Reference point when generating mooring stiffness

[jiayaomeng]

Dear developers,

I am hoping to double-check on a couple of details:

• Is the unit of rotation angle 'deg' or 'rad'? e.g., Do I set moor.displace_vessel(0,0,0,0,10,0) or moor.displace_vessel(0,0,0,0,10/180*np.pi,0), if I want to tilt the platform by 10 deg around Y axis?
• Does the reference point use absolute or relative coordinates? e.g. If I want to determine the mooring stiffness around the body-fixed frame origin after the platform is displaced 20m along X axis, i.e. moor.displace_vessel(20,0,0,0,0,0), do I set K, f0 = moor.stiffness_matrix(epsilon=1e-5, point=(0,0,0)) or K, f0 = moor.stiffness_matrix(epsilon=1e-5, point=(20,0,0))?

Thank you in advance for your help!

Best wishes,
Jiayao

[gbarter]

Hi Jiayao,

Unfortunately, the pyMAP is old enough that the development team has moved on and I don't know the quick answer to your question. My best suggestion is to track things through the source code to try to find the answer.

Most of our mooring studies have moved to MoorPy or MoorDyn instead of pyMAP.

Apologies I couldn't be more helpful.

[jiayaomeng]

Many thanks, @gbarter, for your suggestion!