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44 #include "gromacs/commandline/pargs.h"
45 #include "gromacs/fileio/trxio.h"
46 #include "gromacs/fileio/xvgr.h"
47 #include "gromacs/gmxana/gmx_ana.h"
48 #include "gromacs/gmxana/gstat.h"
49 #include "gromacs/legacyheaders/macros.h"
50 #include "gromacs/legacyheaders/typedefs.h"
51 #include "gromacs/legacyheaders/viewit.h"
52 #include "gromacs/math/units.h"
53 #include "gromacs/math/vec.h"
54 #include "gromacs/pbcutil/pbc.h"
55 #include "gromacs/pbcutil/rmpbc.h"
56 #include "gromacs/topology/index.h"
57 #include "gromacs/utility/cstringutil.h"
58 #include "gromacs/utility/fatalerror.h"
59 #include "gromacs/utility/futil.h"
60 #include "gromacs/utility/smalloc.h"
67 /****************************************************************************/
68 /* This program calculates the partial density across the box. */
69 /* Peter Tieleman, Mei 1995 */
70 /****************************************************************************/
72 /* used for sorting the list */
73 int compare(void *a, void *b)
75 t_electron *tmp1, *tmp2;
76 tmp1 = (t_electron *)a; tmp2 = (t_electron *)b;
78 return strcmp(tmp1->atomname, tmp2->atomname);
81 int get_electrons(t_electron **eltab, const char *fn)
83 char buffer[256]; /* to read in a line */
84 char tempname[80]; /* buffer to hold name */
88 int nr; /* number of atomstypes to read */
91 if (!(in = gmx_ffopen(fn, "r")))
93 gmx_fatal(FARGS, "Couldn't open %s. Exiting.\n", fn);
96 if (NULL == fgets(buffer, 255, in))
98 gmx_fatal(FARGS, "Error reading from file %s", fn);
101 if (sscanf(buffer, "%d", &nr) != 1)
103 gmx_fatal(FARGS, "Invalid number of atomtypes in datafile\n");
108 for (i = 0; i < nr; i++)
110 if (fgets(buffer, 255, in) == NULL)
112 gmx_fatal(FARGS, "reading datafile. Check your datafile.\n");
114 if (sscanf(buffer, "%s = %d", tempname, &tempnr) != 2)
116 gmx_fatal(FARGS, "Invalid line in datafile at line %d\n", i+1);
118 (*eltab)[i].nr_el = tempnr;
119 (*eltab)[i].atomname = gmx_strdup(tempname);
124 fprintf(stderr, "Sorting list..\n");
125 qsort ((void*)*eltab, nr, sizeof(t_electron),
126 (int(*)(const void*, const void*))compare);
131 void center_coords(t_atoms *atoms, atom_id *index_center, int ncenter,
132 matrix box, rvec x0[])
136 rvec com, shift, box_center;
140 for (k = 0; (k < ncenter); k++)
145 gmx_fatal(FARGS, "Index %d refers to atom %d, which is larger than natoms (%d).",
146 k+1, i+1, atoms->nr);
148 mm = atoms->atom[i].m;
150 for (m = 0; (m < DIM); m++)
152 com[m] += mm*x0[i][m];
155 for (m = 0; (m < DIM); m++)
159 calc_box_center(ecenterDEF, box, box_center);
160 rvec_sub(com, box_center, shift);
162 /* Important - while the center was calculated based on a group, we should move all atoms */
163 for (i = 0; (i < atoms->nr); i++)
165 rvec_dec(x0[i], shift);
169 void calc_electron_density(const char *fn, atom_id **index, int gnx[],
170 double ***slDensity, int *nslices, t_topology *top,
172 int axis, int nr_grps, real *slWidth,
173 t_electron eltab[], int nr, gmx_bool bCenter,
174 atom_id *index_center, int ncenter,
175 gmx_bool bRelative, const output_env_t oenv)
177 rvec *x0; /* coordinates without pbc */
178 matrix box; /* box (3x3) */
180 int natoms; /* nr. atoms in trj */
182 int i, n, /* loop indices */
183 nr_frames = 0, /* number of frames */
184 slice; /* current slice */
185 t_electron *found; /* found by bsearch */
186 t_electron sought; /* thingie thought by bsearch */
188 gmx_rmpbc_t gpbc = NULL;
193 if (axis < 0 || axis >= DIM)
195 gmx_fatal(FARGS, "Invalid axes. Terminating\n");
198 if ((natoms = read_first_x(oenv, &status, fn, &t, &x0, box)) == 0)
200 gmx_fatal(FARGS, "Could not read coordinates from statusfile\n");
207 *nslices = (int)(box[axis][axis] * 10); /* default value */
208 fprintf(stderr, "\nDividing the box in %d slices\n", *nslices);
211 snew(*slDensity, nr_grps);
212 for (i = 0; i < nr_grps; i++)
214 snew((*slDensity)[i], *nslices);
217 gpbc = gmx_rmpbc_init(&top->idef, ePBC, top->atoms.nr);
218 /*********** Start processing trajectory ***********/
221 gmx_rmpbc(gpbc, natoms, box, x0);
223 /* Translate atoms so the com of the center-group is in the
224 * box geometrical center.
228 center_coords(&top->atoms, index_center, ncenter, box, x0);
231 invvol = *nslices/(box[XX][XX]*box[YY][YY]*box[ZZ][ZZ]);
235 *slWidth = 1.0/(*nslices);
240 *slWidth = box[axis][axis]/(*nslices);
241 boxSz = box[axis][axis];
244 aveBox += box[axis][axis];
246 for (n = 0; n < nr_grps; n++)
248 for (i = 0; i < gnx[n]; i++) /* loop over all atoms in index file */
250 z = x0[index[n][i]][axis];
253 z += box[axis][axis];
255 while (z > box[axis][axis])
257 z -= box[axis][axis];
262 z = z/box[axis][axis];
265 /* determine which slice atom is in */
268 slice = floor( (z-(boxSz/2.0)) / (*slWidth) ) + *nslices/2;
272 slice = (z / (*slWidth));
275 sought.atomname = gmx_strdup(*(top->atoms.atomname[index[n][i]]));
277 /* now find the number of electrons. This is not efficient. */
278 found = (t_electron *)
279 bsearch((const void *)&sought,
280 (const void *)eltab, nr, sizeof(t_electron),
281 (int(*)(const void*, const void*))compare);
285 fprintf(stderr, "Couldn't find %s. Add it to the .dat file\n",
286 *(top->atoms.atomname[index[n][i]]));
290 (*slDensity)[n][slice] += (found->nr_el -
291 top->atoms.atom[index[n][i]].q)*invvol;
293 free(sought.atomname);
298 while (read_next_x(oenv, status, &t, x0, box));
299 gmx_rmpbc_done(gpbc);
301 /*********** done with status file **********/
304 /* slDensity now contains the total number of electrons per slice, summed
305 over all frames. Now divide by nr_frames and volume of slice
308 fprintf(stderr, "\nRead %d frames from trajectory. Counting electrons\n",
314 *slWidth = aveBox/(*nslices);
317 for (n = 0; n < nr_grps; n++)
319 for (i = 0; i < *nslices; i++)
321 (*slDensity)[n][i] /= nr_frames;
325 sfree(x0); /* free memory used by coordinate array */
328 void calc_density(const char *fn, atom_id **index, int gnx[],
329 double ***slDensity, int *nslices, t_topology *top, int ePBC,
330 int axis, int nr_grps, real *slWidth, gmx_bool bCenter,
331 atom_id *index_center, int ncenter,
332 gmx_bool bRelative, const output_env_t oenv)
334 rvec *x0; /* coordinates without pbc */
335 matrix box; /* box (3x3) */
337 int natoms; /* nr. atoms in trj */
339 int **slCount, /* nr. of atoms in one slice for a group */
340 i, j, n, /* loop indices */
342 nr_frames = 0, /* number of frames */
343 slice; /* current slice */
347 char *buf; /* for tmp. keeping atomname */
348 gmx_rmpbc_t gpbc = NULL;
350 if (axis < 0 || axis >= DIM)
352 gmx_fatal(FARGS, "Invalid axes. Terminating\n");
355 if ((natoms = read_first_x(oenv, &status, fn, &t, &x0, box)) == 0)
357 gmx_fatal(FARGS, "Could not read coordinates from statusfile\n");
364 *nslices = (int)(box[axis][axis] * 10); /* default value */
365 fprintf(stderr, "\nDividing the box in %d slices\n", *nslices);
368 snew(*slDensity, nr_grps);
369 for (i = 0; i < nr_grps; i++)
371 snew((*slDensity)[i], *nslices);
374 gpbc = gmx_rmpbc_init(&top->idef, ePBC, top->atoms.nr);
375 /*********** Start processing trajectory ***********/
378 gmx_rmpbc(gpbc, natoms, box, x0);
380 /* Translate atoms so the com of the center-group is in the
381 * box geometrical center.
385 center_coords(&top->atoms, index_center, ncenter, box, x0);
388 invvol = *nslices/(box[XX][XX]*box[YY][YY]*box[ZZ][ZZ]);
392 *slWidth = 1.0/(*nslices);
397 *slWidth = box[axis][axis]/(*nslices);
398 boxSz = box[axis][axis];
401 aveBox += box[axis][axis];
403 for (n = 0; n < nr_grps; n++)
405 for (i = 0; i < gnx[n]; i++) /* loop over all atoms in index file */
407 z = x0[index[n][i]][axis];
410 z += box[axis][axis];
412 while (z > box[axis][axis])
414 z -= box[axis][axis];
419 z = z/box[axis][axis];
422 /* determine which slice atom is in */
425 slice = floor( (z-(boxSz/2.0)) / (*slWidth) ) + *nslices/2;
429 slice = floor(z / (*slWidth));
432 /* Slice should already be 0<=slice<nslices, but we just make
433 * sure we are not hit by IEEE rounding errors since we do
434 * math operations after applying PBC above.
440 else if (slice >= *nslices)
445 (*slDensity)[n][slice] += top->atoms.atom[index[n][i]].m*invvol;
450 while (read_next_x(oenv, status, &t, x0, box));
451 gmx_rmpbc_done(gpbc);
453 /*********** done with status file **********/
456 /* slDensity now contains the total mass per slice, summed over all
457 frames. Now divide by nr_frames and volume of slice
460 fprintf(stderr, "\nRead %d frames from trajectory. Calculating density\n",
466 *slWidth = aveBox/(*nslices);
469 for (n = 0; n < nr_grps; n++)
471 for (i = 0; i < *nslices; i++)
473 (*slDensity)[n][i] /= nr_frames;
477 sfree(x0); /* free memory used by coordinate array */
480 void plot_density(double *slDensity[], const char *afile, int nslices,
481 int nr_grps, char *grpname[], real slWidth,
482 const char **dens_opt,
483 gmx_bool bCenter, gmx_bool bRelative, gmx_bool bSymmetrize,
484 const output_env_t oenv)
487 const char *title = NULL;
488 const char *xlabel = NULL;
489 const char *ylabel = NULL;
494 title = bSymmetrize ? "Symmetrized partial density" : "Partial density";
499 "Average relative position from center (nm)" :
500 "Relative position from center (nm)";
504 xlabel = bRelative ? "Average coordinate (nm)" : "Coordinate (nm)";
507 switch (dens_opt[0][0])
509 case 'm': ylabel = "Density (kg m\\S-3\\N)"; break;
510 case 'n': ylabel = "Number density (nm\\S-3\\N)"; break;
511 case 'c': ylabel = "Charge density (e nm\\S-3\\N)"; break;
512 case 'e': ylabel = "Electron density (e nm\\S-3\\N)"; break;
515 den = xvgropen(afile,
516 title, xlabel, ylabel, oenv);
518 xvgr_legend(den, nr_grps, (const char**)grpname, oenv);
520 for (slice = 0; (slice < nslices); slice++)
524 axispos = (slice - nslices/2.0 + 0.5) * slWidth;
528 axispos = (slice + 0.5) * slWidth;
530 fprintf(den, "%12g ", axispos);
531 for (n = 0; (n < nr_grps); n++)
535 ddd = (slDensity[n][slice]+slDensity[n][nslices-slice-1])*0.5;
539 ddd = slDensity[n][slice];
541 if (dens_opt[0][0] == 'm')
543 fprintf(den, " %12g", ddd*AMU/(NANO*NANO*NANO));
547 fprintf(den, " %12g", ddd);
556 int gmx_density(int argc, char *argv[])
558 const char *desc[] = {
559 "[THISMODULE] computes partial densities across the box, using an index file.[PAR]",
560 "For the total density of NPT simulations, use [gmx-energy] instead.",
563 "Option [TT]-center[tt] performs the histogram binning relative to the center",
564 "of an arbitrary group, in absolute box coordinates. If you are calculating",
565 "profiles along the Z axis box dimension bZ, output would be from -bZ/2 to",
566 "bZ/2 if you center based on the entire system.",
567 "Note that this behaviour has changed in GROMACS 5.0; earlier versions",
568 "merely performed a static binning in (0,bZ) and shifted the output. Now",
569 "we compute the center for each frame and bin in (-bZ/2,bZ/2).[PAR]",
571 "Option [TT]-symm[tt] symmetrizes the output around the center. This will",
572 "automatically turn on [TT]-center[tt] too.",
574 "Option [TT]-relative[tt] performs the binning in relative instead of absolute",
575 "box coordinates, and scales the final output with the average box dimension",
576 "along the output axis. This can be used in combination with [TT]-center[tt].[PAR]",
578 "Densities are in kg/m^3, and number densities or electron densities can also be",
579 "calculated. For electron densities, a file describing the number of",
580 "electrons for each type of atom should be provided using [TT]-ei[tt].",
581 "It should look like::",
584 " atomname = nrelectrons",
585 " atomname = nrelectrons",
587 "The first line contains the number of lines to read from the file.",
588 "There should be one line for each unique atom name in your system.",
589 "The number of electrons for each atom is modified by its atomic",
590 "partial charge.[PAR]",
592 "IMPORTANT CONSIDERATIONS FOR BILAYERS[PAR]",
593 "One of the most common usage scenarios is to calculate the density of various",
594 "groups across a lipid bilayer, typically with the z axis being the normal",
595 "direction. For short simulations, small systems, and fixed box sizes this",
596 "will work fine, but for the more general case lipid bilayers can be complicated.",
597 "The first problem that while both proteins and lipids have low volume",
598 "compressibility, lipids have quite high area compressiblity. This means the",
599 "shape of the box (thickness and area/lipid) will fluctuate substantially even",
600 "for a fully relaxed system. Since GROMACS places the box between the origin",
601 "and positive coordinates, this in turn means that a bilayer centered in the",
602 "box will move a bit up/down due to these fluctuations, and smear out your",
603 "profile. The easiest way to fix this (if you want pressure coupling) is",
604 "to use the [TT]-center[tt] option that calculates the density profile with",
605 "respect to the center of the box. Note that you can still center on the",
606 "bilayer part even if you have a complex non-symmetric system with a bilayer",
607 "and, say, membrane proteins - then our output will simply have more values",
608 "on one side of the (center) origin reference.[PAR]",
610 "Even the centered calculation will lead to some smearing out the output",
611 "profiles, as lipids themselves are compressed and expanded. In most cases",
612 "you probably want this (since it corresponds to macroscopic experiments),",
613 "but if you want to look at molecular details you can use the [TT]-relative[tt]",
614 "option to attempt to remove even more of the effects of volume fluctuations.[PAR]",
616 "Finally, large bilayers that are not subject to a surface tension will exhibit",
617 "undulatory fluctuations, where there are 'waves' forming in the system.",
618 "This is a fundamental property of the biological system, and if you are",
619 "comparing against experiments you likely want to include the undulation",
625 static const char *dens_opt[] =
626 { NULL, "mass", "number", "charge", "electron", NULL };
627 static int axis = 2; /* normal to memb. default z */
628 static const char *axtitle = "Z";
629 static int nslices = 50; /* nr of slices defined */
630 static int ngrps = 1; /* nr. of groups */
631 static gmx_bool bSymmetrize = FALSE;
632 static gmx_bool bCenter = FALSE;
633 static gmx_bool bRelative = FALSE;
636 { "-d", FALSE, etSTR, {&axtitle},
637 "Take the normal on the membrane in direction X, Y or Z." },
638 { "-sl", FALSE, etINT, {&nslices},
639 "Divide the box in this number of slices." },
640 { "-dens", FALSE, etENUM, {dens_opt},
642 { "-ng", FALSE, etINT, {&ngrps},
643 "Number of groups of which to compute densities." },
644 { "-center", FALSE, etBOOL, {&bCenter},
645 "Perform the binning relative to the center of the (changing) box. Useful for bilayers." },
646 { "-symm", FALSE, etBOOL, {&bSymmetrize},
647 "Symmetrize the density along the axis, with respect to the center. Useful for bilayers." },
648 { "-relative", FALSE, etBOOL, {&bRelative},
649 "Use relative coordinates for changing boxes and scale output by average dimensions." }
652 const char *bugs[] = {
653 "When calculating electron densities, atomnames are used instead of types. This is bad.",
656 double **density; /* density per slice */
657 real slWidth; /* width of one slice */
658 char *grpname_center; /* centering group name */
659 char **grpname; /* groupnames */
660 int nr_electrons; /* nr. electrons */
661 int ncenter; /* size of centering group */
662 int *ngx; /* sizes of groups */
663 t_electron *el_tab; /* tabel with nr. of electrons*/
664 t_topology *top; /* topology */
666 atom_id *index_center; /* index for centering group */
667 atom_id **index; /* indices for all groups */
670 t_filenm fnm[] = { /* files for g_density */
671 { efTRX, "-f", NULL, ffREAD },
672 { efNDX, NULL, NULL, ffOPTRD },
673 { efTPR, NULL, NULL, ffREAD },
674 { efDAT, "-ei", "electrons", ffOPTRD }, /* file with nr. of electrons */
675 { efXVG, "-o", "density", ffWRITE },
678 #define NFILE asize(fnm)
680 if (!parse_common_args(&argc, argv, PCA_CAN_VIEW | PCA_CAN_TIME,
681 NFILE, fnm, asize(pa), pa, asize(desc), desc, asize(bugs), bugs,
687 if (bSymmetrize && !bCenter)
689 fprintf(stderr, "Can not symmetrize without centering. Turning on -center\n");
693 axis = toupper(axtitle[0]) - 'X';
695 top = read_top(ftp2fn(efTPR, NFILE, fnm), &ePBC); /* read topology file */
696 if (dens_opt[0][0] == 'n')
698 for (i = 0; (i < top->atoms.nr); i++)
700 top->atoms.atom[i].m = 1;
703 else if (dens_opt[0][0] == 'c')
705 for (i = 0; (i < top->atoms.nr); i++)
707 top->atoms.atom[i].m = top->atoms.atom[i].q;
711 snew(grpname, ngrps);
718 "\nNote: that the center of mass is calculated inside the box without applying\n"
719 "any special periodicity. If necessary, it is your responsibility to first use\n"
720 "trjconv to make sure atoms in this group are placed in the right periodicity.\n\n"
721 "Select the group to center density profiles around:\n");
722 get_index(&top->atoms, ftp2fn_null(efNDX, NFILE, fnm), 1, &ncenter,
723 &index_center, &grpname_center);
730 fprintf(stderr, "\nSelect %d group%s to calculate density for:\n", ngrps, (ngrps > 1) ? "s" : "");
731 get_index(&top->atoms, ftp2fn_null(efNDX, NFILE, fnm), ngrps, ngx, index, grpname);
733 if (dens_opt[0][0] == 'e')
735 nr_electrons = get_electrons(&el_tab, ftp2fn(efDAT, NFILE, fnm));
736 fprintf(stderr, "Read %d atomtypes from datafile\n", nr_electrons);
738 calc_electron_density(ftp2fn(efTRX, NFILE, fnm), index, ngx, &density,
739 &nslices, top, ePBC, axis, ngrps, &slWidth, el_tab,
740 nr_electrons, bCenter, index_center, ncenter,
745 calc_density(ftp2fn(efTRX, NFILE, fnm), index, ngx, &density, &nslices, top,
746 ePBC, axis, ngrps, &slWidth, bCenter, index_center, ncenter,
750 plot_density(density, opt2fn("-o", NFILE, fnm),
751 nslices, ngrps, grpname, slWidth, dens_opt,
752 bCenter, bRelative, bSymmetrize, oenv);
754 do_view(oenv, opt2fn("-o", NFILE, fnm), "-nxy"); /* view xvgr file */