* Added return of None values for function calc_rotating_frame_params() if spin is not selected. Regarding [https://gna.org/support/?3124 sr #3124, Grace graphs production for R<sub>1ρ</sub> analysis with R<sub>2eff</sub> as function of Ω<sub>eff</sub>].
* Extended system test Relax_disp.test_value_write_calc_rotating_frame_params_auto_analysis() to test the writing of θ values. Regarding [https://gna.org/support/?3124 sr #3124, Grace graphs production for R<sub>1ρ</sub> analysis with R<sub>2eff</sub> as function of Ω<sub>eff</sub>].
* Hardcoded the writing of R<sub>2eff</sub> as function of the tilt angle θ, when using the [http://www.nmr-relax.com/manual/relax_disp_write_disp_curves.html user function relax_disp.write_disp_curves] . Regarding [https://gna.org/support/?3124 sr #3124, Grace graphs production for R<sub>1ρ</sub> analysis with R<sub>2eff</sub> as function of Ω<sub>eff</sub>]. θ values per spin will be written if the spin.model is in the list MODEL_LIST_R1RHO_FULL.
* Fix for return of None tuble in calc_rotating_frame_params(). Regarding [https://gna.org/support/?3124 sr #3124, Grace graphs production for R<sub>1ρ</sub> analysis with R<sub>2eff</sub> as function of Ω<sub>eff</sub>].
* Fix for correct use of assertNotEqual or assertEqual in Relax_disp system tests. Regarding [https://gna.org/support/?3124 sr #3124, Grace graphs production for R<sub>1ρ</sub> analysis with R<sub>2eff</sub> as function of Ω<sub>eff</sub>].