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41 #include "gromacs/commandline/pargs.h"
42 #include "gromacs/fileio/trxio.h"
43 #include "gromacs/fileio/xvgr.h"
44 #include "gromacs/gmxana/gmx_ana.h"
45 #include "gromacs/gmxana/gstat.h"
46 #include "gromacs/math/do_fit.h"
47 #include "gromacs/math/units.h"
48 #include "gromacs/math/utilities.h"
49 #include "gromacs/math/vec.h"
50 #include "gromacs/pbcutil/pbc.h"
51 #include "gromacs/pbcutil/rmpbc.h"
52 #include "gromacs/topology/index.h"
53 #include "gromacs/topology/topology.h"
54 #include "gromacs/utility/arraysize.h"
55 #include "gromacs/utility/fatalerror.h"
56 #include "gromacs/utility/futil.h"
57 #include "gromacs/utility/smalloc.h"
59 int gmx_helixorient(int argc, char* argv[])
61 const char* desc[] = {
62 "[THISMODULE] calculates the coordinates and direction of the average",
63 "axis inside an alpha helix, and the direction/vectors of both the",
64 "C[GRK]alpha[grk] and (optionally) a sidechain atom relative to the axis.[PAR]",
65 "As input, you need to specify an index group with C[GRK]alpha[grk] atoms",
66 "corresponding to an [GRK]alpha[grk]-helix of continuous residues. Sidechain",
67 "directions require a second index group of the same size, containing",
68 "the heavy atom in each residue that should represent the sidechain.[PAR]",
69 "[BB]Note[bb] that this program does not do any fitting of structures.[PAR]",
70 "We need four C[GRK]alpha[grk] coordinates to define the local direction of the helix",
72 "The tilt/rotation is calculated from Euler rotations, where we define",
73 "the helix axis as the local [IT]x[it]-axis, the residues/C[GRK]alpha[grk] vector as ",
75 "[IT]z[it]-axis from their cross product. We use the Euler Y-Z-X rotation, meaning",
76 "we first tilt the helix axis (1) around and (2) orthogonal to the residues",
77 "vector, and finally apply the (3) rotation around it. For debugging or other",
78 "purposes, we also write out the actual Euler rotation angles as [TT]theta[1-3].xvg[tt]"
81 t_topology* top = nullptr;
87 real theta1, theta2, theta3;
103 rvec* residuehelixaxis;
106 rvec* sidechainvector;
108 rvec* residuehelixaxis_t0;
109 rvec* residuevector_t0;
111 rvec* residuehelixaxis_tlast;
112 rvec* residuevector_tlast;
114 rvec refaxes[3], newaxes[3];
116 rvec rot_refaxes[3], rot_newaxes[3];
120 real *twist, *residuetwist;
121 real *radius, *residueradius;
122 real *rise, *residuerise;
123 real* residuebending;
130 FILE * fpaxis, *fpcenter, *fptilt, *fprotation;
131 FILE * fpradius, *fprise, *fptwist;
132 FILE * fptheta1, *fptheta2, *fptheta3;
136 gmx_output_env_t* oenv;
137 gmx_rmpbc_t gpbc = nullptr;
139 static gmx_bool bSC = FALSE;
140 static gmx_bool bIncremental = FALSE;
142 static t_pargs pa[] = {
147 "Calculate sidechain directions relative to helix axis too." },
152 "Calculate incremental rather than total rotation/tilt." },
154 #define NPA asize(pa)
157 { efTPR, nullptr, nullptr, ffREAD }, { efTRX, "-f", nullptr, ffREAD },
158 { efNDX, nullptr, nullptr, ffOPTRD }, { efDAT, "-oaxis", "helixaxis", ffWRITE },
159 { efDAT, "-ocenter", "center", ffWRITE }, { efXVG, "-orise", "rise", ffWRITE },
160 { efXVG, "-oradius", "radius", ffWRITE }, { efXVG, "-otwist", "twist", ffWRITE },
161 { efXVG, "-obending", "bending", ffWRITE }, { efXVG, "-otilt", "tilt", ffWRITE },
162 { efXVG, "-orot", "rotation", ffWRITE }
164 #define NFILE asize(fnm)
166 if (!parse_common_args(
167 &argc, argv, PCA_CAN_TIME, NFILE, fnm, NPA, pa, asize(desc), desc, 0, nullptr, &oenv))
172 top = read_top(ftp2fn(efTPR, NFILE, fnm), &pbcType);
174 for (i = 0; i < 3; i++)
179 /* read index files */
180 printf("Select a group of Calpha atoms corresponding to a single continuous helix:\n");
181 get_index(&(top->atoms), ftp2fn_null(efNDX, NFILE, fnm), 1, &iCA, &ind_CA, &gn_CA);
183 snew(x_SC, iCA); /* sic! */
188 snew(diff13, iCA - 3);
189 snew(diff24, iCA - 3);
190 snew(helixaxis, iCA - 3);
192 snew(residuetwist, iCA);
194 snew(residueradius, iCA);
196 snew(residuerise, iCA);
197 snew(residueorigin, iCA);
198 snew(residuehelixaxis, iCA);
199 snew(residuevector, iCA);
200 snew(sidechainvector, iCA);
201 snew(residuebending, iCA);
202 snew(residuehelixaxis_t0, iCA);
203 snew(residuevector_t0, iCA);
205 snew(residuehelixaxis_tlast, iCA);
206 snew(residuevector_tlast, iCA);
207 snew(axis3_tlast, iCA);
212 printf("Select a group of atoms defining the sidechain direction (1/residue):\n");
213 get_index(&(top->atoms), ftp2fn_null(efNDX, NFILE, fnm), 1, &iSC, &ind_SC, &gn_SC);
216 gmx_fatal(FARGS, "Number of sidechain atoms (%d) != number of CA atoms (%d)", iSC, iCA);
220 natoms = read_first_x(oenv, &status, ftp2fn(efTRX, NFILE, fnm), &t, &x, box);
222 fpaxis = gmx_ffopen(opt2fn("-oaxis", NFILE, fnm), "w");
223 fpcenter = gmx_ffopen(opt2fn("-ocenter", NFILE, fnm), "w");
224 fprise = gmx_ffopen(opt2fn("-orise", NFILE, fnm), "w");
225 fpradius = gmx_ffopen(opt2fn("-oradius", NFILE, fnm), "w");
226 fptwist = gmx_ffopen(opt2fn("-otwist", NFILE, fnm), "w");
227 fpbending = gmx_ffopen(opt2fn("-obending", NFILE, fnm), "w");
229 fptheta1 = gmx_ffopen("theta1.xvg", "w");
230 fptheta2 = gmx_ffopen("theta2.xvg", "w");
231 fptheta3 = gmx_ffopen("theta3.xvg", "w");
235 fptilt = xvgropen(opt2fn("-otilt", NFILE, fnm),
236 "Incremental local helix tilt",
240 fprotation = xvgropen(opt2fn("-orot", NFILE, fnm),
241 "Incremental local helix rotation",
243 "Rotation (degrees)",
248 fptilt = xvgropen(opt2fn("-otilt", NFILE, fnm),
249 "Cumulative local helix tilt",
253 fprotation = xvgropen(opt2fn("-orot", NFILE, fnm),
254 "Cumulative local helix rotation",
256 "Rotation (degrees)",
260 clear_rvecs(3, unitaxes);
265 gpbc = gmx_rmpbc_init(&top->idef, pbcType, natoms);
269 /* initialisation for correct distance calculations */
270 set_pbc(&pbc, pbcType, box);
271 /* make molecules whole again */
272 gmx_rmpbc(gpbc, natoms, box, x);
274 /* copy coords to our smaller arrays */
275 for (i = 0; i < iCA; i++)
277 copy_rvec(x[ind_CA[i]], x_CA[i]);
280 copy_rvec(x[ind_SC[i]], x_SC[i]);
284 for (i = 0; i < iCA - 3; i++)
286 rvec_sub(x_CA[i + 1], x_CA[i], r12[i]);
287 rvec_sub(x_CA[i + 2], x_CA[i + 1], r23[i]);
288 rvec_sub(x_CA[i + 3], x_CA[i + 2], r34[i]);
289 rvec_sub(r12[i], r23[i], diff13[i]);
290 rvec_sub(r23[i], r34[i], diff24[i]);
291 /* calculate helix axis */
292 cprod(diff13[i], diff24[i], helixaxis[i]);
293 svmul(1.0 / norm(helixaxis[i]), helixaxis[i], helixaxis[i]);
295 tmp = cos_angle(diff13[i], diff24[i]);
296 twist[i] = 180.0 / M_PI * std::acos(tmp);
297 radius[i] = std::sqrt(norm(diff13[i]) * norm(diff24[i])) / (2.0 * (1.0 - tmp));
298 rise[i] = std::abs(iprod(r23[i], helixaxis[i]));
300 svmul(radius[i] / norm(diff13[i]), diff13[i], v1);
301 svmul(radius[i] / norm(diff24[i]), diff24[i], v2);
303 rvec_sub(x_CA[i + 1], v1, residueorigin[i + 1]);
304 rvec_sub(x_CA[i + 2], v2, residueorigin[i + 2]);
306 residueradius[0] = residuetwist[0] = residuerise[0] = 0;
308 residueradius[1] = radius[0];
309 residuetwist[1] = twist[0];
310 residuerise[1] = rise[0];
312 residuebending[0] = residuebending[1] = 0;
313 for (i = 2; i < iCA - 2; i++)
315 residueradius[i] = 0.5 * (radius[i - 2] + radius[i - 1]);
316 residuetwist[i] = 0.5 * (twist[i - 2] + twist[i - 1]);
317 residuerise[i] = 0.5 * (rise[i - 2] + rise[i - 1]);
318 residuebending[i] = 180.0 / M_PI * std::acos(cos_angle(helixaxis[i - 2], helixaxis[i - 1]));
320 residueradius[iCA - 2] = radius[iCA - 4];
321 residuetwist[iCA - 2] = twist[iCA - 4];
322 residuerise[iCA - 2] = rise[iCA - 4];
323 residueradius[iCA - 1] = residuetwist[iCA - 1] = residuerise[iCA - 1] = 0;
324 residuebending[iCA - 2] = residuebending[iCA - 1] = 0;
326 clear_rvec(residueorigin[0]);
327 clear_rvec(residueorigin[iCA - 1]);
329 /* average helix axes to define them on the residues.
330 * Just extrapolate second first/list atom.
332 copy_rvec(helixaxis[0], residuehelixaxis[0]);
333 copy_rvec(helixaxis[0], residuehelixaxis[1]);
335 for (i = 2; i < iCA - 2; i++)
337 rvec_add(helixaxis[i - 2], helixaxis[i - 1], residuehelixaxis[i]);
338 svmul(0.5, residuehelixaxis[i], residuehelixaxis[i]);
340 copy_rvec(helixaxis[iCA - 4], residuehelixaxis[iCA - 2]);
341 copy_rvec(helixaxis[iCA - 4], residuehelixaxis[iCA - 1]);
343 /* Normalize the axis */
344 for (i = 0; i < iCA; i++)
346 svmul(1.0 / norm(residuehelixaxis[i]), residuehelixaxis[i], residuehelixaxis[i]);
349 /* calculate vector from origin to residue CA */
350 fprintf(fpaxis, "%15.12g ", t);
351 fprintf(fpcenter, "%15.12g ", t);
352 fprintf(fprise, "%15.12g ", t);
353 fprintf(fpradius, "%15.12g ", t);
354 fprintf(fptwist, "%15.12g ", t);
355 fprintf(fpbending, "%15.12g ", t);
357 for (i = 0; i < iCA; i++)
359 if (i == 0 || i == iCA - 1)
361 fprintf(fpaxis, "%15.12g %15.12g %15.12g ", 0.0, 0.0, 0.0);
362 fprintf(fpcenter, "%15.12g %15.12g %15.12g ", 0.0, 0.0, 0.0);
363 fprintf(fprise, "%15.12g ", 0.0);
364 fprintf(fpradius, "%15.12g ", 0.0);
365 fprintf(fptwist, "%15.12g ", 0.0);
366 fprintf(fpbending, "%15.12g ", 0.0);
370 rvec_sub(bSC ? x_SC[i] : x_CA[i], residueorigin[i], residuevector[i]);
371 svmul(1.0 / norm(residuevector[i]), residuevector[i], residuevector[i]);
372 cprod(residuehelixaxis[i], residuevector[i], axis3[i]);
374 "%15.12g %15.12g %15.12g ",
375 residuehelixaxis[i][0],
376 residuehelixaxis[i][1],
377 residuehelixaxis[i][2]);
379 "%15.12g %15.12g %15.12g ",
382 residueorigin[i][2]);
384 fprintf(fprise, "%15.12g ", residuerise[i]);
385 fprintf(fpradius, "%15.12g ", residueradius[i]);
386 fprintf(fptwist, "%15.12g ", residuetwist[i]);
387 fprintf(fpbending, "%15.12g ", residuebending[i]);
390 fprintf(fprise, "\n");
391 fprintf(fpradius, "\n");
392 fprintf(fpaxis, "\n");
393 fprintf(fpcenter, "\n");
394 fprintf(fptwist, "\n");
395 fprintf(fpbending, "\n");
399 for (i = 0; i < iCA; i++)
401 copy_rvec(residuehelixaxis[i], residuehelixaxis_t0[i]);
402 copy_rvec(residuevector[i], residuevector_t0[i]);
403 copy_rvec(axis3[i], axis3_t0[i]);
408 fprintf(fptilt, "%15.12g ", t);
409 fprintf(fprotation, "%15.12g ", t);
410 fprintf(fptheta1, "%15.12g ", t);
411 fprintf(fptheta2, "%15.12g ", t);
412 fprintf(fptheta3, "%15.12g ", t);
414 for (i = 0; i < iCA; i++)
416 if (i == 0 || i == iCA - 1)
424 /* Total rotation & tilt */
425 copy_rvec(residuehelixaxis_t0[i], refaxes[0]);
426 copy_rvec(residuevector_t0[i], refaxes[1]);
427 copy_rvec(axis3_t0[i], refaxes[2]);
431 /* Rotation/tilt since last step */
432 copy_rvec(residuehelixaxis_tlast[i], refaxes[0]);
433 copy_rvec(residuevector_tlast[i], refaxes[1]);
434 copy_rvec(axis3_tlast[i], refaxes[2]);
436 copy_rvec(residuehelixaxis[i], newaxes[0]);
437 copy_rvec(residuevector[i], newaxes[1]);
438 copy_rvec(axis3[i], newaxes[2]);
440 /* rotate reference frame onto unit axes */
441 calc_fit_R(3, 3, weight, unitaxes, refaxes, A);
442 for (j = 0; j < 3; j++)
444 mvmul(A, refaxes[j], rot_refaxes[j]);
445 mvmul(A, newaxes[j], rot_newaxes[j]);
448 /* Determine local rotation matrix A */
449 calc_fit_R(3, 3, weight, rot_newaxes, rot_refaxes, A);
450 /* Calculate euler angles, from rotation order y-z-x, where
451 * x is helixaxis, y residuevector, and z axis3.
453 * A contains rotation column vectors.
456 theta1 = 180.0 / M_PI * std::atan2(A[0][2], A[0][0]);
457 theta2 = 180.0 / M_PI * std::asin(-A[0][1]);
458 theta3 = 180.0 / M_PI * std::atan2(A[2][1], A[1][1]);
460 tilt = std::sqrt(theta1 * theta1 + theta2 * theta2);
462 fprintf(fptheta1, "%15.12g ", theta1);
463 fprintf(fptheta2, "%15.12g ", theta2);
464 fprintf(fptheta3, "%15.12g ", theta3);
466 fprintf(fptilt, "%15.12g ", tilt);
467 fprintf(fprotation, "%15.12g ", rotation);
469 fprintf(fptilt, "\n");
470 fprintf(fprotation, "\n");
471 fprintf(fptheta1, "\n");
472 fprintf(fptheta2, "\n");
473 fprintf(fptheta3, "\n");
476 for (i = 0; i < iCA; i++)
478 copy_rvec(residuehelixaxis[i], residuehelixaxis_tlast[i]);
479 copy_rvec(residuevector[i], residuevector_tlast[i]);
480 copy_rvec(axis3[i], axis3_tlast[i]);
484 } while (read_next_x(oenv, status, &t, x, box));
486 gmx_rmpbc_done(gpbc);
489 gmx_ffclose(fpcenter);
491 xvgrclose(fprotation);
493 gmx_ffclose(fpradius);
494 gmx_ffclose(fptwist);
495 gmx_ffclose(fpbending);
496 gmx_ffclose(fptheta1);
497 gmx_ffclose(fptheta2);
498 gmx_ffclose(fptheta3);