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46 #include "gromacs/commandline/viewit.h"
47 #include "gromacs/correlationfunctions/expfit.h"
48 #include "gromacs/correlationfunctions/integrate.h"
49 #include "gromacs/fft/fft.h"
50 #include "gromacs/fileio/xvgr.h"
51 #include "gromacs/gmxana/gmx_ana.h"
52 #include "gromacs/gmxana/gstat.h"
53 #include "gromacs/math/gmxcomplex.h"
54 #include "gromacs/math/utilities.h"
55 #include "gromacs/utility/arraysize.h"
56 #include "gromacs/utility/fatalerror.h"
57 #include "gromacs/utility/futil.h"
58 #include "gromacs/utility/pleasecite.h"
59 #include "gromacs/utility/smalloc.h"
61 /* Determines at which point in the array the fit should start */
62 static int calc_nbegin(int nx, real x[], real tbegin)
66 /* Assume input x is sorted */
67 for (nbegin = 0; (nbegin < nx) && (x[nbegin] <= tbegin); nbegin++)
69 // Deliberately left empty
71 if ((nbegin == nx) || (nbegin == 0))
73 gmx_fatal(FARGS, "Begin time %f not in x-domain [%f through %f]\n", tbegin, x[0], x[nx - 1]);
76 /* Take the one closest to tbegin */
77 if (std::abs(x[nbegin] - tbegin) > std::abs(x[nbegin - 1] - tbegin))
82 printf("nbegin = %d, x[nbegin] = %g, tbegin = %g\n", nbegin, x[nbegin], tbegin);
88 numerical_deriv(int nx, real x[], const real y[], const real fity[], real combined[], real dy[], real tendInt, int nsmooth)
91 int i, nbegin, i0, i1;
92 real fac, fx, fy, integralSmth;
94 nbegin = calc_nbegin(nx, x, tendInt);
97 for (i = 0; (i < nbegin); i++)
101 fac = y[nbegin] / fity[nbegin];
102 printf("scaling fitted curve by %g\n", fac);
103 for (i = nbegin; (i < nx); i++)
105 combined[i] = fity[i] * fac;
110 i0 = std::max(0, nbegin);
111 i1 = std::min(nx - 1, nbegin + nsmooth);
112 printf("Making smooth transition from %d through %d\n", i0, i1);
113 for (i = 0; (i < i0); i++)
117 for (i = i0; (i <= i1); i++)
119 fx = static_cast<real>(i1 - i) / (i1 - i0);
120 fy = static_cast<real>(i - i0) / (i1 - i0);
123 fprintf(debug, "x: %g factors for smoothing: %10g %10g\n", x[i], fx, fy);
125 combined[i] = fx * y[i] + fy * fity[i];
127 for (i = i1 + 1; (i < nx); i++)
129 combined[i] = fity[i];
133 tmpfp = gmx_ffopen("integral_smth.xvg", "w");
134 integralSmth = print_and_integrate(tmpfp, nx, x[1] - x[0], combined, nullptr, 1);
135 printf("SMOOTH integral = %10.5e\n", integralSmth);
137 dy[0] = (combined[1] - combined[0]) / (x[1] - x[0]);
138 for (i = 1; (i < nx - 1); i++)
140 dy[i] = (combined[i + 1] - combined[i - 1]) / (x[i + 1] - x[i - 1]);
142 dy[nx - 1] = (combined[nx - 1] - combined[nx - 2]) / (x[nx - 1] - x[nx - 2]);
144 for (i = 0; (i < nx); i++)
152 static void do_four(const char* fn,
159 const gmx_output_env_t* oenv)
162 t_complex *tmp, gw, hw, kw;
164 real fac, nu, dt, maxeps, numax;
169 /*while ((dy[nx-1] == 0.0) && (nx > 0))
173 gmx_fatal(FARGS, "Empty dataset in %s, line %d!", __FILE__, __LINE__);
183 printf("Doing FFT of %d points\n", nnx);
184 for (i = 0; (i < nx); i++)
188 if ((fftcode = gmx_fft_init_1d_real(&fft, nnx, GMX_FFT_FLAG_NONE)) != 0)
190 gmx_fatal(FARGS, "gmx_fft_init_1d_real returned %d", fftcode);
192 if ((fftcode = gmx_fft_1d_real(fft, GMX_FFT_COMPLEX_TO_REAL, tmp, tmp)) != 0)
194 gmx_fatal(FARGS, "gmx_fft_1d_real returned %d", fftcode);
196 gmx_fft_destroy(fft);
200 fac = (eps0 - 1) / tmp[0].re;
204 fac = ((eps0 - 1) / (2 * epsRF + eps0)) / tmp[0].re;
206 fp = xvgropen(fn, "Epsilon(\\8w\\4)", "Freq. (GHz)", "eps", oenv);
207 cp = xvgropen(cn, "Cole-Cole plot", "Eps'", "Eps''", oenv);
210 for (i = 0; (i < nxsav); i++)
214 kw.re = 1 + fac * tmp[i].re;
215 kw.im = 1 + fac * tmp[i].im;
219 gw = rcmul(fac, tmp[i]);
220 hw = rcmul(2 * epsRF, gw);
228 nu = (i + 1) * 1000.0 / (nnx * dt);
235 fprintf(fp, "%10.5e %10.5e %10.5e\n", nu, kw.re, kw.im);
236 fprintf(cp, "%10.5e %10.5e\n", kw.re, kw.im);
238 printf("MAXEPS = %10.5e at frequency %10.5e GHz (tauD = %8.1f ps)\n", maxeps, numax,
239 1000 / (2 * M_PI * numax));
245 int gmx_dielectric(int argc, char* argv[])
247 const char* desc[] = {
248 "[THISMODULE] calculates frequency dependent dielectric constants",
249 "from the autocorrelation function of the total dipole moment in",
250 "your simulation. This ACF can be generated by [gmx-dipoles].",
251 "The functional forms of the available functions are:",
253 " * One parameter: y = [EXP]-a[SUB]1[sub] x[exp],",
254 " * Two parameters: y = a[SUB]2[sub] [EXP]-a[SUB]1[sub] x[exp],",
255 " * Three parameters: y = a[SUB]2[sub] [EXP]-a[SUB]1[sub] x[exp] + (1 - ",
256 " a[SUB]2[sub]) [EXP]-a[SUB]3[sub] x[exp].",
258 "Start values for the fit procedure can be given on the command line.",
259 "It is also possible to fix parameters at their start value, use [TT]-fix[tt]",
260 "with the number of the parameter you want to fix.",
262 "Three output files are generated, the first contains the ACF,",
263 "an exponential fit to it with 1, 2 or 3 parameters, and the",
264 "numerical derivative of the combination data/fit.",
265 "The second file contains the real and imaginary parts of the",
266 "frequency-dependent dielectric constant, the last gives a plot",
267 "known as the Cole-Cole plot, in which the imaginary",
268 "component is plotted as a function of the real component.",
269 "For a pure exponential relaxation (Debye relaxation) the latter",
270 "plot should be one half of a circle."
272 t_filenm fnm[] = { { efXVG, "-f", "dipcorr", ffREAD },
273 { efXVG, "-d", "deriv", ffWRITE },
274 { efXVG, "-o", "epsw", ffWRITE },
275 { efXVG, "-c", "cole", ffWRITE } };
276 #define NFILE asize(fnm)
277 gmx_output_env_t* oenv;
278 int i, j, nx, ny, nxtail, eFitFn, nfitparm;
279 real dt, integral, fitintegral, fac, rffac;
283 const char* legend[] = { "Correlation", "Std. Dev.", "Fit", "Combined", "Derivative" };
284 static int fix = 0, bX = 1, nsmooth = 3;
285 static real tendInt = 5.0, tbegin = 5.0, tend = 500.0;
286 static real A = 0.5, tau1 = 10.0, tau2 = 1.0, eps0 = 80, epsRF = 78.5, tail = 500.0;
293 "use first column as [IT]x[it]-axis rather than first data set" },
298 "Time to end the integration of the data and start to use the fit" },
299 { "-bfit", FALSE, etREAL, { &tbegin }, "Begin time of fit" },
300 { "-efit", FALSE, etREAL, { &tend }, "End time of fit" },
301 { "-tail", FALSE, etREAL, { &tail }, "Length of function including data and tail from fit" },
302 { "-A", FALSE, etREAL, { &A }, "Start value for fit parameter A" },
303 { "-tau1", FALSE, etREAL, { &tau1 }, "Start value for fit parameter [GRK]tau[grk]1" },
304 { "-tau2", FALSE, etREAL, { &tau2 }, "Start value for fit parameter [GRK]tau[grk]2" },
305 { "-eps0", FALSE, etREAL, { &eps0 }, "[GRK]epsilon[grk]0 of your liquid" },
310 "[GRK]epsilon[grk] of the reaction field used in your simulation. A value of 0 means "
316 "Fix parameters at their start values, A (2), tau1 (1), or tau2 (4)" },
317 { "-ffn", FALSE, etENUM, { s_ffn }, "Fit function" },
318 { "-nsmooth", FALSE, etINT, { &nsmooth }, "Number of points for smoothing" }
321 if (!parse_common_args(&argc, argv, PCA_CAN_TIME | PCA_CAN_VIEW, NFILE, fnm, asize(pa), pa,
322 asize(desc), desc, 0, nullptr, &oenv))
326 please_cite(stdout, "Spoel98a");
327 printf("WARNING: non-polarizable models can never yield an infinite\n"
328 "dielectric constant that is different from 1. This is incorrect\n"
329 "in the reference given above (Spoel98a).\n\n");
332 nx = read_xvg(opt2fn("-f", NFILE, fnm), &yd, &ny);
333 dt = yd[0][1] - yd[0][0];
334 nxtail = std::min(static_cast<int>(tail / dt), nx);
336 printf("Read data set containing %d colums and %d rows\n", ny, nx);
337 printf("Assuming (from data) that timestep is %g, nxtail = %d\n", dt, nxtail);
339 for (i = 0; (i < ny); i++)
341 snew(y[i], std::max(nx, nxtail));
343 for (i = 0; (i < nx); i++)
346 for (j = 1; (j < ny); j++)
353 for (i = nx; (i < nxtail); i++)
355 y[0][i] = dt * i + y[0][0];
356 for (j = 1; (j < ny); j++)
365 /* We have read a file WITHOUT standard deviations, so we make our own... */
368 printf("Creating standard deviation numbers ...\n");
372 for (i = 0; (i < nx); i++)
378 eFitFn = sffn2effn(s_ffn);
379 nfitparm = effnNparams(eFitFn);
396 integral = print_and_integrate(nullptr, calc_nbegin(nx, y[0], tbegin), dt, y[1], nullptr, 1);
397 integral += do_lmfit(nx, y[1], y[2], dt, y[0], tbegin, tend, oenv, TRUE, eFitFn, fitparms, fix, nullptr);
398 for (i = 0; i < nx; i++)
400 y[3][i] = fit_function(eFitFn, fitparms, y[0][i]);
405 /* This means infinity! */
411 lambda = (eps0 - 1.0) / (2 * epsRF - 1.0);
412 rffac = (2 * epsRF + eps0) / (2 * epsRF + 1);
414 printf("DATA INTEGRAL: %5.1f, tauD(old) = %5.1f ps, "
415 "tau_slope = %5.1f, tau_slope,D = %5.1f ps\n",
416 integral, integral * rffac, fitparms[0], fitparms[0] * rffac);
418 printf("tau_D from tau1 = %8.3g , eps(Infty) = %8.3f\n", fitparms[0] * (1 + fitparms[1] * lambda),
419 1 + ((1 - fitparms[1]) * (eps0 - 1)) / (1 + fitparms[1] * lambda));
421 fitintegral = numerical_deriv(nx, y[0], y[1], y[3], y[4], y[5], tendInt, nsmooth);
422 printf("FIT INTEGRAL (tau_M): %5.1f, tau_D = %5.1f\n", fitintegral, fitintegral * rffac);
424 /* Now we have the negative gradient of <Phi(0) Phi(t)> */
425 write_xvg(opt2fn("-d", NFILE, fnm), "Data", nx - 1, 6, y, legend, oenv);
427 /* Do FFT and analysis */
428 do_four(opt2fn("-o", NFILE, fnm), opt2fn("-c", NFILE, fnm), nx - 1, y[0], y[5], eps0, epsRF, oenv);
430 do_view(oenv, opt2fn("-o", NFILE, fnm), "-nxy");
431 do_view(oenv, opt2fn("-c", NFILE, fnm), nullptr);
432 do_view(oenv, opt2fn("-d", NFILE, fnm), "-nxy");