Line data Source code
1 : /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 : Copyright (c) 2014-2023 The plumed team
3 : (see the PEOPLE file at the root of the distribution for a list of names)
4 :
5 : See http://www.plumed.org for more information.
6 :
7 : This file is part of plumed, version 2.
8 :
9 : plumed is free software: you can redistribute it and/or modify
10 : it under the terms of the GNU Lesser General Public License as published by
11 : the Free Software Foundation, either version 3 of the License, or
12 : (at your option) any later version.
13 :
14 : plumed is distributed in the hope that it will be useful,
15 : but WITHOUT ANY WARRANTY; without even the implied warranty of
16 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 : GNU Lesser General Public License for more details.
18 :
19 : You should have received a copy of the GNU Lesser General Public License
20 : along with plumed. If not, see <http://www.gnu.org/licenses/>.
21 : +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
22 : #include "Function.h"
23 : #include "tools/Communicator.h"
24 : #include "core/ActionRegister.h"
25 : #include "core/PlumedMain.h"
26 :
27 : namespace PLMD {
28 : namespace function {
29 :
30 : //+PLUMEDOC FUNCTION ENSEMBLE
31 : /*
32 : Calculates the replica averaging of a collective variable over multiple replicas.
33 :
34 : Each collective variable is averaged separately and stored in a component labelled <em>label</em>.cvlabel.
35 :
36 : \par Examples
37 :
38 : The following input tells plumed to calculate the distance between atoms 3 and 5
39 : and the average it over the available replicas.
40 : \plumedfile
41 : dist: DISTANCE ATOMS=3,5
42 : ens: ENSEMBLE ARG=dist
43 : PRINT ARG=dist,ens.dist
44 : \endplumedfile
45 :
46 : */
47 : //+ENDPLUMEDOC
48 :
49 :
50 : class Ensemble :
51 : public Function
52 : {
53 : unsigned ens_dim;
54 : unsigned my_repl;
55 : unsigned narg;
56 : bool master;
57 : bool do_reweight;
58 : bool do_moments;
59 : bool do_central;
60 : bool do_powers;
61 : double kbt;
62 : double moment;
63 : double power;
64 : public:
65 : explicit Ensemble(const ActionOptions&);
66 : std::string getOutputComponentDescription( const std::string& cname, const Keywords& keys ) const override ;
67 : void calculate() override;
68 : static void registerKeywords(Keywords& keys);
69 : };
70 :
71 :
72 : PLUMED_REGISTER_ACTION(Ensemble,"ENSEMBLE")
73 :
74 29 : void Ensemble::registerKeywords(Keywords& keys) {
75 29 : Function::registerKeywords(keys);
76 58 : keys.addFlag("REWEIGHT",false,"simple REWEIGHT using the latest ARG as energy");
77 58 : keys.addFlag("CENTRAL",false,"calculate a central moment instead of a standard moment");
78 58 : keys.add("optional","TEMP","the system temperature - this is only needed if you are reweighting");
79 58 : keys.add("optional","MOMENT","the moment you want to calculate in alternative to the mean or the variance");
80 58 : keys.add("optional","POWER","the power of the mean (and moment)");
81 29 : ActionWithValue::useCustomisableComponents(keys);
82 29 : }
83 :
84 27 : Ensemble::Ensemble(const ActionOptions&ao):
85 : Action(ao),
86 : Function(ao),
87 27 : do_reweight(false),
88 27 : do_moments(false),
89 27 : do_central(false),
90 27 : do_powers(false),
91 27 : kbt(-1.0),
92 27 : moment(0),
93 27 : power(0)
94 : {
95 27 : parseFlag("REWEIGHT", do_reweight);
96 27 : if(do_reweight) {
97 12 : kbt=getkBT();
98 12 : if(kbt==0.0) error("Unless the MD engine passes the temperature to plumed, with REWEIGHT you must specify TEMP");
99 30 : } else { double temp=0.0; parse("TEMP",temp); }
100 :
101 27 : parse("MOMENT",moment);
102 27 : if(moment==1) error("MOMENT can be any number but for 0 and 1");
103 27 : if(moment!=0) do_moments=true;
104 27 : parseFlag("CENTRAL", do_central);
105 27 : if(!do_moments&&do_central) error("To calculate a CENTRAL moment you need to define for which MOMENT");
106 :
107 27 : parse("POWER",power);
108 27 : if(power==1) error("POWER can be any number but for 0 and 1");
109 27 : if(power!=0) do_powers=true;
110 :
111 27 : checkRead();
112 :
113 27 : master = (comm.Get_rank()==0);
114 27 : ens_dim=0;
115 27 : my_repl=0;
116 27 : if(master) {
117 17 : ens_dim=multi_sim_comm.Get_size();
118 17 : my_repl=multi_sim_comm.Get_rank();
119 : }
120 27 : comm.Bcast(ens_dim,0);
121 27 : comm.Bcast(my_repl,0);
122 27 : if(ens_dim<2) log.printf("WARNING: ENSEMBLE with one replica is not doing any averaging!\n");
123 :
124 : // prepare output components, the number depending on reweighing or not
125 27 : narg = getNumberOfArguments();
126 27 : if(do_reweight) narg--;
127 :
128 : // these are the averages
129 3044 : for(unsigned i=0; i<narg; i++) {
130 3017 : std::string s=getPntrToArgument(i)->getName();
131 3017 : addComponentWithDerivatives(s);
132 3017 : getPntrToComponent(i)->setNotPeriodic();
133 : }
134 : // these are the moments
135 27 : if(do_moments) {
136 0 : for(unsigned i=0; i<narg; i++) {
137 0 : std::string s=getPntrToArgument(i)->getName()+"_m";
138 0 : addComponentWithDerivatives(s);
139 0 : getPntrToComponent(i+narg)->setNotPeriodic();
140 : }
141 : }
142 :
143 27 : log.printf(" averaging over %u replicas.\n", ens_dim);
144 27 : if(do_reweight) log.printf(" doing simple REWEIGHT using the latest ARGUMENT as energy.\n");
145 27 : if(do_moments&&!do_central) log.printf(" calculating also the %lf standard moment\n", moment);
146 27 : if(do_moments&&do_central) log.printf(" calculating also the %lf central moment\n", moment);
147 27 : if(do_powers) log.printf(" calculating the %lf power of the mean (and moment)\n", power);
148 27 : }
149 :
150 0 : std::string Ensemble::getOutputComponentDescription( const std::string& cname, const Keywords& keys ) const {
151 0 : for(unsigned i=0; i<getNumberOfArguments(); ++i) {
152 0 : if( cname==getPntrToArgument(i)->getName() ) return "the average for argument " + cname;
153 0 : if( cname==getPntrToArgument(i)->getName() + "_m" ) return "the moment for argument " + cname;
154 : }
155 0 : plumed_error(); return "";
156 : }
157 :
158 :
159 125 : void Ensemble::calculate() {
160 : double norm = 0.0;
161 125 : double fact = 0.0;
162 :
163 : // calculate the weights either from BIAS
164 125 : if(do_reweight) {
165 : std::vector<double> bias;
166 0 : bias.resize(ens_dim);
167 0 : if(master) {
168 0 : bias[my_repl] = getArgument(narg);
169 0 : if(ens_dim>1) multi_sim_comm.Sum(&bias[0], ens_dim);
170 : }
171 0 : comm.Sum(&bias[0], ens_dim);
172 0 : const double maxbias = *(std::max_element(bias.begin(), bias.end()));
173 0 : for(unsigned i=0; i<ens_dim; ++i) {
174 0 : bias[i] = exp((bias[i]-maxbias)/kbt);
175 0 : norm += bias[i];
176 : }
177 0 : fact = bias[my_repl]/norm;
178 : // or arithmetic ones
179 : } else {
180 125 : norm = static_cast<double>(ens_dim);
181 125 : fact = 1.0/norm;
182 : }
183 :
184 125 : const double fact_kbt = fact/kbt;
185 :
186 125 : std::vector<double> mean(narg);
187 125 : std::vector<double> dmean(narg,fact);
188 : // calculate the mean
189 125 : if(master) {
190 2106 : for(unsigned i=0; i<narg; ++i) mean[i] = fact*getArgument(i);
191 99 : if(ens_dim>1) multi_sim_comm.Sum(&mean[0], narg);
192 : }
193 125 : comm.Sum(&mean[0], narg);
194 :
195 : std::vector<double> v_moment, dv_moment;
196 : // calculate other moments
197 125 : if(do_moments) {
198 0 : v_moment.resize(narg);
199 0 : dv_moment.resize(narg);
200 : // standard moment
201 0 : if(!do_central) {
202 0 : if(master) {
203 0 : for(unsigned i=0; i<narg; ++i) {
204 0 : const double tmp = fact*std::pow(getArgument(i),moment-1);
205 0 : v_moment[i] = tmp*getArgument(i);
206 0 : dv_moment[i] = moment*tmp;
207 : }
208 0 : if(ens_dim>1) multi_sim_comm.Sum(&v_moment[0], narg);
209 : } else {
210 0 : for(unsigned i=0; i<narg; ++i) {
211 0 : const double tmp = fact*std::pow(getArgument(i),moment-1);
212 0 : dv_moment[i] = moment*tmp;
213 : }
214 : }
215 : // central moment
216 : } else {
217 0 : if(master) {
218 0 : for(unsigned i=0; i<narg; ++i) {
219 0 : const double tmp = std::pow(getArgument(i)-mean[i],moment-1);
220 0 : v_moment[i] = fact*tmp*(getArgument(i)-mean[i]);
221 0 : dv_moment[i] = moment*tmp*(fact-fact/norm);
222 : }
223 0 : if(ens_dim>1) multi_sim_comm.Sum(&v_moment[0], narg);
224 : } else {
225 0 : for(unsigned i=0; i<narg; ++i) {
226 0 : const double tmp = std::pow(getArgument(i)-mean[i],moment-1);
227 0 : dv_moment[i] = moment*tmp*(fact-fact/norm);
228 : }
229 : }
230 : }
231 0 : comm.Sum(&v_moment[0], narg);
232 : }
233 :
234 : // calculate powers of moments
235 125 : if(do_powers) {
236 72 : for(unsigned i=0; i<narg; ++i) {
237 48 : const double tmp1 = std::pow(mean[i],power-1);
238 48 : mean[i] *= tmp1;
239 48 : dmean[i] *= power*tmp1;
240 48 : if(do_moments) {
241 0 : const double tmp2 = std::pow(v_moment[i],power-1);
242 0 : v_moment[i] *= tmp2;
243 0 : dv_moment[i] *= power*tmp2;
244 : }
245 : }
246 : }
247 :
248 : // set components
249 3358 : for(unsigned i=0; i<narg; ++i) {
250 : // set mean
251 3233 : Value* v=getPntrToComponent(i);
252 3233 : v->set(mean[i]);
253 3233 : setDerivative(v, i, dmean[i]);
254 3233 : if(do_reweight) {
255 0 : const double w_tmp = fact_kbt*(getArgument(i) - mean[i]);
256 0 : setDerivative(v, narg, w_tmp);
257 : }
258 3233 : if(do_moments) {
259 : // set moments
260 0 : Value* u=getPntrToComponent(i+narg);
261 0 : u->set(v_moment[i]);
262 0 : setDerivative(u, i, dv_moment[i]);
263 0 : if(do_reweight) {
264 0 : const double w_tmp = fact_kbt*(pow(getArgument(i),moment) - v_moment[i]);
265 0 : setDerivative(u, narg, w_tmp);
266 : }
267 : }
268 : }
269 125 : }
270 :
271 : }
272 : }
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