root / ase / optimize / fire.py @ 3
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| 1 | 1 | tkerber | import numpy as np |
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| 2 | 1 | tkerber | |
| 3 | 1 | tkerber | from ase.optimize.optimize import Optimizer |
| 4 | 1 | tkerber | |
| 5 | 1 | tkerber | |
| 6 | 1 | tkerber | class FIRE(Optimizer): |
| 7 | 1 | tkerber | def __init__(self, atoms, restart=None, logfile='-', trajectory=None, |
| 8 | 1 | tkerber | dt=0.1, maxmove=0.2, dtmax=1.0, Nmin=5, finc=1.1, fdec=0.5, |
| 9 | 1 | tkerber | astart=0.1, fa=0.99, a=0.1): |
| 10 | 1 | tkerber | Optimizer.__init__(self, atoms, restart, logfile, trajectory)
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| 11 | 1 | tkerber | |
| 12 | 1 | tkerber | self.dt = dt
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| 13 | 1 | tkerber | self.Nsteps = 0 |
| 14 | 1 | tkerber | self.maxmove = maxmove
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| 15 | 1 | tkerber | self.dtmax = dtmax
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| 16 | 1 | tkerber | self.Nmin = Nmin
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| 17 | 1 | tkerber | self.finc = finc
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| 18 | 1 | tkerber | self.fdec = fdec
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| 19 | 1 | tkerber | self.astart = astart
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| 20 | 1 | tkerber | self.fa = fa
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| 21 | 1 | tkerber | self.a = a
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| 22 | 1 | tkerber | |
| 23 | 1 | tkerber | def initialize(self): |
| 24 | 1 | tkerber | self.v = None |
| 25 | 1 | tkerber | |
| 26 | 1 | tkerber | def read(self): |
| 27 | 1 | tkerber | self.v, self.dt = self.load() |
| 28 | 1 | tkerber | |
| 29 | 1 | tkerber | def step(self,f): |
| 30 | 1 | tkerber | atoms = self.atoms
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| 31 | 1 | tkerber | if self.v is None: |
| 32 | 1 | tkerber | self.v = np.zeros((len(atoms), 3)) |
| 33 | 1 | tkerber | else:
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| 34 | 1 | tkerber | vf = np.vdot(f, self.v)
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| 35 | 1 | tkerber | if vf > 0.0: |
| 36 | 1 | tkerber | self.v = (1.0 - self.a) * self.v + self.a * f / np.sqrt( |
| 37 | 1 | tkerber | np.vdot(f, f)) * np.sqrt(np.vdot(self.v, self.v)) |
| 38 | 1 | tkerber | if self.Nsteps > self.Nmin: |
| 39 | 1 | tkerber | self.dt = min(self.dt * self.finc, self.dtmax) |
| 40 | 1 | tkerber | self.a *= self.fa |
| 41 | 1 | tkerber | self.Nsteps += 1 |
| 42 | 1 | tkerber | else:
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| 43 | 1 | tkerber | self.v[:] *= 0.0 |
| 44 | 1 | tkerber | self.a = self.astart |
| 45 | 1 | tkerber | self.dt *= self.fdec |
| 46 | 1 | tkerber | self.Nsteps = 0 |
| 47 | 1 | tkerber | # if vf < 0.0:
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| 48 | 1 | tkerber | # self.v[:] = 0.0
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| 49 | 1 | tkerber | # self.a = self.astart
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| 50 | 1 | tkerber | # self.dt *= self.fdec
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| 51 | 1 | tkerber | # self.Nsteps = 0
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| 52 | 1 | tkerber | # else:
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| 53 | 1 | tkerber | # self.v = (1.0 - self.a) * self.v + self.a * f * np.sqrt(
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| 54 | 1 | tkerber | # np.vdot(f, f) / np.vdot(self.v, self.v))
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| 55 | 1 | tkerber | # if self.Nsteps > self.Nmin:
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| 56 | 1 | tkerber | # dt = min(dt * self.finc, dtmax)
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| 57 | 1 | tkerber | # self.a *= self.fa
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| 58 | 1 | tkerber | # self.Nsteps += 1
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| 59 | 1 | tkerber | |
| 60 | 1 | tkerber | self.v += self.dt * f |
| 61 | 1 | tkerber | dr = self.dt * self.v |
| 62 | 1 | tkerber | normdr = np.sqrt(np.vdot(dr, dr)) |
| 63 | 1 | tkerber | if normdr > self.maxmove: |
| 64 | 1 | tkerber | dr = self.maxmove * dr / normdr
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| 65 | 1 | tkerber | r = atoms.get_positions() |
| 66 | 1 | tkerber | atoms.set_positions(r + dr) |
| 67 | 1 | tkerber | self.dump((self.v, self.dt)) |