Inner product between 2 matrices

[edwardnguyen1705]

Dear @romeric ,
Thanks for sharing your work.
Let see the following pieces of code:

Tensor<float,2,3> m1 = {{1,1},{2,2}};
Tensor<float,2,3> m2 = {{3,3},{4,4}};
Tensor<float,2,2> m3 = inner(m1, m2);

I would like it produces: m3 = {{1*3+1*3, 1*4+1*4}, {2*3+2*3, 2*4+2*4}}, but instead it produces: m3 = {{1*1+2*2+3*3 + 4*4+5*5+6*6, 1*1+2*2+3*3 + 4*4+5*5+6*6}, {1*1+2*2+3*3 + 4*4+5*5+6*6, 1*1+2*2+3*3 + 4*4+5*5+6*6}}
How would I change the code to get the desired the output?
Thanks for your time.

[romeric]

First of all, your tensor dimensions are incorrect, m1 and m2 should be 2x2 not 2x3.
Second, you are not describing an inner product between two matrices. You still want the output matrix to be 2x2 which is not a reduction operation (inner) operation. This is a very specific operation and the closest you can get it without doing it manually using Fastor is:

    Tensor<float,2,2> m1 = {{1,1},{2,2}};
    Tensor<float,2,2> m2 = {{3,3},{4,4}};

    Tensor<float,2,2> m3;
    m3(0,0) = inner(m1(fix<0>,all), m2(fix<0>,all));
    m3(0,1) = inner(m1(fix<0>,all), m2(fix<1>,all));
    m3(1,0) = inner(m1(fix<1>,all), m2(fix<0>,all));
    m3(1,1) = inner(m1(fix<1>,all), m2(fix<1>,all));