m of shape [12, 10] and a vector s of scalars with shape [12], how can I multiply each row of m with the corresponding scalar in s?






pytorch tensor scalar







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    2















    When I have a tensor m of shape [12, 10] and a vector s of scalars with shape [12], how can I multiply each row of m with the corresponding scalar in s?






    pytorch tensor scalar







    share|improve this question



























      2












      2








      2








      When I have a tensor m of shape [12, 10] and a vector s of scalars with shape [12], how can I multiply each row of m with the corresponding scalar in s?






      pytorch tensor scalar







      share|improve this question
















      When I have a tensor m of shape [12, 10] and a vector s of scalars with shape [12], how can I multiply each row of m with the corresponding scalar in s?






      pytorch tensor scalar




      pytorch tensor scalar






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Jan 1 at 6:18









      Shai

      70.2k23137246




      70.2k23137246










      asked Dec 31 '18 at 13:11









      ChrisChris

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      400526
























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          You need to add a corresponding singleton dimension:



          m * s[:, None]


          s[:, None] has size of (12, 1) when multiplying a (12, 10) tensor by a (12, 1) tensor pytoch knows to broadcast s along the second singleton dimension and perform the "element-wise" product correctly.






          share|improve this answer























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            1 Answer
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            active

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            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            3














            You need to add a corresponding singleton dimension:



            m * s[:, None]


            s[:, None] has size of (12, 1) when multiplying a (12, 10) tensor by a (12, 1) tensor pytoch knows to broadcast s along the second singleton dimension and perform the "element-wise" product correctly.






            share|improve this answer




























              3














              You need to add a corresponding singleton dimension:



              m * s[:, None]


              s[:, None] has size of (12, 1) when multiplying a (12, 10) tensor by a (12, 1) tensor pytoch knows to broadcast s along the second singleton dimension and perform the "element-wise" product correctly.






              share|improve this answer


























                3












                3








                3







                You need to add a corresponding singleton dimension:



                m * s[:, None]


                s[:, None] has size of (12, 1) when multiplying a (12, 10) tensor by a (12, 1) tensor pytoch knows to broadcast s along the second singleton dimension and perform the "element-wise" product correctly.






                share|improve this answer













                You need to add a corresponding singleton dimension:



                m * s[:, None]


                s[:, None] has size of (12, 1) when multiplying a (12, 10) tensor by a (12, 1) tensor pytoch knows to broadcast s along the second singleton dimension and perform the "element-wise" product correctly.







                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Dec 31 '18 at 14:29









                ShaiShai

                70.2k23137246




                70.2k23137246
































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