from PR #677 commits from @lheagy review from @sgkang, @rowanc1 tl; dr inductive source bug fix for permeable targets solve the magnetostatic problem for inductive sources that have initial fields new waveforms: trapezoid, quarter-sine ramp on Bug Fix: TDEM Inductive sources + permeable targets How we initially calculated the source term for inductive sources when the model includes permeability was incorrect (I found this by comparing a magnetostatic solution with a late on-time solution. The late on-time solution matched the case where no permeable material was included), this pr fixes that for the E-B formulation. In addition, we now have the option to solve the magnetostatic problem for initial fields when permeable material is included, so a shut-off waveform can be used when permeable materials are in the domain There is now a test to ensure that inductive sources are treating permeability properly New Waveforms TrapezoidWaveform and QuarterSineRampOnWaveform offTime=10 quarter_sine = TDEM.Src.QuarterSineRampOnWaveform(ramp_on=np.r_[0., 3], ramp_off=offTime - np.r_[1., 0] ) trapezoid = TDEM.Src.TrapezoidWaveform(ramp_on=np.r_[0., 3], ramp_off=offTime - np.r_[1., 0] ) nT = 1000 time = 10.*np.arange(nT)/nT quarter_sine_plt = np.r_[[quarter_sine.eval(t) for t in time]] trapezoid_plt = np.r_[[trapezoid.eval(t) for t in time]] fig, ax = plt.subplots(1, 2, figsize=(8, 4)) ax[0].plot(time, quarter_sine_plt) ax[0].set_title('quarter sine waveform') ax[1].plot(time, trapezoid_plt) ax[1].set_title('trapezoid waveform') plt.tight_layout()