desc.magnetic_fields.FourierCurrentPotentialField.get_axis

FourierCurrentPotentialField.get_axis()Source

Get the axis of the surface.

This method calculates the axis of the surface by finding the mid point of the R and Z values at theta=0 and pi degrees for a bunch of toroidal angles and fitting a Fourier curve to it. For general non-convex surfaces, the geometric center (aka centroid) might not be inside the given surface. Since we use the axis for the initial guess of the magnetic axis, it is important to have the axis inside the surface, and form good nested flux surfaces. This method is a simple way to get a good initial guess for the axis.

Returns:

axis (FourierRZCurve) – Axis of the surface.