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56 int gmx_filter(int argc, char *argv[])
58 const char *desc[] = {
59 "[TT]g_filter[tt] performs frequency filtering on a trajectory.",
60 "The filter shape is cos([GRK]pi[grk] t/A) + 1 from -A to +A, where A is given",
61 "by the option [TT]-nf[tt] times the time step in the input trajectory.",
62 "This filter reduces fluctuations with period A by 85%, with period",
63 "2*A by 50% and with period 3*A by 17% for low-pass filtering.",
64 "Both a low-pass and high-pass filtered trajectory can be written.[PAR]",
66 "Option [TT]-ol[tt] writes a low-pass filtered trajectory.",
67 "A frame is written every [TT]-nf[tt] input frames.",
68 "This ratio of filter length and output interval ensures a good",
69 "suppression of aliasing of high-frequency motion, which is useful for",
70 "making smooth movies. Also averages of properties which are linear",
71 "in the coordinates are preserved, since all input frames are weighted",
72 "equally in the output.",
73 "When all frames are needed, use the [TT]-all[tt] option.[PAR]",
75 "Option [TT]-oh[tt] writes a high-pass filtered trajectory.",
76 "The high-pass filtered coordinates are added to the coordinates",
77 "from the structure file. When using high-pass filtering use [TT]-fit[tt]",
78 "or make sure you use a trajectory that has been fitted on",
79 "the coordinates in the structure file."
83 static gmx_bool bNoJump = TRUE, bFit = FALSE, bLowAll = FALSE;
85 { "-nf", FALSE, etINT, {&nf},
86 "Sets the filter length as well as the output interval for low-pass filtering" },
87 { "-all", FALSE, etBOOL, {&bLowAll},
88 "Write all low-pass filtered frames" },
89 { "-nojump", FALSE, etBOOL, {&bNoJump},
90 "Remove jumps of atoms across the box" },
91 { "-fit", FALSE, etBOOL, {&bFit},
92 "Fit all frames to a reference structure" }
94 const char *topfile, *lowfile, *highfile;
95 gmx_bool bTop = FALSE;
99 matrix topbox, *box, boxf;
100 char title[256], *grpname;
105 t_trxstatus *outl, *outh;
106 int nffr, i, fr, nat, j, d, m;
108 real flen, *filt, sum, *t;
109 rvec xcmtop, xcm, **x, *ptr, *xf, *xn, *xp, hbox;
111 gmx_rmpbc_t gpbc = NULL;
113 #define NLEG asize(leg)
115 { efTRX, "-f", NULL, ffREAD },
116 { efTPS, NULL, NULL, ffOPTRD },
117 { efNDX, NULL, NULL, ffOPTRD },
118 { efTRO, "-ol", "lowpass", ffOPTWR },
119 { efTRO, "-oh", "highpass", ffOPTWR }
121 #define NFILE asize(fnm)
123 parse_common_args(&argc, argv, PCA_CAN_TIME | PCA_CAN_VIEW | PCA_BE_NICE,
124 NFILE, fnm, asize(pa), pa, asize(desc), desc, 0, NULL, &oenv);
126 highfile = opt2fn_null("-oh", NFILE, fnm);
129 topfile = ftp2fn(efTPS, NFILE, fnm);
130 lowfile = opt2fn_null("-ol", NFILE, fnm);
134 topfile = ftp2fn_null(efTPS, NFILE, fnm);
135 lowfile = opt2fn("-ol", NFILE, fnm);
139 bTop = read_tps_conf(ftp2fn(efTPS, NFILE, fnm), title, &top, &ePBC,
140 &xtop, NULL, topbox, TRUE);
143 gpbc = gmx_rmpbc_init(&top.idef, ePBC, top.atoms.nr, topbox);
144 gmx_rmpbc(gpbc, top.atoms.nr, topbox, xtop);
151 fprintf(stderr, "Select group for least squares fit\n");
152 get_index(&top.atoms, ftp2fn_null(efNDX, NFILE, fnm), 1, &isize, &index, &grpname);
154 snew(w_rls, top.atoms.nr);
155 for (i = 0; i < isize; i++)
157 w_rls[index[i]] = top.atoms.atom[index[i]].m;
159 calc_xcm(xtop, isize, index, top.atoms.atom, xcmtop, FALSE);
160 for (j = 0; j < top.atoms.nr; j++)
162 rvec_dec(xtop[j], xcmtop);
166 /* The actual filter length flen can actually be any real number */
168 /* nffr is the number of frames that we filter over */
172 for (i = 0; i < nffr; i++)
174 filt[i] = cos(2*M_PI*(i - nf + 1)/(real)flen) + 1;
177 fprintf(stdout, "filter weights:");
178 for (i = 0; i < nffr; i++)
181 fprintf(stdout, " %5.3f", filt[i]);
183 fprintf(stdout, "\n");
189 nat = read_first_x(oenv, &in, opt2fn("-f", NFILE, fnm),
190 &(t[nffr - 1]), &(x[nffr - 1]), box[nffr - 1]);
192 for (i = 0; i < nat; i++)
196 /* x[nffr - 1] was already allocated by read_first_x */
197 for (i = 0; i < nffr-1; i++)
204 outl = open_trx(lowfile, "w");
212 outh = open_trx(highfile, "w");
223 if (bNoJump && fr > 0)
226 for (j = 0; j < nat; j++)
228 for (d = 0; d < DIM; d++)
230 hbox[d] = 0.5*box[nffr - 1][d][d];
233 for (i = 0; i < nat; i++)
235 for (m = DIM-1; m >= 0; m--)
239 while (xn[i][m] - xp[i][m] <= -hbox[m])
241 for (d = 0; d <= m; d++)
243 xn[i][d] += box[nffr - 1][m][d];
246 while (xn[i][m] - xp[i][m] > hbox[m])
248 for (d = 0; d <= m; d++)
250 xn[i][d] -= box[nffr - 1][m][d];
259 gmx_rmpbc(gpbc, nat, box[nffr - 1], xn);
263 calc_xcm(xn, isize, index, top.atoms.atom, xcm, FALSE);
264 for (j = 0; j < nat; j++)
266 rvec_dec(xn[j], xcm);
268 do_fit(nat, w_rls, xtop, xn);
269 for (j = 0; j < nat; j++)
271 rvec_inc(xn[j], xcmtop);
274 if (fr >= nffr && (outh || bLowAll || fr % nf == nf - 1))
276 /* Lowpass filtering */
277 for (j = 0; j < nat; j++)
282 for (i = 0; i < nffr; i++)
284 for (j = 0; j < nat; j++)
286 for (d = 0; d < DIM; d++)
288 xf[j][d] += filt[i]*x[i][j][d];
291 for (j = 0; j < DIM; j++)
293 for (d = 0; d < DIM; d++)
295 boxf[j][d] += filt[i]*box[i][j][d];
299 if (outl && (bLowAll || fr % nf == nf - 1))
301 write_trx(outl, nat, ind, topfile ? &(top.atoms) : NULL,
302 0, t[nf - 1], bFit ? topbox : boxf, xf, NULL, NULL);
306 /* Highpass filtering */
307 for (j = 0; j < nat; j++)
309 for (d = 0; d < DIM; d++)
311 xf[j][d] = xtop[j][d] + x[nf - 1][j][d] - xf[j][d];
316 for (j = 0; j < nat; j++)
318 rvec_inc(xf[j], xcmtop);
321 for (j = 0; j < DIM; j++)
323 for (d = 0; d < DIM; d++)
325 boxf[j][d] = topbox[j][d] + box[nf - 1][j][d] - boxf[j][d];
328 write_trx(outh, nat, ind, topfile ? &(top.atoms) : NULL,
329 0, t[nf - 1], bFit ? topbox : boxf, xf, NULL, NULL);
332 /* Cycle all the pointer and the box by one */
334 for (i = 0; i < nffr-1; i++)
338 copy_mat(box[i+1], box[i]);
343 while (read_next_x(oenv, in, &(t[nffr - 1]), nat, x[nffr - 1], box[nffr - 1]));
347 gmx_rmpbc_done(gpbc);