diff options
Diffstat (limited to 'fg21sim/extragalactic/clusters/solver.py')
| -rw-r--r-- | fg21sim/extragalactic/clusters/solver.py | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/fg21sim/extragalactic/clusters/solver.py b/fg21sim/extragalactic/clusters/solver.py index da6b4d4..f7724dd 100644 --- a/fg21sim/extragalactic/clusters/solver.py +++ b/fg21sim/extragalactic/clusters/solver.py @@ -104,6 +104,7 @@ class FokkerPlanckSolver: boundary. The densities within this buffer region will be replaced by extrapolating an power law to avoid unphysical accumulations. This fix is ignored if this parameter is not specified. + (This parameter is suggested to be about 5%-10% of ``x_np``.) NOTE ---- @@ -332,7 +333,11 @@ class FokkerPlanckSolver: is determined by fitting to the data points of ``self.buffer_np`` cells on the upper side of the buffer region. - TODO: also fix the upper boundary in the same way? + NOTE + ---- + * Also fix the upper boundary in the same way. + * Fix the boundaries only when the particles are piling up at the + boundaries. References: Ref.[donnert2014],Sec.(3.3) """ @@ -343,15 +348,30 @@ class FokkerPlanckSolver: return uc x = self.x - # Calculate the power-law index for ``self.buffer_np`` from data - # points just right of the buffer region. - xp = x[self.buffer_np:(self.buffer_np*2)] - yp = uc[self.buffer_np:(self.buffer_np*2)] - # Power-law fit - pfit = np.polyfit(np.log10(xp), np.log10(yp), deg=1) - xbuf = x[:self.buffer_np] - ybuf = 10 ** np.polyval(pfit, np.log10(xbuf)) - uc[:self.buffer_np] = ybuf + # Lower boundary + ybuf = uc[:self.buffer_np] + if ybuf[0] > ybuf[1]: + # Particles are piling up at the lower boundary, to fix it... + # + # Power-law fit + xp = x[self.buffer_np:(self.buffer_np*2)] + yp = uc[self.buffer_np:(self.buffer_np*2)] + pfit = np.polyfit(np.log(xp), np.log(yp), deg=1) + xbuf = x[:self.buffer_np] + ybuf = np.exp(np.polyval(pfit, np.log(xbuf))) + uc[:self.buffer_np] = ybuf + + # Upper boundary + ybuf = uc[(-self.buffer_np):] + if ybuf[-1] > ybuf[-2]: + # Particles are piling up at the upper boundary, to fix it... + xp = x[(-self.buffer_np*2):(-self.buffer_np)] + yp = uc[(-self.buffer_np*2):(-self.buffer_np)] + pfit = np.polyfit(np.log(xp), np.log(yp), deg=1) + xbuf = x[(-self.buffer_np):] + ybuf = np.exp(np.polyval(pfit, np.log(xbuf))) + uc[(-self.buffer_np):] = ybuf + return uc def time_step(self): |