Example #1
0
    def minimize(self):
        nreps = self.nrep
        nbins = self.nebins
        visitsT = (self.visits1d)
        #print "min vis", np.min(visitsT)
        self.logP = np.where(visitsT != 0, np.log(visitsT), 0)
        #print "minlogp", np.min(self.logP)
        self.reduced_energy = self.binenergy[np.newaxis, :] / (
            self.Tlist[:, np.newaxis] * self.k_B)

        self.whampot = WhamPotential(self.logP, self.reduced_energy)

        X = np.random.rand(nreps + nbins)
        E = self.whampot.getEnergy(X)
        #print "energy", E

        #print "quenching"
        try:
            from pygmin.optimize import mylbfgs as quench
            ret = quench(X, self.whampot, iprint=-1, maxstep=1e4)
        except ImportError:
            from pygmin.optimize import lbfgs_scipy as quench
            ret = quench(X, self.whampot)
        #print "quench energy", ret.energy
        X = ret.coords

        self.logn_E = X[nreps:]
        self.w_i_final = X[:nreps]
    def minimize(self):
        #shape(visits2d) is now (nqbins, nebins, nreps)
        #we need it to be (nreps, nqbins*nebins)
        #first reorder indices
        nreps = self.nrep
        nebins = self.nebins
        nqbins = self.nqbins
        nbins = self.nebins * self.nqbins

        reduced_energy = np.zeros([nreps, nebins, nqbins])
        for j in range(self.nqbins):
            reduced_energy[:, :, j] = self.binenergy[np.newaxis, :] / (
                self.Tlist[:, np.newaxis] * self.k_B)

        visits = self.visits2d
        visits = np.reshape(visits, [nreps, nbins])
        reduced_energy = np.reshape(reduced_energy, [nreps, nbins])
        self.logP = np.where(visits != 0, np.log(visits.astype(float)), 0)

        from wham_potential import WhamPotential
        whampot = WhamPotential(visits, reduced_energy)

        nvar = nbins + nreps
        if False:
            X = np.random.rand(nvar)
        else:
            # estimate an initial guess for the offsets and density of states
            # so the minimizer converges more rapidly
            offsets_estimate, log_dos_estimate = wham_utils.estimate_dos(
                visits, reduced_energy)
            X = np.concatenate((offsets_estimate, log_dos_estimate))
            assert X.size == nvar

        E0, grad = whampot.getEnergyGradient(X)
        rms0 = np.linalg.norm(grad) / np.sqrt(grad.size)

        from wham_utils import lbfgs_scipy
        ret = lbfgs_scipy(X, whampot)
        #        print "initial energy", whampot.getEnergy(X)
        #        try:
        #            from pele.optimize import mylbfgs as quench
        #            ret = quench(X, whampot, iprint=10, maxstep = 1e4)
        #        except ImportError:
        #            from pele.optimize import lbfgs_scipy as quench
        #            ret = quench(X, whampot)

        if self.verbose:
            print "chi^2 went from %g (rms %g) to %g (rms %g) in %d iterations" % (
                E0, rms0, ret.energy, ret.rms, ret.nfev)

        #self.logn_Eq = zeros([nebins,nqbins], float64)
        X = ret.coords
        self.logn_Eq = X[nreps:]
        self.w_i_final = X[:nreps]

        self.logn_Eq = np.reshape(self.logn_Eq, [nebins, nqbins])
        self.logn_Eq = np.where(
            self.visits2d.sum(0) == 0, self.LOGMIN, self.logn_Eq)
Example #3
0
    def minimize(self):
        #shape(visits2d) is now (nqbins, nebins, nreps)
        #we need it to be (nreps, nqbins*nebins)
        #first reorder indices
        nreps = self.nrep
        nebins = self.nebins
        nqbins = self.nqbins
        nbins = self.nebins * self.nqbins
        #visits = np.zeros([nreps, nebins, nqbins], np.integer)
        reduced_energy = np.zeros([nreps, nebins, nqbins])
#        for k in range(self.nrep):
#            for j in range(self.nqbins):
#                for i in range(self.nebins):
#                    #visits[k,i,j] = self.visits2d[i,j,k]
#                    reduced_energy[k,i,j] = self.binenergy[i] / (self.Tlist[k]*self.k_B)
        for j in range(self.nqbins):
            reduced_energy[:,:,j] = self.binenergy[np.newaxis,:] / (self.Tlist[:,np.newaxis]*self.k_B)
                    
        visits = self.visits2d
        visits = np.reshape( visits, [nreps, nbins ]) 
        reduced_energy = np.reshape( reduced_energy, [nreps, nbins])           
        self.logP = np.where( visits != 0, np.log( visits.astype(float) ), 0 )

        
        from wham_potential import WhamPotential
        whampot = WhamPotential( self.logP, reduced_energy )
        
        nvar = nbins + nreps
        X = np.random.rand(nvar)
        print "initial energy", whampot.getEnergy(X)
        try: 
            from pygmin.optimize import mylbfgs as quench
            ret = quench(X, whampot, iprint=10, maxstep = 1e4)
        except ImportError:
            from pygmin.optimize import lbfgs_scipy as quench
            ret = quench(X, whampot)            

        print "quenched energy", ret.energy
        
        global_min = False
        if global_min:
            from pygmin.basinhopping import BasinHopping
            from pygmin.takestep.displace import RandomDisplacement
            takestep = RandomDisplacement(stepsize=10.)
            takestep.useAdaptiveStep()
            takestep.adaptive_class.f = 2.
            bh = BasinHopping(X, whampot, takestep)
            bh.run(1000)
        
        
        #self.logn_Eq = zeros([nebins,nqbins], float64)
        X = ret.coords
        self.logn_Eq = X[nreps:]
        self.w_i_final = X[:nreps]
        
        self.logn_Eq = np.reshape(self.logn_Eq, [nebins, nqbins])
        self.logn_Eq = np.where( self.visits2d.sum(0) == 0, self.LOGMIN, self.logn_Eq )
    def minimize(self):
        #shape(visits2d) is now (nqbins, nebins, nreps)
        #we need it to be (nreps, nqbins*nebins)
        #first reorder indices
        nreps = self.nrep
        nebins = self.nebins
        nqbins = self.nqbins
        nbins = self.nebins * self.nqbins
        #visits = np.zeros([nreps, nebins, nqbins], np.integer)
        reduced_energy = np.zeros([nreps, nebins, nqbins])
        #        for k in range(self.nrep):
        #            for j in range(self.nqbins):
        #                for i in range(self.nebins):
        #                    #visits[k,i,j] = self.visits2d[i,j,k]
        #                    reduced_energy[k,i,j] = self.binenergy[i] / (self.Tlist[k]*self.k_B)
        for j in range(self.nqbins):
            reduced_energy[:, :, j] = self.binenergy[np.newaxis, :] / (
                self.Tlist[:, np.newaxis] * self.k_B)

        visits = self.visits2d
        visits = np.reshape(visits, [nreps, nbins])
        reduced_energy = np.reshape(reduced_energy, [nreps, nbins])
        self.logP = np.where(visits != 0, np.log(visits.astype(float)), 0)

        from wham_potential import WhamPotential
        whampot = WhamPotential(self.logP, reduced_energy)

        nvar = nbins + nreps
        X = np.random.rand(nvar)
        from wham_utils import lbfgs_scipy
        ret = lbfgs_scipy(X, self.whampot)
        #        print "initial energy", whampot.getEnergy(X)
        #        try:
        #            from pele.optimize import mylbfgs as quench
        #            ret = quench(X, whampot, iprint=10, maxstep = 1e4)
        #        except ImportError:
        #            from pele.optimize import lbfgs_scipy as quench
        #            ret = quench(X, whampot)

        print "quenched energy", ret.energy

        #self.logn_Eq = zeros([nebins,nqbins], float64)
        X = ret.coords
        self.logn_Eq = X[nreps:]
        self.w_i_final = X[:nreps]

        self.logn_Eq = np.reshape(self.logn_Eq, [nebins, nqbins])
        self.logn_Eq = np.where(
            self.visits2d.sum(0) == 0, self.LOGMIN, self.logn_Eq)
Example #5
0
    def globalMinimization(self):
        """
        in experimentation i've never been able to find more than
        one minimum
        """
        nreps = self.nrep
        nbins = self.nebins
        visitsT = (self.visits1d)
        #print "min vis", np.min(visitsT)
        self.logP = np.where(visitsT != 0, np.log(visitsT), 0)
        #print "minlogp", np.min(self.logP)
        self.reduced_energy = self.binenergy[np.newaxis, :] / (
            self.Tlist[:, np.newaxis] * self.k_B)

        self.whampot = WhamPotential(self.logP, self.reduced_energy)

        X = np.random.rand(nreps + nbins)
        E = self.whampot.getEnergy(X)
        print "energy", E

        print "quenching"
        from pygmin.optimize import lbfgs_scipy as quench
        ret = quench(X, self.whampot)
        print "quench energy", ret.energy

        from pygmin.basinhopping import BasinHopping
        from pygmin.takestep.displace import RandomDisplacement
        takestep = RandomDisplacement(stepsize=10)
        takestep.useAdaptiveStep()
        takestep.adaptive_class.f = 1.5  #i have no idea what a good stepsize should be
        bh = BasinHopping(X, self.whampot, takestep)

        import matplotlib.pyplot as plt
        for i in range(10):
            bh.run(2000)
            self.logn_E = bh.coords[nreps:]
            cvdata = self.calc_Cv(400)
            plt.plot(cvdata[:, 0], cvdata[:, 5], '-')
        plt.show()

        X = bh.coords
        self.logn_E = X[nreps:]
        self.w_i_final = X[:nreps]