Re: [eigen] Array cwise multiplication

[Benoit Jacob <jacob.benoit.1@xxxxxxxxx>]

the asDiagonal() way is completely optimized.

It doesn't hurt to file a bug, I agree that colwise multiplication should work.

Benoit

2010/9/29 Carlos Becker <carlosbecker@xxxxxxxxx>:
> That's a good idea, should I report this as a bug?
> on the other hand, .asDiagonal() will return a diagonal object and it is
> evaluated as a diagonal matrix, with its respective optimization?
> Thanks
>
>
> On Wed, Sep 29, 2010 at 8:37 PM, Benoit Jacob <jacob.benoit.1@xxxxxxxxx>
> wrote:
>>
>> meanwhile you can do the same with a diagonal product:
>>
>> a * b.asDiagonal()
>>
>> or
>>
>> b.asDiagonal() * a
>>
>> 2010/9/29 Carlos Becker <carlosbecker@xxxxxxxxx>:
>> > The strange things is that operator + and - work, but I guess that might
>> > come from Matrix. So there is something strange going on with array
>> > colwise() and rowwise() (just tested that too, very quick, and seems to
>> > have
>> > the same problems).
>> >
>> >
>> > On Wed, Sep 29, 2010 at 8:09 PM, Benoit Jacob <jacob.benoit.1@xxxxxxxxx>
>> > wrote:
>> >>
>> >> erm, ignore me, that didn't make sense.
>> >>
>> >> 2010/9/29 Benoit Jacob <jacob.benoit.1@xxxxxxxxx>:
>> >> > ah, i know.
>> >> >
>> >> > b is a column-vector. you can't multiply colwise by it.
>> >> >
>> >> > Either make it a row-vector or multiply rowwise by it.
>> >> >
>> >> > 2010/9/29 Carlos Becker <carlosbecker@xxxxxxxxx>:
>> >> >> I already tried that, and still doesn't work. I get the following
>> >> >> error
>> >> >> (sorry for the flooding)
>> >> >> test.cpp:20: error: no match for ‘operator*’ in
>> >> >> ‘((Eigen::DenseBase<Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, -0x00000000000000001, 0, -0x00000000000000001,
>> >> >> -0x00000000000000001> >
>> >> >> >*)(&((Eigen::MatrixBase<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, -0x00000000000000001, 0, -0x00000000000000001,
>> >> >> -0x00000000000000001> >*)(& a))->Eigen::MatrixBase<Derived>::array
>> >> >> [with
>> >> >> Derived = Eigen::Matrix<float, -0x00000000000000001,
>> >> >> -0x00000000000000001,
>> >> >> 0, -0x00000000000000001,
>> >> >> -0x00000000000000001>]()))->Eigen::DenseBase<Derived>::colwise [with
>> >> >> Derived
>> >> >> = Eigen::ArrayWrapper<Eigen::Matrix<float, -0x00000000000000001,
>> >> >> -0x00000000000000001, 0, -0x00000000000000001, -0x00000000000000001>
>> >> >> >]() *
>> >> >> ((Eigen::MatrixBase<Eigen::Matrix<float, -0x00000000000000001, 1, 0,
>> >> >> -0x00000000000000001, 1> >*)(&
>> >> >> b))->Eigen::MatrixBase<Derived>::array
>> >> >> [with
>> >> >> Derived = Eigen::Matrix<float, -0x00000000000000001, 1, 0,
>> >> >> -0x00000000000000001, 1>]()’
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:95: note:
>> >> >> candidates
>> >> >> are:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple2_op<float,
>> >> >> std::complex<float> >, Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, 1, 0, -0x00000000000000001, 1> > >
>> >> >> Eigen::operator*(const std::complex<float>&, const
>> >> >> Eigen::ArrayBase<Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, 1, 0, -0x00000000000000001, 1> > >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:91: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple_op<float>,
>> >> >> Eigen::ArrayWrapper<Eigen::Matrix<float, -0x00000000000000001, 1, 0,
>> >> >> -0x00000000000000001, 1> > > Eigen::operator*(const float&, const
>> >> >> Eigen::ArrayBase<Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, 1, 0, -0x00000000000000001, 1> > >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:95: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple2_op<float,
>> >> >> std::complex<float> >, Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, -0x00000000000000001, 0, -0x00000000000000001,
>> >> >> -0x00000000000000001> > > Eigen::operator*(const
>> >> >> std::complex<float>&,
>> >> >> const
>> >> >> Eigen::ArrayBase<Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, -0x00000000000000001, 0, -0x00000000000000001,
>> >> >> -0x00000000000000001> > >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:91: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple_op<float>,
>> >> >> Eigen::ArrayWrapper<Eigen::Matrix<float, -0x00000000000000001,
>> >> >> -0x00000000000000001, 0, -0x00000000000000001, -0x00000000000000001>
>> >> >> >
>> >> >> >
>> >> >> Eigen::operator*(const float&, const
>> >> >> Eigen::ArrayBase<Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, -0x00000000000000001, 0, -0x00000000000000001,
>> >> >> -0x00000000000000001> > >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:95: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple2_op<float,
>> >> >> std::complex<float> >, Eigen::Matrix<float, -0x00000000000000001,
>> >> >> -0x00000000000000001, 0, -0x00000000000000001, -0x00000000000000001>
>> >> >> >
>> >> >> Eigen::operator*(const std::complex<float>&, const
>> >> >> Eigen::MatrixBase<Eigen::Matrix<float, -0x00000000000000001,
>> >> >> -0x00000000000000001, 0, -0x00000000000000001, -0x00000000000000001>
>> >> >> >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:91: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple_op<float>,
>> >> >> Eigen::Matrix<float, -0x00000000000000001, -0x00000000000000001, 0,
>> >> >> -0x00000000000000001, -0x00000000000000001> > Eigen::operator*(const
>> >> >> float&,
>> >> >> const Eigen::MatrixBase<Eigen::Matrix<float, -0x00000000000000001,
>> >> >> -0x00000000000000001, 0, -0x00000000000000001, -0x00000000000000001>
>> >> >> >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:95: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple2_op<float,
>> >> >> std::complex<float> >, Eigen::Matrix<float, -0x00000000000000001, 1,
>> >> >> 0,
>> >> >> -0x00000000000000001, 1> > Eigen::operator*(const
>> >> >> std::complex<float>&,
>> >> >> const Eigen::MatrixBase<Eigen::Matrix<float, -0x00000000000000001,
>> >> >> 1,
>> >> >> 0,
>> >> >> -0x00000000000000001, 1> >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:91: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple_op<float>,
>> >> >> Eigen::Matrix<float, -0x00000000000000001, 1, 0,
>> >> >> -0x00000000000000001,
>> >> >> 1> >
>> >> >> Eigen::operator*(const float&, const
>> >> >> Eigen::MatrixBase<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, 1, 0, -0x00000000000000001, 1> >&)
>> >> >> [2]+  Done                    gedit test.cpp
>> >> >> cjb@cjb-laptop:/tmp/eigen$ g++ test.cpp -I.
>> >> >> test.cpp: In function ‘int main()’:
>> >> >> test.cpp:20: error: no match for ‘operator*’ in
>> >> >> ‘((Eigen::DenseBase<Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, -0x00000000000000001, 0, -0x00000000000000001,
>> >> >> -0x00000000000000001> >
>> >> >> >*)(&((Eigen::MatrixBase<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, -0x00000000000000001, 0, -0x00000000000000001,
>> >> >> -0x00000000000000001> >*)(& a))->Eigen::MatrixBase<Derived>::array
>> >> >> [with
>> >> >> Derived = Eigen::Matrix<float, -0x00000000000000001,
>> >> >> -0x00000000000000001,
>> >> >> 0, -0x00000000000000001,
>> >> >> -0x00000000000000001>]()))->Eigen::DenseBase<Derived>::colwise [with
>> >> >> Derived
>> >> >> = Eigen::ArrayWrapper<Eigen::Matrix<float, -0x00000000000000001,
>> >> >> -0x00000000000000001, 0, -0x00000000000000001, -0x00000000000000001>
>> >> >> >]() *
>> >> >> ((Eigen::MatrixBase<Eigen::Matrix<float, -0x00000000000000001, 1, 0,
>> >> >> -0x00000000000000001, 1> >*)(&
>> >> >> b))->Eigen::MatrixBase<Derived>::array
>> >> >> [with
>> >> >> Derived = Eigen::Matrix<float, -0x00000000000000001, 1, 0,
>> >> >> -0x00000000000000001, 1>]()’
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:95: note:
>> >> >> candidates
>> >> >> are:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple2_op<float,
>> >> >> std::complex<float> >, Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, 1, 0, -0x00000000000000001, 1> > >
>> >> >> Eigen::operator*(const std::complex<float>&, const
>> >> >> Eigen::ArrayBase<Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, 1, 0, -0x00000000000000001, 1> > >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:91: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple_op<float>,
>> >> >> Eigen::ArrayWrapper<Eigen::Matrix<float, -0x00000000000000001, 1, 0,
>> >> >> -0x00000000000000001, 1> > > Eigen::operator*(const float&, const
>> >> >> Eigen::ArrayBase<Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, 1, 0, -0x00000000000000001, 1> > >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:95: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple2_op<float,
>> >> >> std::complex<float> >, Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, -0x00000000000000001, 0, -0x00000000000000001,
>> >> >> -0x00000000000000001> > > Eigen::operator*(const
>> >> >> std::complex<float>&,
>> >> >> const
>> >> >> Eigen::ArrayBase<Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, -0x00000000000000001, 0, -0x00000000000000001,
>> >> >> -0x00000000000000001> > >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:91: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple_op<float>,
>> >> >> Eigen::ArrayWrapper<Eigen::Matrix<float, -0x00000000000000001,
>> >> >> -0x00000000000000001, 0, -0x00000000000000001, -0x00000000000000001>
>> >> >> >
>> >> >> >
>> >> >> Eigen::operator*(const float&, const
>> >> >> Eigen::ArrayBase<Eigen::ArrayWrapper<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, -0x00000000000000001, 0, -0x00000000000000001,
>> >> >> -0x00000000000000001> > >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:95: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple2_op<float,
>> >> >> std::complex<float> >, Eigen::Matrix<float, -0x00000000000000001,
>> >> >> -0x00000000000000001, 0, -0x00000000000000001, -0x00000000000000001>
>> >> >> >
>> >> >> Eigen::operator*(const std::complex<float>&, const
>> >> >> Eigen::MatrixBase<Eigen::Matrix<float, -0x00000000000000001,
>> >> >> -0x00000000000000001, 0, -0x00000000000000001, -0x00000000000000001>
>> >> >> >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:91: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple_op<float>,
>> >> >> Eigen::Matrix<float, -0x00000000000000001, -0x00000000000000001, 0,
>> >> >> -0x00000000000000001, -0x00000000000000001> > Eigen::operator*(const
>> >> >> float&,
>> >> >> const Eigen::MatrixBase<Eigen::Matrix<float, -0x00000000000000001,
>> >> >> -0x00000000000000001, 0, -0x00000000000000001, -0x00000000000000001>
>> >> >> >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:95: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple2_op<float,
>> >> >> std::complex<float> >, Eigen::Matrix<float, -0x00000000000000001, 1,
>> >> >> 0,
>> >> >> -0x00000000000000001, 1> > Eigen::operator*(const
>> >> >> std::complex<float>&,
>> >> >> const Eigen::MatrixBase<Eigen::Matrix<float, -0x00000000000000001,
>> >> >> 1,
>> >> >> 0,
>> >> >> -0x00000000000000001, 1> >&)
>> >> >> ./Eigen/src/Core/../plugins/CommonCwiseUnaryOps.h:91: note:
>> >> >> const Eigen::CwiseUnaryOp<Eigen::ei_scalar_multiple_op<float>,
>> >> >> Eigen::Matrix<float, -0x00000000000000001, 1, 0,
>> >> >> -0x00000000000000001,
>> >> >> 1> >
>> >> >> Eigen::operator*(const float&, const
>> >> >> Eigen::MatrixBase<Eigen::Matrix<float,
>> >> >> -0x00000000000000001, 1, 0, -0x00000000000000001, 1> >&)
>> >> >>
>> >> >>
>> >> >> On Wed, Sep 29, 2010 at 7:49 PM, Benoit Jacob
>> >> >> <jacob.benoit.1@xxxxxxxxx>
>> >> >> wrote:
>> >> >>>
>> >> >>> Does a.array().colwise() * b.array() work ?
>> >> >>>
>> >> >>> We're a bit pedantic if we require putting array() here since the
>> >> >>> colwise() makes it clear what you want to do...
>> >> >>>
>> >> >>> Benoit
>> >> >>>
>> >> >>> 2010/9/29 Carlos Becker <carlosbecker@xxxxxxxxx>:
>> >> >>> > Hi Benoit. No, it doesn't work and it makes sense, since it would
>> >> >>> > be
>> >> >>> > like
>> >> >>> > multiplying a vector by a vector algebraically, which has no
>> >> >>> > sense
>> >> >>> > for a
>> >> >>> > Matrix type (has it?)
>> >> >>> > I wanted to do element-wise multiplication, and I thought that
>> >> >>> > .array().colwise() would cope with that. Just to clarify, I want
>> >> >>> > to
>> >> >>> > do:
>> >> >>> > if A = [1 2;
>> >> >>> >           3 4]
>> >> >>> > and B = [a;b] (matlab notation)
>> >> >>> > then I want to get something like:
>> >> >>> > result = [ 1*a, 2*a;
>> >> >>> >              3*b 4*b ]
>> >> >>> > Should I do this another way? I thought that .array().colwise()
>> >> >>> > was
>> >> >>> > defined
>> >> >>> > to apply the element-wise operation for every column vector in A.
>> >> >>> > Thanks
>> >> >>> >
>> >> >>> > On Wed, Sep 29, 2010 at 7:41 PM, Benoit Jacob
>> >> >>> > <jacob.benoit.1@xxxxxxxxx>
>> >> >>> > wrote:
>> >> >>> >>
>> >> >>> >> 2010/9/29 Carlos Becker <carlosbecker@xxxxxxxxx>:
>> >> >>> >> > Hi all, I was trying to code something like this:
>> >> >>> >> > #include <Eigen/Dense>
>> >> >>> >> > using namespace Eigen;
>> >> >>> >> > using namespace std;
>> >> >>> >> > int main()
>> >> >>> >> > {
>> >> >>> >> > MatrixXf a;
>> >> >>> >> > VectorXf b;
>> >> >>> >> > a.resize(2,4);
>> >> >>> >> > b.resize(2);
>> >> >>> >> > a << 1,2,
>> >> >>> >> > 3,4,
>> >> >>> >> > 5,6,
>> >> >>> >> > 7,8;
>> >> >>> >> > b << 1,2;
>> >> >>> >> > a = a.array().colwise() * b;
>> >> >>> >>
>> >> >>> >> Here you're multiplying an array by a matrix.
>> >> >>> >>
>> >> >>> >> Doesn't a.colwise() * b work?
>> >> >>> >>
>> >> >>> >> Benoit
>> >> >>> >>
>> >> >>> >> > return 0;
>> >> >>> >> > }
>> >> >>> >> > Should this compile correctly? I want to multiply every column
>> >> >>> >> > in
>> >> >>> >> > matrix
>> >> >>> >> > a,
>> >> >>> >> > element-wise, with vector b, but I cannot make it work
>> >> >>> >> > I hope I am not forgetting about something important here.
>> >> >>> >> > Cheers,
>> >> >>> >> > Carlos
>> >> >>> >>
>> >> >>> >>
>> >> >>> >
>> >> >>> >
>> >> >>>
>> >> >>>
>> >> >>
>> >> >>
>> >> >
>> >>
>> >>
>> >
>> >
>>
>>
>
>