Files
lammps/lib/colvars/colvarcomp_distances.cpp
Giacomo Fiorin 1220bea011 Update Colvars to version 2022-05-09
This update includes one new feature (neural-network based collective
variables), several small enhancements (including an automatic definition of
grid boundaries for angle-based CVs, and a normalization option for
eigenvector-based CVs), bugfixes and documentation improvements.

Usage information for specific features included in the Colvars library
(i.e. not just the library as a whole) is now also reported to the screen or
LAMMPS logfile (as is done already in other LAMMPS classes).

Notable to LAMMPS code development are the removals of duplicated code and of
ambiguously-named preprocessor defines in the Colvars headers.  Since the
last PR, the existing regression tests have also been running automatically
via GitHub Actions.

The following pull requests in the Colvars repository are relevant to LAMMPS:

- 475 Remove fatal error condition
  https://github.com/Colvars/colvars/pull/475 (@jhenin, @giacomofiorin)

- 474 Allow normalizing eigenvector vector components to deal with unit change
  https://github.com/Colvars/colvars/pull/474 (@giacomofiorin, @jhenin)

- 470 Better error handling in the initialization of NeuralNetwork CV
  https://github.com/Colvars/colvars/pull/470 (@HanatoK)

- 468 Add examples of histogram configuration, with and without explicit grid parameters
  https://github.com/Colvars/colvars/pull/468 (@giacomofiorin)

- 464 Fix #463 using more fine-grained features
  https://github.com/Colvars/colvars/pull/464 (@jhenin, @giacomofiorin)

- 447 [RFC] New option "scaledBiasingForce" for colvarbias
  https://github.com/Colvars/colvars/pull/447 (@HanatoK, @jhenin)

- 444 [RFC] Implementation of dense neural network as CV
  https://github.com/Colvars/colvars/pull/444 (@HanatoK, @giacomofiorin, @jhenin)

- 443 Fix explicit gradient dependency of sub-CVs
  https://github.com/Colvars/colvars/pull/443 (@HanatoK, @jhenin)

- 442 Persistent bias count
  https://github.com/Colvars/colvars/pull/442 (@jhenin, @giacomofiorin)

- 437 Return type of bias from scripting interface
  https://github.com/Colvars/colvars/pull/437 (@giacomofiorin)

- 434 More flexible use of boundaries from colvars by grids
  https://github.com/Colvars/colvars/pull/434 (@jhenin)

- 433 Prevent double-free in linearCombination
  https://github.com/Colvars/colvars/pull/433 (@HanatoK)

- 428 More complete documentation for index file format (NDX)
  https://github.com/Colvars/colvars/pull/428 (@giacomofiorin)

- 426 Integrate functional version of backup_file() into base proxy class
  https://github.com/Colvars/colvars/pull/426 (@giacomofiorin)

- 424 Track CVC inheritance when documenting feature usage
  https://github.com/Colvars/colvars/pull/424 (@giacomofiorin)

- 419 Generate citation report while running computations
  https://github.com/Colvars/colvars/pull/419 (@giacomofiorin, @jhenin)

- 415 Rebin metadynamics bias from explicit hills when available
  https://github.com/Colvars/colvars/pull/415 (@giacomofiorin)

- 312 Ignore a keyword if it has content to the left of it (regardless of braces)
  https://github.com/Colvars/colvars/pull/312 (@giacomofiorin)

Authors: @giacomofiorin, @HanatoK, @jhenin
2022-05-10 11:24:54 -04:00

1575 lines
44 KiB
C++

// -*- c++ -*-
// This file is part of the Collective Variables module (Colvars).
// The original version of Colvars and its updates are located at:
// https://github.com/Colvars/colvars
// Please update all Colvars source files before making any changes.
// If you wish to distribute your changes, please submit them to the
// Colvars repository at GitHub.
#include <algorithm>
#include "colvarmodule.h"
#include "colvarvalue.h"
#include "colvarparse.h"
#include "colvar.h"
#include "colvarcomp.h"
colvar::distance::distance(std::string const &conf)
: cvc(conf)
{
set_function_type("distance");
init_as_distance();
provide(f_cvc_inv_gradient);
provide(f_cvc_Jacobian);
enable(f_cvc_com_based);
group1 = parse_group(conf, "group1");
group2 = parse_group(conf, "group2");
init_total_force_params(conf);
}
colvar::distance::distance()
: cvc()
{
set_function_type("distance");
init_as_distance();
provide(f_cvc_inv_gradient);
provide(f_cvc_Jacobian);
enable(f_cvc_com_based);
}
void colvar::distance::calc_value()
{
if (!is_enabled(f_cvc_pbc_minimum_image)) {
dist_v = group2->center_of_mass() - group1->center_of_mass();
} else {
dist_v = cvm::position_distance(group1->center_of_mass(),
group2->center_of_mass());
}
x.real_value = dist_v.norm();
}
void colvar::distance::calc_gradients()
{
cvm::rvector const u = dist_v.unit();
group1->set_weighted_gradient(-1.0 * u);
group2->set_weighted_gradient( u);
}
void colvar::distance::calc_force_invgrads()
{
group1->read_total_forces();
if (is_enabled(f_cvc_one_site_total_force)) {
ft.real_value = -1.0 * (group1->total_force() * dist_v.unit());
} else {
group2->read_total_forces();
ft.real_value = 0.5 * ((group2->total_force() - group1->total_force()) * dist_v.unit());
}
}
void colvar::distance::calc_Jacobian_derivative()
{
jd.real_value = x.real_value ? (2.0 / x.real_value) : 0.0;
}
void colvar::distance::apply_force(colvarvalue const &force)
{
if (!group1->noforce)
group1->apply_colvar_force(force.real_value);
if (!group2->noforce)
group2->apply_colvar_force(force.real_value);
}
simple_scalar_dist_functions(distance)
colvar::distance_vec::distance_vec(std::string const &conf)
: distance(conf)
{
set_function_type("distanceVec");
enable(f_cvc_com_based);
disable(f_cvc_explicit_gradient);
x.type(colvarvalue::type_3vector);
}
colvar::distance_vec::distance_vec()
: distance()
{
set_function_type("distanceVec");
enable(f_cvc_com_based);
disable(f_cvc_explicit_gradient);
x.type(colvarvalue::type_3vector);
}
void colvar::distance_vec::calc_value()
{
if (!is_enabled(f_cvc_pbc_minimum_image)) {
x.rvector_value = group2->center_of_mass() - group1->center_of_mass();
} else {
x.rvector_value = cvm::position_distance(group1->center_of_mass(),
group2->center_of_mass());
}
}
void colvar::distance_vec::calc_gradients()
{
// gradients are not stored: a 3x3 matrix for each atom would be
// needed to store just the identity matrix
}
void colvar::distance_vec::apply_force(colvarvalue const &force)
{
if (!group1->noforce)
group1->apply_force(-1.0 * force.rvector_value);
if (!group2->noforce)
group2->apply_force( force.rvector_value);
}
cvm::real colvar::distance_vec::dist2(colvarvalue const &x1,
colvarvalue const &x2) const
{
return (cvm::position_distance(x1.rvector_value, x2.rvector_value)).norm2();
}
colvarvalue colvar::distance_vec::dist2_lgrad(colvarvalue const &x1,
colvarvalue const &x2) const
{
return 2.0 * cvm::position_distance(x2.rvector_value, x1.rvector_value);
}
colvarvalue colvar::distance_vec::dist2_rgrad(colvarvalue const &x1,
colvarvalue const &x2) const
{
return 2.0 * cvm::position_distance(x2.rvector_value, x1.rvector_value);
}
colvar::distance_z::distance_z(std::string const &conf)
: cvc(conf)
{
set_function_type("distanceZ");
provide(f_cvc_inv_gradient);
provide(f_cvc_Jacobian);
enable(f_cvc_com_based);
x.type(colvarvalue::type_scalar);
// TODO detect PBC from MD engine (in simple cases)
// and then update period in real time
if (period != 0.0) {
enable(f_cvc_periodic);
}
if ((wrap_center != 0.0) && !is_enabled(f_cvc_periodic)) {
cvm::error("Error: wrapAround was defined in a distanceZ component,"
" but its period has not been set.\n");
return;
}
main = parse_group(conf, "main");
ref1 = parse_group(conf, "ref");
// this group is optional
ref2 = parse_group(conf, "ref2", true);
if ( ref2 ) {
cvm::log("Using axis joining the centers of mass of groups \"ref\" and \"ref2\"\n");
fixed_axis = false;
if (key_lookup(conf, "axis"))
cvm::log("Warning: explicit axis definition will be ignored!\n");
} else {
if (get_keyval(conf, "axis", axis, cvm::rvector(0.0, 0.0, 1.0))) {
if (axis.norm2() == 0.0) {
cvm::error("Axis vector is zero!");
return;
}
if (axis.norm2() != 1.0) {
axis = axis.unit();
cvm::log("The normalized axis is: "+cvm::to_str(axis)+".\n");
}
}
fixed_axis = true;
}
init_total_force_params(conf);
}
colvar::distance_z::distance_z()
{
set_function_type("distanceZ");
provide(f_cvc_inv_gradient);
provide(f_cvc_Jacobian);
enable(f_cvc_com_based);
x.type(colvarvalue::type_scalar);
}
void colvar::distance_z::calc_value()
{
if (fixed_axis) {
if (!is_enabled(f_cvc_pbc_minimum_image)) {
dist_v = main->center_of_mass() - ref1->center_of_mass();
} else {
dist_v = cvm::position_distance(ref1->center_of_mass(),
main->center_of_mass());
}
} else {
if (!is_enabled(f_cvc_pbc_minimum_image)) {
dist_v = main->center_of_mass() -
(0.5 * (ref1->center_of_mass() + ref2->center_of_mass()));
axis = ref2->center_of_mass() - ref1->center_of_mass();
} else {
dist_v = cvm::position_distance(0.5 * (ref1->center_of_mass() +
ref2->center_of_mass()),
main->center_of_mass());
axis = cvm::position_distance(ref1->center_of_mass(),
ref2->center_of_mass());
}
axis_norm = axis.norm();
axis = axis.unit();
}
x.real_value = axis * dist_v;
this->wrap(x);
}
void colvar::distance_z::calc_gradients()
{
main->set_weighted_gradient( axis );
if (fixed_axis) {
ref1->set_weighted_gradient(-1.0 * axis);
} else {
if (!is_enabled(f_cvc_pbc_minimum_image)) {
ref1->set_weighted_gradient( 1.0 / axis_norm *
(main->center_of_mass() - ref2->center_of_mass() -
x.real_value * axis ));
ref2->set_weighted_gradient( 1.0 / axis_norm *
(ref1->center_of_mass() - main->center_of_mass() +
x.real_value * axis ));
} else {
ref1->set_weighted_gradient( 1.0 / axis_norm * (
cvm::position_distance(ref2->center_of_mass(),
main->center_of_mass()) - x.real_value * axis ));
ref2->set_weighted_gradient( 1.0 / axis_norm * (
cvm::position_distance(main->center_of_mass(),
ref1->center_of_mass()) + x.real_value * axis ));
}
}
}
void colvar::distance_z::calc_force_invgrads()
{
main->read_total_forces();
if (fixed_axis && !is_enabled(f_cvc_one_site_total_force)) {
ref1->read_total_forces();
ft.real_value = 0.5 * ((main->total_force() - ref1->total_force()) * axis);
} else {
ft.real_value = main->total_force() * axis;
}
}
void colvar::distance_z::calc_Jacobian_derivative()
{
jd.real_value = 0.0;
}
void colvar::distance_z::apply_force(colvarvalue const &force)
{
if (!ref1->noforce)
ref1->apply_colvar_force(force.real_value);
if (ref2 && !ref2->noforce)
ref2->apply_colvar_force(force.real_value);
if (!main->noforce)
main->apply_colvar_force(force.real_value);
}
// Differences should always be wrapped around 0 (ignoring wrap_center)
cvm::real colvar::distance_z::dist2(colvarvalue const &x1,
colvarvalue const &x2) const
{
cvm::real diff = x1.real_value - x2.real_value;
if (is_enabled(f_cvc_periodic)) {
cvm::real shift = cvm::floor(diff/period + 0.5);
diff -= shift * period;
}
return diff * diff;
}
colvarvalue colvar::distance_z::dist2_lgrad(colvarvalue const &x1,
colvarvalue const &x2) const
{
cvm::real diff = x1.real_value - x2.real_value;
if (is_enabled(f_cvc_periodic)) {
cvm::real shift = cvm::floor(diff/period + 0.5);
diff -= shift * period;
}
return 2.0 * diff;
}
colvarvalue colvar::distance_z::dist2_rgrad(colvarvalue const &x1,
colvarvalue const &x2) const
{
cvm::real diff = x1.real_value - x2.real_value;
if (is_enabled(f_cvc_periodic)) {
cvm::real shift = cvm::floor(diff/period + 0.5);
diff -= shift * period;
}
return (-2.0) * diff;
}
void colvar::distance_z::wrap(colvarvalue &x_unwrapped) const
{
if (!is_enabled(f_cvc_periodic)) {
// don't wrap if the period has not been set
return;
}
cvm::real shift =
cvm::floor((x_unwrapped.real_value - wrap_center) / period + 0.5);
x_unwrapped.real_value -= shift * period;
}
colvar::distance_xy::distance_xy(std::string const &conf)
: distance_z(conf)
{
set_function_type("distanceXY");
init_as_distance();
provide(f_cvc_inv_gradient);
provide(f_cvc_Jacobian);
enable(f_cvc_com_based);
}
colvar::distance_xy::distance_xy()
: distance_z()
{
set_function_type("distanceXY");
init_as_distance();
provide(f_cvc_inv_gradient);
provide(f_cvc_Jacobian);
enable(f_cvc_com_based);
}
void colvar::distance_xy::calc_value()
{
if (!is_enabled(f_cvc_pbc_minimum_image)) {
dist_v = main->center_of_mass() - ref1->center_of_mass();
} else {
dist_v = cvm::position_distance(ref1->center_of_mass(),
main->center_of_mass());
}
if (!fixed_axis) {
if (!is_enabled(f_cvc_pbc_minimum_image)) {
v12 = ref2->center_of_mass() - ref1->center_of_mass();
} else {
v12 = cvm::position_distance(ref1->center_of_mass(),
ref2->center_of_mass());
}
axis_norm = v12.norm();
axis = v12.unit();
}
dist_v_ortho = dist_v - (dist_v * axis) * axis;
x.real_value = dist_v_ortho.norm();
}
void colvar::distance_xy::calc_gradients()
{
// Intermediate quantity (r_P3 / r_12 where P is the projection
// of 3(main) on the plane orthogonal to 12, containing 1 (ref1))
cvm::real A;
cvm::real x_inv;
if (x.real_value == 0.0) return;
x_inv = 1.0 / x.real_value;
if (fixed_axis) {
ref1->set_weighted_gradient(-1.0 * x_inv * dist_v_ortho);
main->set_weighted_gradient( x_inv * dist_v_ortho);
} else {
if (!is_enabled(f_cvc_pbc_minimum_image)) {
v13 = main->center_of_mass() - ref1->center_of_mass();
} else {
v13 = cvm::position_distance(ref1->center_of_mass(),
main->center_of_mass());
}
A = (dist_v * axis) / axis_norm;
ref1->set_weighted_gradient( (A - 1.0) * x_inv * dist_v_ortho);
ref2->set_weighted_gradient( -A * x_inv * dist_v_ortho);
main->set_weighted_gradient( 1.0 * x_inv * dist_v_ortho);
}
}
void colvar::distance_xy::calc_force_invgrads()
{
main->read_total_forces();
if (fixed_axis && !is_enabled(f_cvc_one_site_total_force)) {
ref1->read_total_forces();
ft.real_value = 0.5 / x.real_value * ((main->total_force() - ref1->total_force()) * dist_v_ortho);
} else {
ft.real_value = 1.0 / x.real_value * main->total_force() * dist_v_ortho;
}
}
void colvar::distance_xy::calc_Jacobian_derivative()
{
jd.real_value = x.real_value ? (1.0 / x.real_value) : 0.0;
}
void colvar::distance_xy::apply_force(colvarvalue const &force)
{
if (!ref1->noforce)
ref1->apply_colvar_force(force.real_value);
if (ref2 && !ref2->noforce)
ref2->apply_colvar_force(force.real_value);
if (!main->noforce)
main->apply_colvar_force(force.real_value);
}
simple_scalar_dist_functions(distance_xy)
colvar::distance_dir::distance_dir(std::string const &conf)
: distance(conf)
{
set_function_type("distanceDir");
enable(f_cvc_com_based);
disable(f_cvc_explicit_gradient);
x.type(colvarvalue::type_unit3vector);
}
colvar::distance_dir::distance_dir()
: distance()
{
set_function_type("distanceDir");
enable(f_cvc_com_based);
disable(f_cvc_explicit_gradient);
x.type(colvarvalue::type_unit3vector);
}
void colvar::distance_dir::calc_value()
{
if (!is_enabled(f_cvc_pbc_minimum_image)) {
dist_v = group2->center_of_mass() - group1->center_of_mass();
} else {
dist_v = cvm::position_distance(group1->center_of_mass(),
group2->center_of_mass());
}
x.rvector_value = dist_v.unit();
}
void colvar::distance_dir::calc_gradients()
{
// gradients are computed on the fly within apply_force()
// Note: could be a problem if a future bias relies on gradient
// calculations...
// TODO in new deps system: remove dependency of biasing force to gradient?
// That way we could tell apart an explicit gradient dependency
}
void colvar::distance_dir::apply_force(colvarvalue const &force)
{
// remove the radial force component
cvm::real const iprod = force.rvector_value * x.rvector_value;
cvm::rvector const force_tang = force.rvector_value - iprod * x.rvector_value;
if (!group1->noforce)
group1->apply_force(-1.0 * force_tang);
if (!group2->noforce)
group2->apply_force( force_tang);
}
cvm::real colvar::distance_dir::dist2(colvarvalue const &x1,
colvarvalue const &x2) const
{
return (x1.rvector_value - x2.rvector_value).norm2();
}
colvarvalue colvar::distance_dir::dist2_lgrad(colvarvalue const &x1,
colvarvalue const &x2) const
{
return colvarvalue((x1.rvector_value - x2.rvector_value), colvarvalue::type_unit3vectorderiv);
}
colvarvalue colvar::distance_dir::dist2_rgrad(colvarvalue const &x1,
colvarvalue const &x2) const
{
return colvarvalue((x2.rvector_value - x1.rvector_value), colvarvalue::type_unit3vectorderiv);
}
colvar::distance_inv::distance_inv(std::string const &conf)
: cvc(conf)
{
set_function_type("distanceInv");
init_as_distance();
group1 = parse_group(conf, "group1");
group2 = parse_group(conf, "group2");
get_keyval(conf, "exponent", exponent, 6);
if (exponent%2) {
cvm::error("Error: odd exponent provided, can only use even ones.\n");
return;
}
if (exponent <= 0) {
cvm::error("Error: negative or zero exponent provided.\n");
return;
}
for (cvm::atom_iter ai1 = group1->begin(); ai1 != group1->end(); ai1++) {
for (cvm::atom_iter ai2 = group2->begin(); ai2 != group2->end(); ai2++) {
if (ai1->id == ai2->id) {
cvm::error("Error: group1 and group2 have some atoms in common: this is not allowed for distanceInv.\n");
return;
}
}
}
if (is_enabled(f_cvc_debug_gradient)) {
cvm::log("Warning: debugGradients will not give correct results "
"for distanceInv, because its value and gradients are computed "
"simultaneously.\n");
}
}
void colvar::distance_inv::calc_value()
{
x.real_value = 0.0;
if (!is_enabled(f_cvc_pbc_minimum_image)) {
for (cvm::atom_iter ai1 = group1->begin(); ai1 != group1->end(); ai1++) {
for (cvm::atom_iter ai2 = group2->begin(); ai2 != group2->end(); ai2++) {
cvm::rvector const dv = ai2->pos - ai1->pos;
cvm::real const d2 = dv.norm2();
cvm::real const dinv = cvm::integer_power(d2, -1*(exponent/2));
x.real_value += dinv;
cvm::rvector const dsumddv = -1.0*(exponent/2) * dinv/d2 * 2.0 * dv;
ai1->grad += -1.0 * dsumddv;
ai2->grad += dsumddv;
}
}
} else {
for (cvm::atom_iter ai1 = group1->begin(); ai1 != group1->end(); ai1++) {
for (cvm::atom_iter ai2 = group2->begin(); ai2 != group2->end(); ai2++) {
cvm::rvector const dv = cvm::position_distance(ai1->pos, ai2->pos);
cvm::real const d2 = dv.norm2();
cvm::real const dinv = cvm::integer_power(d2, -1*(exponent/2));
x.real_value += dinv;
cvm::rvector const dsumddv = -1.0*(exponent/2) * dinv/d2 * 2.0 * dv;
ai1->grad += -1.0 * dsumddv;
ai2->grad += dsumddv;
}
}
}
x.real_value *= 1.0 / cvm::real(group1->size() * group2->size());
x.real_value = cvm::pow(x.real_value, -1.0/cvm::real(exponent));
cvm::real const dxdsum = (-1.0/(cvm::real(exponent))) *
cvm::integer_power(x.real_value, exponent+1) /
cvm::real(group1->size() * group2->size());
for (cvm::atom_iter ai1 = group1->begin(); ai1 != group1->end(); ai1++) {
ai1->grad *= dxdsum;
}
for (cvm::atom_iter ai2 = group2->begin(); ai2 != group2->end(); ai2++) {
ai2->grad *= dxdsum;
}
}
void colvar::distance_inv::calc_gradients()
{
}
void colvar::distance_inv::apply_force(colvarvalue const &force)
{
if (!group1->noforce)
group1->apply_colvar_force(force.real_value);
if (!group2->noforce)
group2->apply_colvar_force(force.real_value);
}
simple_scalar_dist_functions(distance_inv)
colvar::distance_pairs::distance_pairs(std::string const &conf)
: cvc(conf)
{
set_function_type("distancePairs");
group1 = parse_group(conf, "group1");
group2 = parse_group(conf, "group2");
x.type(colvarvalue::type_vector);
disable(f_cvc_explicit_gradient);
x.vector1d_value.resize(group1->size() * group2->size());
}
colvar::distance_pairs::distance_pairs()
{
set_function_type("distancePairs");
disable(f_cvc_explicit_gradient);
x.type(colvarvalue::type_vector);
}
void colvar::distance_pairs::calc_value()
{
x.vector1d_value.resize(group1->size() * group2->size());
if (!is_enabled(f_cvc_pbc_minimum_image)) {
size_t i1, i2;
for (i1 = 0; i1 < group1->size(); i1++) {
for (i2 = 0; i2 < group2->size(); i2++) {
cvm::rvector const dv = (*group2)[i2].pos - (*group1)[i1].pos;
cvm::real const d = dv.norm();
x.vector1d_value[i1*group2->size() + i2] = d;
(*group1)[i1].grad = -1.0 * dv.unit();
(*group2)[i2].grad = dv.unit();
}
}
} else {
size_t i1, i2;
for (i1 = 0; i1 < group1->size(); i1++) {
for (i2 = 0; i2 < group2->size(); i2++) {
cvm::rvector const dv = cvm::position_distance((*group1)[i1].pos,
(*group2)[i2].pos);
cvm::real const d = dv.norm();
x.vector1d_value[i1*group2->size() + i2] = d;
(*group1)[i1].grad = -1.0 * dv.unit();
(*group2)[i2].grad = dv.unit();
}
}
}
}
void colvar::distance_pairs::calc_gradients()
{
// will be calculated on the fly in apply_force()
}
void colvar::distance_pairs::apply_force(colvarvalue const &force)
{
if (!is_enabled(f_cvc_pbc_minimum_image)) {
size_t i1, i2;
for (i1 = 0; i1 < group1->size(); i1++) {
for (i2 = 0; i2 < group2->size(); i2++) {
cvm::rvector const dv = (*group2)[i2].pos - (*group1)[i1].pos;
(*group1)[i1].apply_force(force[i1*group2->size() + i2] * (-1.0) * dv.unit());
(*group2)[i2].apply_force(force[i1*group2->size() + i2] * dv.unit());
}
}
} else {
size_t i1, i2;
for (i1 = 0; i1 < group1->size(); i1++) {
for (i2 = 0; i2 < group2->size(); i2++) {
cvm::rvector const dv = cvm::position_distance((*group1)[i1].pos,
(*group2)[i2].pos);
(*group1)[i1].apply_force(force[i1*group2->size() + i2] * (-1.0) * dv.unit());
(*group2)[i2].apply_force(force[i1*group2->size() + i2] * dv.unit());
}
}
}
}
colvar::dipole_magnitude::dipole_magnitude(std::string const &conf)
: cvc(conf)
{
set_function_type("dipoleMagnitude");
atoms = parse_group(conf, "atoms");
init_total_force_params(conf);
x.type(colvarvalue::type_scalar);
}
colvar::dipole_magnitude::dipole_magnitude(cvm::atom const &a1)
{
set_function_type("dipoleMagnitude");
atoms = new cvm::atom_group(std::vector<cvm::atom>(1, a1));
register_atom_group(atoms);
x.type(colvarvalue::type_scalar);
}
colvar::dipole_magnitude::dipole_magnitude()
{
set_function_type("dipoleMagnitude");
x.type(colvarvalue::type_scalar);
}
void colvar::dipole_magnitude::calc_value()
{
cvm::atom_pos const atomsCom = atoms->center_of_mass();
atoms->calc_dipole(atomsCom);
dipoleV = atoms->dipole();
x.real_value = dipoleV.norm();
}
void colvar::dipole_magnitude::calc_gradients()
{
cvm::real const aux1 = atoms->total_charge/atoms->total_mass;
cvm::atom_pos const dipVunit = dipoleV.unit();
for (cvm::atom_iter ai = atoms->begin(); ai != atoms->end(); ai++) {
ai->grad = (ai->charge - aux1*ai->mass) * dipVunit;
}
}
void colvar::dipole_magnitude::apply_force(colvarvalue const &force)
{
if (!atoms->noforce) {
atoms->apply_colvar_force(force.real_value);
}
}
simple_scalar_dist_functions(dipole_magnitude)
colvar::gyration::gyration(std::string const &conf)
: cvc(conf)
{
set_function_type("gyration");
init_as_distance();
provide(f_cvc_inv_gradient);
provide(f_cvc_Jacobian);
atoms = parse_group(conf, "atoms");
if (atoms->b_user_defined_fit) {
cvm::log("WARNING: explicit fitting parameters were provided for atom group \"atoms\".\n");
} else {
atoms->enable(f_ag_center);
atoms->ref_pos.assign(1, cvm::atom_pos(0.0, 0.0, 0.0));
atoms->fit_gradients.assign(atoms->size(), cvm::rvector(0.0, 0.0, 0.0));
}
}
void colvar::gyration::calc_value()
{
x.real_value = 0.0;
for (cvm::atom_iter ai = atoms->begin(); ai != atoms->end(); ai++) {
x.real_value += (ai->pos).norm2();
}
x.real_value = cvm::sqrt(x.real_value / cvm::real(atoms->size()));
}
void colvar::gyration::calc_gradients()
{
cvm::real const drdx = 1.0/(cvm::real(atoms->size()) * x.real_value);
for (cvm::atom_iter ai = atoms->begin(); ai != atoms->end(); ai++) {
ai->grad = drdx * ai->pos;
}
}
void colvar::gyration::calc_force_invgrads()
{
atoms->read_total_forces();
cvm::real const dxdr = 1.0/x.real_value;
ft.real_value = 0.0;
for (cvm::atom_iter ai = atoms->begin(); ai != atoms->end(); ai++) {
ft.real_value += dxdr * ai->pos * ai->total_force;
}
}
void colvar::gyration::calc_Jacobian_derivative()
{
jd = x.real_value ? (3.0 * cvm::real(atoms->size()) - 4.0) / x.real_value : 0.0;
}
void colvar::gyration::apply_force(colvarvalue const &force)
{
if (!atoms->noforce)
atoms->apply_colvar_force(force.real_value);
}
simple_scalar_dist_functions(gyration)
colvar::inertia::inertia(std::string const &conf)
: gyration(conf)
{
set_function_type("inertia");
init_as_distance();
}
void colvar::inertia::calc_value()
{
x.real_value = 0.0;
for (cvm::atom_iter ai = atoms->begin(); ai != atoms->end(); ai++) {
x.real_value += (ai->pos).norm2();
}
}
void colvar::inertia::calc_gradients()
{
for (cvm::atom_iter ai = atoms->begin(); ai != atoms->end(); ai++) {
ai->grad = 2.0 * ai->pos;
}
}
void colvar::inertia::apply_force(colvarvalue const &force)
{
if (!atoms->noforce)
atoms->apply_colvar_force(force.real_value);
}
simple_scalar_dist_functions(inertia_z)
colvar::inertia_z::inertia_z(std::string const &conf)
: inertia(conf)
{
set_function_type("inertiaZ");
init_as_distance();
if (get_keyval(conf, "axis", axis, cvm::rvector(0.0, 0.0, 1.0))) {
if (axis.norm2() == 0.0) {
cvm::error("Axis vector is zero!", COLVARS_INPUT_ERROR);
return;
}
if (axis.norm2() != 1.0) {
axis = axis.unit();
cvm::log("The normalized axis is: "+cvm::to_str(axis)+".\n");
}
}
}
void colvar::inertia_z::calc_value()
{
x.real_value = 0.0;
for (cvm::atom_iter ai = atoms->begin(); ai != atoms->end(); ai++) {
cvm::real const iprod = ai->pos * axis;
x.real_value += iprod * iprod;
}
}
void colvar::inertia_z::calc_gradients()
{
for (cvm::atom_iter ai = atoms->begin(); ai != atoms->end(); ai++) {
ai->grad = 2.0 * (ai->pos * axis) * axis;
}
}
void colvar::inertia_z::apply_force(colvarvalue const &force)
{
if (!atoms->noforce)
atoms->apply_colvar_force(force.real_value);
}
simple_scalar_dist_functions(inertia)
colvar::rmsd::rmsd(std::string const &conf)
: cvc(conf)
{
set_function_type("rmsd");
init_as_distance();
provide(f_cvc_inv_gradient);
atoms = parse_group(conf, "atoms");
if (!atoms || atoms->size() == 0) {
cvm::error("Error: \"atoms\" must contain at least 1 atom to compute RMSD.");
return;
}
bool b_Jacobian_derivative = true;
if (atoms->fitting_group != NULL && b_Jacobian_derivative) {
cvm::log("The option \"fittingGroup\" (alternative group for fitting) was enabled: "
"Jacobian derivatives of the RMSD will not be calculated.\n");
b_Jacobian_derivative = false;
}
if (b_Jacobian_derivative) provide(f_cvc_Jacobian);
// the following is a simplified version of the corresponding atom group options;
// we need this because the reference coordinates defined inside the atom group
// may be used only for fitting, and even more so if fitting_group is used
if (get_keyval(conf, "refPositions", ref_pos, ref_pos)) {
cvm::log("Using reference positions from configuration file to calculate the variable.\n");
if (ref_pos.size() != atoms->size()) {
cvm::error("Error: the number of reference positions provided ("+
cvm::to_str(ref_pos.size())+
") does not match the number of atoms of group \"atoms\" ("+
cvm::to_str(atoms->size())+").\n");
return;
}
} else { // Only look for ref pos file if ref positions not already provided
std::string ref_pos_file;
if (get_keyval(conf, "refPositionsFile", ref_pos_file, std::string(""))) {
if (ref_pos.size()) {
cvm::error("Error: cannot specify \"refPositionsFile\" and "
"\"refPositions\" at the same time.\n");
return;
}
std::string ref_pos_col;
double ref_pos_col_value=0.0;
if (get_keyval(conf, "refPositionsCol", ref_pos_col, std::string(""))) {
// if provided, use PDB column to select coordinates
bool found = get_keyval(conf, "refPositionsColValue", ref_pos_col_value, 0.0);
if (found && ref_pos_col_value==0.0) {
cvm::error("Error: refPositionsColValue, "
"if provided, must be non-zero.\n");
return;
}
}
ref_pos.resize(atoms->size());
cvm::load_coords(ref_pos_file.c_str(), &ref_pos, atoms,
ref_pos_col, ref_pos_col_value);
} else {
cvm::error("Error: no reference positions for RMSD; use either refPositions of refPositionsFile.");
return;
}
}
if (ref_pos.size() != atoms->size()) {
cvm::error("Error: found " + cvm::to_str(ref_pos.size()) +
" reference positions for RMSD; expected " + cvm::to_str(atoms->size()));
return;
}
if (atoms->b_user_defined_fit) {
cvm::log("WARNING: explicit fitting parameters were provided for atom group \"atoms\".\n");
} else {
// Default: fit everything
cvm::log("Enabling \"centerToReference\" and \"rotateToReference\", to minimize RMSD before calculating it as a variable: "
"if this is not the desired behavior, disable them explicitly within the \"atoms\" block.\n");
atoms->enable(f_ag_center);
atoms->enable(f_ag_rotate);
// default case: reference positions for calculating the rmsd are also those used
// for fitting
atoms->ref_pos = ref_pos;
atoms->center_ref_pos();
cvm::log("This is a standard minimum RMSD, derivatives of the optimal rotation "
"will not be computed as they cancel out in the gradients.");
atoms->disable(f_ag_fit_gradients);
// request the calculation of the derivatives of the rotation defined by the atom group
atoms->rot.request_group1_gradients(atoms->size());
// request derivatives of optimal rotation wrt reference coordinates for Jacobian:
// this is only required for ABF, but we do both groups here for better caching
atoms->rot.request_group2_gradients(atoms->size());
}
std::string perm_conf;
size_t pos = 0; // current position in config string
n_permutations = 1;
while (key_lookup(conf, "atomPermutation", &perm_conf, &pos)) {
std::vector<size_t> perm;
if (perm_conf.size()) {
std::istringstream is(perm_conf);
size_t index;
while (is >> index) {
std::vector<int> const &ids = atoms->ids();
size_t const ia = std::find(ids.begin(), ids.end(), index-1) - ids.begin();
if (ia == atoms->size()) {
cvm::error("Error: atom id " + cvm::to_str(index) +
" is not a member of group \"atoms\".");
return;
}
if (std::find(perm.begin(), perm.end(), ia) != perm.end()) {
cvm::error("Error: atom id " + cvm::to_str(index) +
" is mentioned more than once in atomPermutation list.");
return;
}
perm.push_back(ia);
}
if (perm.size() != atoms->size()) {
cvm::error("Error: symmetry permutation in input contains " + cvm::to_str(perm.size()) +
" indices, but group \"atoms\" contains " + cvm::to_str(atoms->size()) + " atoms.");
return;
}
cvm::log("atomPermutation = " + cvm::to_str(perm));
n_permutations++;
// Record a copy of reference positions in new order
for (size_t ia = 0; ia < atoms->size(); ia++) {
ref_pos.push_back(ref_pos[perm[ia]]);
}
}
}
}
void colvar::rmsd::calc_value()
{
// rotational-translational fit is handled by the atom group
x.real_value = 0.0;
for (size_t ia = 0; ia < atoms->size(); ia++) {
x.real_value += ((*atoms)[ia].pos - ref_pos[ia]).norm2();
}
best_perm_index = 0;
// Compute sum of squares for each symmetry permutation of atoms, keep the smallest
size_t ref_pos_index = atoms->size();
for (size_t ip = 1; ip < n_permutations; ip++) {
cvm::real value = 0.0;
for (size_t ia = 0; ia < atoms->size(); ia++) {
value += ((*atoms)[ia].pos - ref_pos[ref_pos_index++]).norm2();
}
if (value < x.real_value) {
x.real_value = value;
best_perm_index = ip;
}
}
x.real_value /= cvm::real(atoms->size()); // MSD
x.real_value = cvm::sqrt(x.real_value);
}
void colvar::rmsd::calc_gradients()
{
cvm::real const drmsddx2 = (x.real_value > 0.0) ?
0.5 / (x.real_value * cvm::real(atoms->size())) :
0.0;
// Use the appropriate symmetry permutation of reference positions to calculate gradients
size_t const start = atoms->size() * best_perm_index;
for (size_t ia = 0; ia < atoms->size(); ia++) {
(*atoms)[ia].grad = (drmsddx2 * 2.0 * ((*atoms)[ia].pos - ref_pos[start + ia]));
}
}
void colvar::rmsd::apply_force(colvarvalue const &force)
{
if (!atoms->noforce)
atoms->apply_colvar_force(force.real_value);
}
void colvar::rmsd::calc_force_invgrads()
{
atoms->read_total_forces();
ft.real_value = 0.0;
// Note: gradient square norm is 1/N_atoms
for (size_t ia = 0; ia < atoms->size(); ia++) {
ft.real_value += (*atoms)[ia].grad * (*atoms)[ia].total_force;
}
ft.real_value *= atoms->size();
}
void colvar::rmsd::calc_Jacobian_derivative()
{
// divergence of the rotated coordinates (including only derivatives of the rotation matrix)
cvm::real rotation_term = 0.0;
// The rotation term only applies is coordinates are rotated
if (atoms->is_enabled(f_ag_rotate)) {
// gradient of the rotation matrix
cvm::matrix2d<cvm::rvector> grad_rot_mat(3, 3);
// gradients of products of 2 quaternion components
cvm::rvector g11, g22, g33, g01, g02, g03, g12, g13, g23;
for (size_t ia = 0; ia < atoms->size(); ia++) {
// Gradient of optimal quaternion wrt current Cartesian position
cvm::vector1d<cvm::rvector> &dq = atoms->rot.dQ0_1[ia];
g11 = 2.0 * (atoms->rot.q)[1]*dq[1];
g22 = 2.0 * (atoms->rot.q)[2]*dq[2];
g33 = 2.0 * (atoms->rot.q)[3]*dq[3];
g01 = (atoms->rot.q)[0]*dq[1] + (atoms->rot.q)[1]*dq[0];
g02 = (atoms->rot.q)[0]*dq[2] + (atoms->rot.q)[2]*dq[0];
g03 = (atoms->rot.q)[0]*dq[3] + (atoms->rot.q)[3]*dq[0];
g12 = (atoms->rot.q)[1]*dq[2] + (atoms->rot.q)[2]*dq[1];
g13 = (atoms->rot.q)[1]*dq[3] + (atoms->rot.q)[3]*dq[1];
g23 = (atoms->rot.q)[2]*dq[3] + (atoms->rot.q)[3]*dq[2];
// Gradient of the rotation matrix wrt current Cartesian position
grad_rot_mat[0][0] = -2.0 * (g22 + g33);
grad_rot_mat[1][0] = 2.0 * (g12 + g03);
grad_rot_mat[2][0] = 2.0 * (g13 - g02);
grad_rot_mat[0][1] = 2.0 * (g12 - g03);
grad_rot_mat[1][1] = -2.0 * (g11 + g33);
grad_rot_mat[2][1] = 2.0 * (g01 + g23);
grad_rot_mat[0][2] = 2.0 * (g02 + g13);
grad_rot_mat[1][2] = 2.0 * (g23 - g01);
grad_rot_mat[2][2] = -2.0 * (g11 + g22);
cvm::atom_pos &y = ref_pos[ia];
for (size_t alpha = 0; alpha < 3; alpha++) {
for (size_t beta = 0; beta < 3; beta++) {
rotation_term += grad_rot_mat[beta][alpha][alpha] * y[beta];
// Note: equation was derived for inverse rotation (see colvars paper)
// so here the matrix is transposed
// (eq would give divergence += grad_rot_mat[alpha][beta][alpha] * y[beta];)
}
}
}
}
// The translation term only applies is coordinates are centered
cvm::real translation_term = atoms->is_enabled(f_ag_center) ? 3.0 : 0.0;
jd.real_value = x.real_value > 0.0 ?
(3.0 * atoms->size() - 1.0 - translation_term - rotation_term) / x.real_value :
0.0;
}
simple_scalar_dist_functions(rmsd)
colvar::eigenvector::eigenvector(std::string const &conf)
: cvc(conf)
{
set_function_type("eigenvector");
provide(f_cvc_inv_gradient);
provide(f_cvc_Jacobian);
x.type(colvarvalue::type_scalar);
atoms = parse_group(conf, "atoms");
{
bool const b_inline = get_keyval(conf, "refPositions", ref_pos, ref_pos);
if (b_inline) {
cvm::log("Using reference positions from input file.\n");
if (ref_pos.size() != atoms->size()) {
cvm::error("Error: reference positions do not "
"match the number of requested atoms.\n");
return;
}
}
std::string file_name;
if (get_keyval(conf, "refPositionsFile", file_name)) {
if (b_inline) {
cvm::error("Error: refPositions and refPositionsFile cannot be specified at the same time.\n");
return;
}
std::string file_col;
double file_col_value=0.0;
if (get_keyval(conf, "refPositionsCol", file_col, std::string(""))) {
// use PDB flags if column is provided
bool found = get_keyval(conf, "refPositionsColValue", file_col_value, 0.0);
if (found && file_col_value==0.0) {
cvm::error("Error: refPositionsColValue, "
"if provided, must be non-zero.\n");
return;
}
}
ref_pos.resize(atoms->size());
cvm::load_coords(file_name.c_str(), &ref_pos, atoms,
file_col, file_col_value);
}
}
if (ref_pos.size() == 0) {
cvm::error("Error: reference positions were not provided.\n", COLVARS_INPUT_ERROR);
return;
}
if (ref_pos.size() != atoms->size()) {
cvm::error("Error: reference positions do not "
"match the number of requested atoms.\n", COLVARS_INPUT_ERROR);
return;
}
// save for later the geometric center of the provided positions (may not be the origin)
cvm::rvector ref_pos_center(0.0, 0.0, 0.0);
for (size_t i = 0; i < atoms->size(); i++) {
ref_pos_center += ref_pos[i];
}
ref_pos_center *= 1.0 / atoms->size();
if (atoms->b_user_defined_fit) {
cvm::log("WARNING: explicit fitting parameters were provided for atom group \"atoms\".\n");
} else {
// default: fit everything
cvm::log("Enabling \"centerToReference\" and \"rotateToReference\", to minimize RMSD before calculating the vector projection: "
"if this is not the desired behavior, disable them explicitly within the \"atoms\" block.\n");
atoms->enable(f_ag_center);
atoms->enable(f_ag_rotate);
atoms->ref_pos = ref_pos;
atoms->center_ref_pos();
atoms->disable(f_ag_fit_gradients); // cancel out if group is fitted on itself
// and cvc is translationally invariant
// request the calculation of the derivatives of the rotation defined by the atom group
atoms->rot.request_group1_gradients(atoms->size());
// request derivatives of optimal rotation wrt reference coordinates for Jacobian:
// this is only required for ABF, but we do both groups here for better caching
atoms->rot.request_group2_gradients(atoms->size());
}
{
bool const b_inline = get_keyval(conf, "vector", eigenvec, eigenvec);
// now load the eigenvector
if (b_inline) {
cvm::log("Using vector components from input file.\n");
if (eigenvec.size() != atoms->size()) {
cvm::error("Error: vector components do not "
"match the number of requested atoms->\n");
return;
}
}
std::string file_name;
if (get_keyval(conf, "vectorFile", file_name)) {
if (b_inline) {
cvm::error("Error: vector and vectorFile cannot be specified at the same time.\n");
return;
}
std::string file_col;
double file_col_value=0.0;
if (get_keyval(conf, "vectorCol", file_col, std::string(""))) {
// use PDB flags if column is provided
bool found = get_keyval(conf, "vectorColValue", file_col_value, 0.0);
if (found && file_col_value==0.0) {
cvm::error("Error: vectorColValue, if provided, must be non-zero.\n");
return;
}
}
eigenvec.resize(atoms->size());
cvm::load_coords(file_name.c_str(), &eigenvec, atoms,
file_col, file_col_value);
}
}
if (!ref_pos.size() || !eigenvec.size()) {
cvm::error("Error: both reference coordinates"
"and eigenvector must be defined.\n");
return;
}
cvm::atom_pos eig_center(0.0, 0.0, 0.0);
for (size_t eil = 0; eil < atoms->size(); eil++) {
eig_center += eigenvec[eil];
}
eig_center *= 1.0 / atoms->size();
cvm::log("Geometric center of the provided vector: "+cvm::to_str(eig_center)+"\n");
bool b_difference_vector = false;
get_keyval(conf, "differenceVector", b_difference_vector, false);
if (b_difference_vector) {
if (atoms->is_enabled(f_ag_center)) {
// both sets should be centered on the origin for fitting
for (size_t i = 0; i < atoms->size(); i++) {
eigenvec[i] -= eig_center;
ref_pos[i] -= ref_pos_center;
}
}
if (atoms->is_enabled(f_ag_rotate)) {
atoms->rot.calc_optimal_rotation(eigenvec, ref_pos);
for (size_t i = 0; i < atoms->size(); i++) {
eigenvec[i] = atoms->rot.rotate(eigenvec[i]);
}
}
cvm::log("\"differenceVector\" is on: subtracting the reference positions from the provided vector: v = x_vec - x_ref.\n");
for (size_t i = 0; i < atoms->size(); i++) {
eigenvec[i] -= ref_pos[i];
}
if (atoms->is_enabled(f_ag_center)) {
// bring back the ref positions to where they were
for (size_t i = 0; i < atoms->size(); i++) {
ref_pos[i] += ref_pos_center;
}
}
} else {
cvm::log("Centering the provided vector to zero.\n");
for (size_t i = 0; i < atoms->size(); i++) {
eigenvec[i] -= eig_center;
}
}
// eigenvec_invnorm2 is used when computing inverse gradients
eigenvec_invnorm2 = 0.0;
for (size_t ein = 0; ein < atoms->size(); ein++) {
eigenvec_invnorm2 += eigenvec[ein].norm2();
}
eigenvec_invnorm2 = 1.0 / eigenvec_invnorm2;
// Vector normalization overrides the default normalization for differenceVector
bool normalize = false;
get_keyval(conf, "normalizeVector", normalize, normalize);
if (normalize) {
cvm::log("Normalizing the vector so that |v| = 1.\n");
for (size_t i = 0; i < atoms->size(); i++) {
eigenvec[i] *= cvm::sqrt(eigenvec_invnorm2);
}
eigenvec_invnorm2 = 1.0;
} else if (b_difference_vector) {
cvm::log("Normalizing the vector so that the norm of the projection |v ⋅ (x_vec - x_ref)| = 1.\n");
for (size_t i = 0; i < atoms->size(); i++) {
eigenvec[i] *= eigenvec_invnorm2;
}
eigenvec_invnorm2 = 1.0/eigenvec_invnorm2;
} else {
cvm::log("The norm of the vector is |v| = "+
cvm::to_str(1.0/cvm::sqrt(eigenvec_invnorm2))+".\n");
}
}
void colvar::eigenvector::calc_value()
{
x.real_value = 0.0;
for (size_t i = 0; i < atoms->size(); i++) {
x.real_value += ((*atoms)[i].pos - ref_pos[i]) * eigenvec[i];
}
}
void colvar::eigenvector::calc_gradients()
{
for (size_t ia = 0; ia < atoms->size(); ia++) {
(*atoms)[ia].grad = eigenvec[ia];
}
}
void colvar::eigenvector::apply_force(colvarvalue const &force)
{
if (!atoms->noforce)
atoms->apply_colvar_force(force.real_value);
}
void colvar::eigenvector::calc_force_invgrads()
{
atoms->read_total_forces();
ft.real_value = 0.0;
for (size_t ia = 0; ia < atoms->size(); ia++) {
ft.real_value += eigenvec_invnorm2 * (*atoms)[ia].grad *
(*atoms)[ia].total_force;
}
}
void colvar::eigenvector::calc_Jacobian_derivative()
{
// gradient of the rotation matrix
cvm::matrix2d<cvm::rvector> grad_rot_mat(3, 3);
cvm::quaternion &quat0 = atoms->rot.q;
// gradients of products of 2 quaternion components
cvm::rvector g11, g22, g33, g01, g02, g03, g12, g13, g23;
cvm::real sum = 0.0;
for (size_t ia = 0; ia < atoms->size(); ia++) {
// Gradient of optimal quaternion wrt current Cartesian position
// trick: d(R^-1)/dx = d(R^t)/dx = (dR/dx)^t
// we can just transpose the derivatives of the direct matrix
cvm::vector1d<cvm::rvector> &dq_1 = atoms->rot.dQ0_1[ia];
g11 = 2.0 * quat0[1]*dq_1[1];
g22 = 2.0 * quat0[2]*dq_1[2];
g33 = 2.0 * quat0[3]*dq_1[3];
g01 = quat0[0]*dq_1[1] + quat0[1]*dq_1[0];
g02 = quat0[0]*dq_1[2] + quat0[2]*dq_1[0];
g03 = quat0[0]*dq_1[3] + quat0[3]*dq_1[0];
g12 = quat0[1]*dq_1[2] + quat0[2]*dq_1[1];
g13 = quat0[1]*dq_1[3] + quat0[3]*dq_1[1];
g23 = quat0[2]*dq_1[3] + quat0[3]*dq_1[2];
// Gradient of the inverse rotation matrix wrt current Cartesian position
// (transpose of the gradient of the direct rotation)
grad_rot_mat[0][0] = -2.0 * (g22 + g33);
grad_rot_mat[0][1] = 2.0 * (g12 + g03);
grad_rot_mat[0][2] = 2.0 * (g13 - g02);
grad_rot_mat[1][0] = 2.0 * (g12 - g03);
grad_rot_mat[1][1] = -2.0 * (g11 + g33);
grad_rot_mat[1][2] = 2.0 * (g01 + g23);
grad_rot_mat[2][0] = 2.0 * (g02 + g13);
grad_rot_mat[2][1] = 2.0 * (g23 - g01);
grad_rot_mat[2][2] = -2.0 * (g11 + g22);
for (size_t i = 0; i < 3; i++) {
for (size_t j = 0; j < 3; j++) {
sum += grad_rot_mat[i][j][i] * eigenvec[ia][j];
}
}
}
jd.real_value = sum * cvm::sqrt(eigenvec_invnorm2);
}
simple_scalar_dist_functions(eigenvector)
colvar::cartesian::cartesian(std::string const &conf)
: cvc(conf)
{
set_function_type("cartesian");
atoms = parse_group(conf, "atoms");
bool use_x, use_y, use_z;
get_keyval(conf, "useX", use_x, true);
get_keyval(conf, "useY", use_y, true);
get_keyval(conf, "useZ", use_z, true);
axes.clear();
if (use_x) axes.push_back(0);
if (use_y) axes.push_back(1);
if (use_z) axes.push_back(2);
if (axes.size() == 0) {
cvm::error("Error: a \"cartesian\" component was defined with all three axes disabled.\n");
return;
}
x.type(colvarvalue::type_vector);
disable(f_cvc_explicit_gradient);
// Don't try to access atoms if creation of the atom group failed
if (atoms != NULL) x.vector1d_value.resize(atoms->size() * axes.size());
}
void colvar::cartesian::calc_value()
{
size_t const dim = axes.size();
size_t ia, j;
for (ia = 0; ia < atoms->size(); ia++) {
for (j = 0; j < dim; j++) {
x.vector1d_value[dim*ia + j] = (*atoms)[ia].pos[axes[j]];
}
}
}
void colvar::cartesian::calc_gradients()
{
// we're not using the "grad" member of each
// atom object, because it only can represent the gradient of a
// scalar colvar
}
void colvar::cartesian::apply_force(colvarvalue const &force)
{
size_t const dim = axes.size();
size_t ia, j;
if (!atoms->noforce) {
cvm::rvector f;
for (ia = 0; ia < atoms->size(); ia++) {
for (j = 0; j < dim; j++) {
f[axes[j]] = force.vector1d_value[dim*ia + j];
}
(*atoms)[ia].apply_force(f);
}
}
}