Clamping the step-size

[ivan-pi]

stiff3/src/stiff3_solver.f90

Lines 209 to 210 in 057a699

	qa = 1.0_wp/(qa+1.0e-10_wp)
	if (qa > 3.0_wp) qa = 3.0_wp

The step size is controlled by the factor qa (the ratio $h_{i+1}/h_i$), and could be written more succintly as:

qa = 1.0_wp/((4*q)**0.25_wp + eps)
qa = min(qa,3.0_wp)