How to do the following matrix multiplication and division?

I have Frequency as a 22x1 column vector, and the following equation must produce 22x1 column vector [all other variables are scalars]

Lorentz_Imaginary_conductivity = DC_Conductivity * ((time * Frequency .* (1 - Oscillator_frequency^2 / Frequency.^2)) ... 
    ./ (1 + (time .* Frequency .* (1 - Oscillator_frequency^2 ./ Frequency.^2)).^2));

But instead it gives 22x22 matrix. What is the problem here?

Answer 1

[jessupj]

(1 - Oscillator_frequency^2 / Frequency.^2))

this slash needs to be a './' or it's interpreted as a matrix inverison... htat's where your 22x22 is coming from

[John D'Errico]

Not technically a matrix inverse or a matrix inversion there, but it will be interpreted as an operation using linear algebra where a linear system of equaions will be solved, instead of an element-wise divide. So, yes. Use ./ for the proper result.

[Ahmed Razeen]

Yea, That worked. Thank you very much

[jessupj]

my bad for being sloppy. this is not technically a matrix inversion of course. most control/inverse problem folks that i know conisider 'scalar divided by a vector' an inverison (e.g. of a moment), at least conceputally.