In the calculation of the Toomre Q parameter, the rotating frame was not considered.
This pull request introduces a fix.
The simplest way of adding the rotating frame is to add r*OmegaFrame to the azimuthal velocities before computing the numerical derivative.
My attempts at expanding the analytical expression were all much more complicated expressions which need more operations to compute.
In the calculation of the Toomre Q parameter, the rotating frame was not considered. This pull request introduces a fix.
The simplest way of adding the rotating frame is to add r*OmegaFrame to the azimuthal velocities before computing the numerical derivative. My attempts at expanding the analytical expression were all much more complicated expressions which need more operations to compute.