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Re: matrix math
by Miguel Negrao-2
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Dan Stowell escreveu:
> My personal opinion (just 2p worth) is that it's not appropriate for
> the core Array class since it's only applicable to a particular sort
> of array. The Matrix class add-on does include matrix multiplication
> etc, makes more sense there.
Is there a Matrix class ? I didn't find it... or are you suggesting one
should be made ? That would definetelly be usefull.
>
> By the way, instead of "if( this.flop.size == matrix.size)" use "if(
> this[0].size == matrix.size)". Why? Because .flop is pretty heavy duty
> for big matrices, so worth avoiding...
>
> Dan
always learning ;-)
Miguel
>
> 2008/5/12 Miguel Negrao <miguel.negrao@...>:
>> Thanks, that's simpler than the code i was working on. Maybe something
>> like this could be added to Array ?
>>
>> //this assumes array elements are rows of a matrix
>> + Array {
>>
>> mult { |matrix|
>>
>> if( this.flop.size == matrix.size)
>> { ^ this.collect{|row| (row * matrix).sum } }
>> { "Error: matrix dimensions mismatch".postln;
>> ^nil
>> }
>>
>> }
>> }
>>
>> Miguel
>>
>> Dan Stowell escreveu:
>>
>>
>>> Yes, I haven't used that class either but you may find it useful.
>> >
>> > In fact matrix multiplication can be written fairly compactly in plain SC:
>> >
>> > a = [[1, 0, 2], [-1, 3, 1]];
>> > b = [[3,1], [2,1], [1,0]];
>> >
>> > a.collect{|row| (row * b).sum }
>> >
>> > Dan
>> >
>> > 2008/5/12 Luke Selden <lselden@...>:
>> >> In the MathLib Quark there's a Matrix class that I haven't used but
>> >> might be worth looking into.
>> >>
>> >> ~luke
>> >>
>> >>
>> >>
>> >> On Mon, May 12, 2008 at 7:26 AM, Miguel Negrao
>> >> <miguel.negrao@...> wrote:
>> >> > Hi
>> >> >
>> >> > Is there a way to do linear algebra in sc, specifically matrix
>> >> > multiplication (matrix with matrix, matrix with vector,etc) ?
>> >> >
>> >> > thanks
>> >> > Miguel Negrão
>> >> > _______________________________________________
>> >> > sc-users mailing list
>> >> > sc-users@...
>> >> > http://lists.create.ucsb.edu/mailman/listinfo/sc-users
>> >> >
>> >> _______________________________________________
>> >> sc-users mailing list
>> >> sc-users@...
>> >> http://lists.create.ucsb.edu/mailman/listinfo/sc-users
>> >>
>> >
>> >
>> >
>>
>> _______________________________________________
>> sc-users mailing list
>> sc-users@...
>> http://lists.create.ucsb.edu/mailman/listinfo/sc-users
>>
>
>
>
_______________________________________________
sc-users mailing list
sc-users@...
http://lists.create.ucsb.edu/mailman/listinfo/sc-users
> My personal opinion (just 2p worth) is that it's not appropriate for
> the core Array class since it's only applicable to a particular sort
> of array. The Matrix class add-on does include matrix multiplication
> etc, makes more sense there.
Is there a Matrix class ? I didn't find it... or are you suggesting one
should be made ? That would definetelly be usefull.
>
> By the way, instead of "if( this.flop.size == matrix.size)" use "if(
> this[0].size == matrix.size)". Why? Because .flop is pretty heavy duty
> for big matrices, so worth avoiding...
>
> Dan
always learning ;-)
Miguel
>
> 2008/5/12 Miguel Negrao <miguel.negrao@...>:
>> Thanks, that's simpler than the code i was working on. Maybe something
>> like this could be added to Array ?
>>
>> //this assumes array elements are rows of a matrix
>> + Array {
>>
>> mult { |matrix|
>>
>> if( this.flop.size == matrix.size)
>> { ^ this.collect{|row| (row * matrix).sum } }
>> { "Error: matrix dimensions mismatch".postln;
>> ^nil
>> }
>>
>> }
>> }
>>
>> Miguel
>>
>> Dan Stowell escreveu:
>>
>>
>>> Yes, I haven't used that class either but you may find it useful.
>> >
>> > In fact matrix multiplication can be written fairly compactly in plain SC:
>> >
>> > a = [[1, 0, 2], [-1, 3, 1]];
>> > b = [[3,1], [2,1], [1,0]];
>> >
>> > a.collect{|row| (row * b).sum }
>> >
>> > Dan
>> >
>> > 2008/5/12 Luke Selden <lselden@...>:
>> >> In the MathLib Quark there's a Matrix class that I haven't used but
>> >> might be worth looking into.
>> >>
>> >> ~luke
>> >>
>> >>
>> >>
>> >> On Mon, May 12, 2008 at 7:26 AM, Miguel Negrao
>> >> <miguel.negrao@...> wrote:
>> >> > Hi
>> >> >
>> >> > Is there a way to do linear algebra in sc, specifically matrix
>> >> > multiplication (matrix with matrix, matrix with vector,etc) ?
>> >> >
>> >> > thanks
>> >> > Miguel Negrão
>> >> > _______________________________________________
>> >> > sc-users mailing list
>> >> > sc-users@...
>> >> > http://lists.create.ucsb.edu/mailman/listinfo/sc-users
>> >> >
>> >> _______________________________________________
>> >> sc-users mailing list
>> >> sc-users@...
>> >> http://lists.create.ucsb.edu/mailman/listinfo/sc-users
>> >>
>> >
>> >
>> >
>>
>> _______________________________________________
>> sc-users mailing list
>> sc-users@...
>> http://lists.create.ucsb.edu/mailman/listinfo/sc-users
>>
>
>
>
_______________________________________________
sc-users mailing list
sc-users@...
http://lists.create.ucsb.edu/mailman/listinfo/sc-users
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