org.biojava.nbio.structure.symmetry.axis.RotationAxisAligner Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of biojava-structure Show documentation
Show all versions of biojava-structure Show documentation
The protein structure modules of BioJava.
The newest version!
/*
* BioJava development code
*
* This code may be freely distributed and modified under the
* terms of the GNU Lesser General Public Licence. This should
* be distributed with the code. If you do not have a copy,
* see:
*
* http://www.gnu.org/copyleft/lesser.html
*
* Copyright for this code is held jointly by the individual
* authors. These should be listed in @author doc comments.
*
* For more information on the BioJava project and its aims,
* or to join the biojava-l mailing list, visit the home page
* at:
*
* http://www.biojava.org/
*
*/
package org.biojava.nbio.structure.symmetry.axis;
import org.biojava.nbio.structure.geometry.CalcPoint;
import org.biojava.nbio.structure.geometry.MomentsOfInertia;
import org.biojava.nbio.structure.symmetry.core.QuatSymmetryResults;
import org.biojava.nbio.structure.symmetry.core.Rotation;
import org.biojava.nbio.structure.symmetry.core.RotationGroup;
import org.biojava.nbio.structure.symmetry.core.QuatSymmetrySubunits;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.vecmath.*;
import java.util.*;
public class RotationAxisAligner extends AxisAligner{
private static final Logger logger = LoggerFactory
.getLogger(RotationAxisAligner.class);
private static final Vector3d X_AXIS = new Vector3d(1,0,0);
private static final Vector3d Y_AXIS = new Vector3d(0,1,0);
private static final Vector3d Z_AXIS = new Vector3d(0,0,1);
private QuatSymmetrySubunits subunits = null;
private RotationGroup rotationGroup = null;
private Matrix4d transformationMatrix = new Matrix4d();
private Matrix4d reverseTransformationMatrix = new Matrix4d();
private Vector3d referenceVector = new Vector3d();
private Vector3d principalRotationVector = new Vector3d();
private Vector3d[] principalAxesOfInertia = null;
List> alignedOrbits = null;
private Vector3d minBoundary = new Vector3d();
private Vector3d maxBoundary = new Vector3d();
private double xyRadiusMax = Double.MIN_VALUE;
boolean modified = true;
public RotationAxisAligner(QuatSymmetryResults results) {
this.subunits = new QuatSymmetrySubunits(results.getSubunitClusters());
this.rotationGroup = results.getRotationGroup();
if (subunits == null) {
throw new IllegalArgumentException("AxisTransformation: Subunits are null");
} else if (rotationGroup == null) {
throw new IllegalArgumentException("AxisTransformation: RotationGroup is null");
} else if (subunits.getSubunitCount() == 0) {
throw new IllegalArgumentException("AxisTransformation: Subunits is empty");
} else if (rotationGroup.getOrder() == 0) {
throw new IllegalArgumentException("AxisTransformation: RotationGroup is empty");
}
}
/* (non-Javadoc)
* @see org.biojava.nbio.structure.quaternary.core.AxisAligner#getTransformation()
*/
@Override
public String getSymmetry() {
run();
return rotationGroup.getPointGroup();
}
@Override
public Matrix4d getTransformation() {
run();
return transformationMatrix;
}
@Override
public Matrix3d getRotationMatrix() {
run();
Matrix3d m = new Matrix3d();
transformationMatrix.getRotationScale(m);
return m;
}
@Override
public Matrix4d getReverseTransformation() {
run();
return reverseTransformationMatrix;
}
@Override
public Vector3d getPrincipalRotationAxis() {
run();
return principalRotationVector;
}
@Override
public Vector3d getRotationReferenceAxis() {
run();
return referenceVector;
}
@Override
public Vector3d[] getPrincipalAxesOfInertia() {
run();
return principalAxesOfInertia;
}
@Override
public Vector3d getDimension() {
run();
Vector3d dimension = new Vector3d();
dimension.sub(maxBoundary, minBoundary);
dimension.scale(0.5);
return dimension;
}
/**
* Returns the radius for drawing the minor rotation axis in the xy-plane
* @return double radius in xy-plane
*/
@Override
public double getRadius() {
run();
return xyRadiusMax;
}
/**
* Returns a transformation matrix transform polyhedra for Cn structures.
* The center in this matrix is the geometric center, rather then the centroid.
* In Cn structures those are usually not the same.
* @return
*/
@Override
public Matrix4d getGeometicCenterTransformation() {
run();
Matrix4d geometricCentered = new Matrix4d(reverseTransformationMatrix);
geometricCentered.setTranslation(new Vector3d(getGeometricCenter()));
return geometricCentered;
}
/**
* Returns the geometric center of polyhedron. In the case of the Cn
* point group, the centroid and geometric center are usually not
* identical.
* @return
*/
@Override
public Point3d getGeometricCenter() {
run();
Point3d geometricCenter = new Point3d();
Vector3d translation = new Vector3d();
reverseTransformationMatrix.get(translation);
// calculate adjustment around z-axis and transform adjustment to
// original coordinate frame with the reverse transformation
if (rotationGroup.getPointGroup().startsWith("C")) {
Vector3d corr = new Vector3d(0,0, minBoundary.z+getDimension().z);
reverseTransformationMatrix.transform(corr);
geometricCenter.set(corr);
}
geometricCenter.add(translation);
return geometricCenter;
}
@Override
public Point3d getCentroid() {
return new Point3d(subunits.getCentroid());
}
@Override
public QuatSymmetrySubunits getSubunits() {
return subunits;
}
public RotationGroup getRotationGroup() {
return rotationGroup;
}
@Override
public List> getOrbits() {
return alignedOrbits;
}
/**
* @return
*/
private void run () {
if (modified) {
calcPrincipalRotationVector();
calcPrincipalAxes();
// initial alignment with draft reference axis
calcReferenceVector();
calcTransformation();
// refine ref. axis for cyclic and dihedral systems
if ((rotationGroup.getPointGroup().startsWith("C") &&
!rotationGroup.getPointGroup().startsWith("C2")) ||
(rotationGroup.getPointGroup().startsWith("D") &&
!rotationGroup.getPointGroup().startsWith("D2"))
) {
refineReferenceVector();
calcTransformation();
}
calcReverseTransformation();
calcBoundaries();
if (! "Helical".equals(rotationGroup.getPointGroup())) {
calcAlignedOrbits();
}
modified = false;
}
}
/**
* Returns a list of orbits (an orbit is a cyclic permutation of subunit indices that are related
* by a rotation around the principal rotation axis) ordered from the +z direction to the -z direction (z-depth).
* Within an orbit, subunit indices are ordered with a clockwise rotation around the z-axis.
* @return list of orbits ordered by z-depth
*/
private void calcAlignedOrbits() {
Map> depthMap = new TreeMap<>();
double[] depth = getSubunitZDepth();
alignedOrbits = calcOrbits();
// calculate the mean depth of orbit along z-axis
for (List orbit: alignedOrbits) {
// calculate the mean depth along z-axis for each orbit
double meanDepth = 0;
for (int subunit: orbit) {
meanDepth += depth[subunit];
}
meanDepth /= orbit.size();
if (depthMap.get(meanDepth) != null) {
// System.out.println("Conflict in depthMap");
meanDepth += 0.01;
}
depthMap.put(meanDepth, orbit);
}
// now fill orbits back into list ordered by depth
alignedOrbits.clear();
for (List orbit: depthMap.values()) {
// order subunit in a clockwise rotation around the z-axis
/// starting at the 12 O-clock position (+y position)
alignWithReferenceAxis(orbit);
alignedOrbits.add(orbit);
}
}
/**
* Returns an ordered list of subunit ids (orbit) in such a way that the subunit
* indices start at the 12 o-clock (+y axis) and proceed in a clockwise direction
* to the 11 o-clock position to close the "orbit".
*
* @param orbit list of subunit indices that are transformed into each other by a rotation
* @return list of subunit indices ordered in a clockwise direction
*/
private List alignWithReferenceAxis(List orbit) {
int n = subunits.getSubunitCount();
int fold = rotationGroup.getRotation(0).getFold();
if (fold < 2) {
return orbit;
}
Vector3d probe = new Vector3d();
double dotMin1 = Double.MIN_VALUE;
double dotMin2 = Double.MIN_VALUE;
int index1 = 0;
int index2 = 0;
Vector3d Y1 = new Vector3d(0,1,0);
Vector3d Y2 = new Vector3d(0,1,0);
Matrix3d m = new Matrix3d();
double angle = -2*Math.PI/fold;
m.rotZ(0.1*angle); // add small offset, since two subunits may be equidistant to the y-axis
m.transform(Y1);
m.rotZ(1.1*angle);
m.transform(Y2);
// transform subunit centers into z-aligned position and calculate
// width in xy direction.
for (int i: orbit) {
Point3d p = subunits.getCenters().get(i);
probe.set(p);
transformationMatrix.transform(probe);
// find subunit that lines up with y-axis
double dot1 = Y1.dot(probe);
if (dot1 > dotMin1) {
dotMin1 = dot1;
index1 = i;
}
// find next subunit (rotated by one fold around z-axis - clockwise)
double dot2 = Y2.dot(probe);
if (dot2 > dotMin2) {
dotMin2 = dot2;
index2 = i;
}
}
// System.out.println("Index1/2: " + index1 + " - " + index2);
// System.out.println("Orbit0: " + orbit);
// order subunit indices in a clockwise orientation around the z-axis
// bring subunit into position 0
for (int i = 0; i < n; i++) {
if (orbit.get(0) == index1) {
break;
}
Collections.rotate(orbit,1);
}
// System.out.println("Orbit1: " + orbit);
// bring second subunit onto position 1
if (orbit.get(1) == index2) {
return orbit;
}
Collections.reverse(orbit.subList(1, orbit.size()));
if (orbit.get(1) != index2) {
logger.warn("alignWithReferenceAxis failed");
}
// System.out.println("Orbit2: " + orbit);
return orbit;
}
private void calcTransformation() {
if ("C1".equals(rotationGroup.getPointGroup())) {
calcTransformationByInertiaAxes();
} else {
calcTransformationBySymmetryAxes();
}
// make sure this value is zero. On Linux this value is 0.
transformationMatrix.setElement(3, 3, 1.0);
}
private void calcReverseTransformation() {
reverseTransformationMatrix.invert(transformationMatrix);
}
private void calcTransformationBySymmetryAxes() {
Vector3d[] axisVectors = new Vector3d[2];
axisVectors[0] = new Vector3d(principalRotationVector);
axisVectors[1] = new Vector3d(referenceVector);
// y,z axis centered at the centroid of the subunits
Vector3d[] referenceVectors = new Vector3d[2];
referenceVectors[0] = new Vector3d(Z_AXIS);
referenceVectors[1] = new Vector3d(Y_AXIS);
transformationMatrix = alignAxes(axisVectors, referenceVectors);
// combine with translation
Matrix4d combined = new Matrix4d();
combined.setIdentity();
Vector3d trans = new Vector3d(subunits.getCentroid());
trans.negate();
combined.setTranslation(trans);
transformationMatrix.mul(combined);
// for cyclic geometry, set a canonical view for the Z direction
if (rotationGroup.getPointGroup().startsWith("C")) {
calcZDirection();
}
}
private void calcTransformationByInertiaAxes() {
Vector3d[] axisVectors = new Vector3d[2];
axisVectors[0] = new Vector3d(principalAxesOfInertia[0]);
axisVectors[1] = new Vector3d(principalAxesOfInertia[1]);
Vector3d[] referenceVectors = new Vector3d[2];
referenceVectors[0] = new Vector3d(Y_AXIS);
referenceVectors[1] = new Vector3d(X_AXIS);
// align inertia axes with y-x plane
transformationMatrix = alignAxes(axisVectors, referenceVectors);
// combine with translation
Matrix4d translation = new Matrix4d();
translation.setIdentity();
Vector3d trans = new Vector3d(subunits.getCentroid());
trans.negate();
translation.setTranslation(trans);
transformationMatrix.mul(translation);
}
/**
* Returns a transformation matrix that rotates refPoints to match
* coordPoints
* @param refPoints the points to be aligned
* @param referenceVectors
* @return
*/
private Matrix4d alignAxes(Vector3d[] axisVectors, Vector3d[] referenceVectors) {
Matrix4d m1 = new Matrix4d();
AxisAngle4d a = new AxisAngle4d();
Vector3d axis = new Vector3d();
// calculate rotation matrix to rotate refPoints[0] into coordPoints[0]
Vector3d v1 = new Vector3d(axisVectors[0]);
Vector3d v2 = new Vector3d(referenceVectors[0]);
double dot = v1.dot(v2);
if (Math.abs(dot) < 0.999) {
axis.cross(v1,v2);
axis.normalize();
a.set(axis, v1.angle(v2));
m1.set(a);
// make sure matrix element m33 is 1.0. It's 0 on Linux.
m1.setElement(3, 3, 1.0);
} else if (dot > 0) {
// parallel axis, nothing to do -> identity matrix
m1.setIdentity();
} else if (dot < 0) {
// anti-parallel axis, flip around x-axis
m1.set(flipX());
}
// apply transformation matrix to all refPoints
m1.transform(axisVectors[0]);
m1.transform(axisVectors[1]);
// calculate rotation matrix to rotate refPoints[1] into coordPoints[1]
v1 = new Vector3d(axisVectors[1]);
v2 = new Vector3d(referenceVectors[1]);
Matrix4d m2 = new Matrix4d();
dot = v1.dot(v2);
if (Math.abs(dot) < 0.999) {
axis.cross(v1,v2);
axis.normalize();
a.set(axis, v1.angle(v2));
m2.set(a);
// make sure matrix element m33 is 1.0. It's 0 on Linux.
m2.setElement(3, 3, 1.0);
} else if (dot > 0) {
// parallel axis, nothing to do -> identity matrix
m2.setIdentity();
} else if (dot < 0) {
// anti-parallel axis, flip around z-axis
m2.set(flipZ());
}
// apply transformation matrix to all refPoints
m2.transform(axisVectors[0]);
m2.transform(axisVectors[1]);
// combine the two rotation matrices
m2.mul(m1);
// the RMSD should be close to zero
Point3d[] axes = new Point3d[2];
axes[0] = new Point3d(axisVectors[0]);
axes[1] = new Point3d(axisVectors[1]);
Point3d[] ref = new Point3d[2];
ref[0] = new Point3d(referenceVectors[0]);
ref[1] = new Point3d(referenceVectors[1]);
if (CalcPoint.rmsd(axes, ref) > 0.1) {
logger.warn("AxisTransformation: axes alignment is off. RMSD: "
+ CalcPoint.rmsd(axes, ref));
}
return m2;
}
private void calcPrincipalAxes() {
MomentsOfInertia moi = new MomentsOfInertia();
for (Point3d[] list: subunits.getTraces()) {
for (Point3d p: list) {
moi.addPoint(p, 1.0);
}
}
principalAxesOfInertia = moi.getPrincipalAxes();
}
/**
* Calculates the min and max boundaries of the structure after it has been
* transformed into its canonical orientation.
*/
private void calcBoundaries() {
minBoundary.x = Double.MAX_VALUE;
maxBoundary.x = Double.MIN_VALUE;
minBoundary.y = Double.MAX_VALUE;
maxBoundary.x = Double.MIN_VALUE;
minBoundary.z = Double.MAX_VALUE;
maxBoundary.z = Double.MIN_VALUE;
Point3d probe = new Point3d();
for (Point3d[] list: subunits.getTraces()) {
for (Point3d p: list) {
probe.set(p);
transformationMatrix.transform(probe);
minBoundary.x = Math.min(minBoundary.x, probe.x);
maxBoundary.x = Math.max(maxBoundary.x, probe.x);
minBoundary.y = Math.min(minBoundary.y, probe.y);
maxBoundary.y = Math.max(maxBoundary.y, probe.y);
minBoundary.z = Math.min(minBoundary.z, probe.z);
maxBoundary.z = Math.max(maxBoundary.z, probe.z);
xyRadiusMax = Math.max(xyRadiusMax, Math.sqrt(probe.x*probe.x + probe.y * probe.y));
}
}
}
/*
* Modifies the rotation part of the transformation axis for
* a Cn symmetric complex, so that the narrower end faces the
* viewer, and the wider end faces away from the viewer. Example: 3LSV
*/
private void calcZDirection() {
calcBoundaries();
// if the longer part of the structure faces towards the back (-z direction),
// rotate around y-axis so the longer part faces the viewer (+z direction)
if (Math.abs(minBoundary.z) > Math.abs(maxBoundary.z)) {
Matrix4d rot = flipY();
rot.mul(transformationMatrix);
transformationMatrix.set(rot);
}
}
/**
*
*/
private List> getOrbitsByXYWidth() {
Map> widthMap = new TreeMap<>();
double[] width = getSubunitXYWidth();
List> orbits = calcOrbits();
// calculate the mean width of orbits in XY-plane
for (List orbit: orbits) {
double meanWidth = 0;
for (int subunit: orbit) {
meanWidth += width[subunit];
}
meanWidth /= orbit.size();
if (widthMap.get(meanWidth) != null) {
meanWidth += 0.01;
}
widthMap.put(meanWidth, orbit);
}
// now fill orbits back into list ordered by width
orbits.clear();
for (List orbit: widthMap.values()) {
orbits.add(orbit);
}
return orbits;
}
private double[] getSubunitXYWidth() {
int n = subunits.getSubunitCount();
double[] width = new double[n];
Point3d probe = new Point3d();
// transform subunit centers into z-aligned position and calculate
// width in xy direction.
for (int i = 0; i < n; i++) {
width[i] = Double.MIN_VALUE;
for (Point3d p: subunits.getTraces().get(i)) {
probe.set(p);
transformationMatrix.transform(probe);
width[i] = Math.max(width[i], Math.sqrt(probe.x*probe.x + probe.y*probe.y));
}
}
return width;
}
private double[] getSubunitZDepth() {
int n = subunits.getSubunitCount();
double[] depth = new double[n];
Point3d probe = new Point3d();
// transform subunit centers into z-aligned position and calculate
// z-coordinates (depth) along the z-axis.
for (int i = 0; i < n; i++) {
Point3d p= subunits.getCenters().get(i);
probe.set(p);
transformationMatrix.transform(probe);
depth[i] = probe.z;
}
return depth;
}
/**
* Returns a list of list of subunit ids that form an "orbit", i.e. they
* are transformed into each other during a rotation around the principal symmetry axis (z-axis)
* @return
*/
private List> calcOrbits() {
int n = subunits.getSubunitCount();
int fold = rotationGroup.getRotation(0).getFold();
List> orbits = new ArrayList<>();
boolean[] used = new boolean[n];
Arrays.fill(used, false);
for (int i = 0; i < n; i++) {
if (! used[i]) {
// determine the equivalent subunits
List orbit = new ArrayList<>(fold);
for (int j = 0; j < fold; j++) {
List permutation = rotationGroup.getRotation(j).getPermutation();
orbit.add(permutation.get(i));
used[permutation.get(i)] = true;
}
orbits.add(deconvolute(orbit));
}
}
return orbits;
}
private List deconvolute(List orbit) {
if (rotationGroup.getOrder() < 2) {
return orbit;
}
List p0 = rotationGroup.getRotation(0).getPermutation();
List p1 = rotationGroup.getRotation(1).getPermutation();
// System.out.println("deconvolute");
// System.out.println("Permutation0: " + p0);
// System.out.println("Permutation1: " + p1);
List inRotationOrder = new ArrayList<>(orbit.size());
inRotationOrder.add(orbit.get(0));
for (int i = 1; i < orbit.size(); i++) {
int current = inRotationOrder.get(i-1);
int index = p0.indexOf(current);
int next = p1.get(index);
if (!orbit.contains(next)) {
logger.warn("deconvolute: inconsistency in permuation. Returning original order");
return orbit;
}
inRotationOrder.add(next);
}
// System.out.println("In order: " + inRotationOrder);
return inRotationOrder;
}
/**
* Returns a vector along the principal rotation axis for the
* alignment of structures along the z-axis
* @return principal rotation vector
*/
private void calcPrincipalRotationVector() {
Rotation rotation = rotationGroup.getRotation(0); // the rotation around the principal axis is the first rotation
AxisAngle4d axisAngle = rotation.getAxisAngle();
principalRotationVector = new Vector3d(axisAngle.x, axisAngle.y, axisAngle.z);
}
/**
* Returns a vector perpendicular to the principal rotation vector
* for the alignment of structures in the xy-plane
* @return reference vector
*/
private void calcReferenceVector() {
referenceVector = null;
if (rotationGroup.getPointGroup().startsWith("C")) {
referenceVector = getReferenceAxisCylic();
} else if (rotationGroup.getPointGroup().startsWith("D")) {
referenceVector = getReferenceAxisDihedral();
} else if ("T".equals(rotationGroup.getPointGroup())) {
referenceVector = getReferenceAxisTetrahedral();
} else if ("O".equals(rotationGroup.getPointGroup())) {
referenceVector = getReferenceAxisOctahedral();
} else if ("I".equals(rotationGroup.getPointGroup())) {
referenceVector = getReferenceAxisIcosahedral();
} else if ("Helical".equals(rotationGroup.getPointGroup())) {
// TODO what should the reference vector be??
referenceVector = getReferenceAxisCylic();
}
if (referenceVector == null) {
logger.warn("no reference vector found. Using y-axis.");
referenceVector = new Vector3d(Y_AXIS);
}
// make sure reference vector is perpendicular principal roation vector
referenceVector = orthogonalize(principalRotationVector, referenceVector);
}
/**
* Returns a normalized vector that represents a minor rotation axis, except
* for Cn, this represents an axis orthogonal to the principal axis.
* @return minor rotation axis
*/
private void refineReferenceVector() {
referenceVector = new Vector3d(Y_AXIS);
if (rotationGroup.getPointGroup().startsWith("C")) {
referenceVector = getReferenceAxisCylicWithSubunitAlignment();
} else if (rotationGroup.getPointGroup().startsWith("D")) {
referenceVector = getReferenceAxisDihedralWithSubunitAlignment();
}
referenceVector = orthogonalize(principalRotationVector, referenceVector);
}
private Vector3d orthogonalize(Vector3d vector1, Vector3d vector2) {
double dot = vector1.dot(vector2);
Vector3d ref = new Vector3d(vector2);
// System.out.println("p.r: " + dot);
// System.out.println("Orig refVector: " + referenceVector);
if (dot < 0) {
vector2.negate();
}
vector2.cross(vector1, vector2);
// System.out.println("Intermed. refVector: " + vector2);
vector2.normalize();
// referenceVector.cross(referenceVector, principalRotationVector);
vector2.cross(vector1, vector2);
vector2.normalize();
if (ref.dot(vector2) < 0) {
vector2.negate();
}
// System.out.println("Mod. refVector: " + vector2);
return vector2;
}
/**
* Returns the default reference vector for the alignment of Cn structures
* @return
*/
private Vector3d getReferenceAxisCylic() {
if ("C2".equals(rotationGroup.getPointGroup())) {
Vector3d vr = new Vector3d(subunits.getOriginalCenters().get(0));
vr.sub(subunits.getCentroid());
vr.normalize();
return vr;
}
// get principal axis vector that is perpendicular to the principal
// rotation vector
Vector3d vmin = null;
double dotMin = 1.0;
for (Vector3d v: principalAxesOfInertia) {
if (Math.abs(principalRotationVector.dot(v)) < dotMin) {
dotMin = Math.abs(principalRotationVector.dot(v));
vmin = new Vector3d(v);
}
}
if (principalRotationVector.dot(vmin) < 0) {
vmin.negate();
}
return vmin;
}
/**
* Returns a reference vector for the alignment of Cn structures.
* @return reference vector
*/
private Vector3d getReferenceAxisCylicWithSubunitAlignment() {
if ("C2".equals(rotationGroup.getPointGroup())) {
return referenceVector;
}
// find subunit that extends the most in the xy-plane
List> orbits = getOrbitsByXYWidth();
// get the last orbit which is the widest
List widestOrbit = orbits.get(orbits.size()-1);
List centers = subunits.getCenters();
int subunit = widestOrbit.get(0);
// calculate reference vector
Vector3d refAxis = new Vector3d();
refAxis.sub(centers.get(subunit), subunits.getCentroid());
refAxis.normalize();
return refAxis;
}
/**
*
*/
private Vector3d getReferenceAxisDihedralWithSubunitAlignment() {
int maxFold = rotationGroup.getRotation(0).getFold();
double minAngle = Double.MAX_VALUE;
Vector3d refVec = null;
Vector3d ref = getSubunitReferenceVector();
for (int i = 0; i < rotationGroup.getOrder(); i++) {
if (rotationGroup.getRotation(i).getDirection() == 1 &&
(rotationGroup.getRotation(i).getFold() < maxFold) ||
"D2".equals(rotationGroup.getPointGroup())) {
AxisAngle4d axisAngle = rotationGroup.getRotation(i).getAxisAngle();
Vector3d v = new Vector3d(axisAngle.x, axisAngle.y, axisAngle.z);
v.normalize();
// System.out.println("Ref axis angle(+): " + Math.toDegrees(v.angle(ref)));
double angle = v.angle(ref);
if (angle < minAngle) {
minAngle = angle;
refVec = v;
}
Vector3d vn = new Vector3d(v);
vn.negate();
// System.out.println("Ref axis angle(-): " + Math.toDegrees(vn.angle(ref)));
angle = vn.angle(ref);
if (angle < minAngle) {
minAngle = angle;
refVec = vn;
}
}
}
refVec.normalize();
return refVec;
}
/**
*
*/
private Vector3d getReferenceAxisDihedral() {
int maxFold = rotationGroup.getRotation(0).getFold();
// one exception: D2
if (maxFold == 2) {
maxFold = 3;
}
// TODO how about D2, where minor axis = 2 = principal axis??
for (int i = 0; i < rotationGroup.getOrder(); i++) {
if (rotationGroup.getRotation(i).getDirection() == 1 && rotationGroup.getRotation(i).getFold() < maxFold) {
AxisAngle4d axisAngle = rotationGroup.getRotation(i).getAxisAngle();
Vector3d v = new Vector3d(axisAngle.x, axisAngle.y, axisAngle.z);
v.normalize();
return v;
}
}
return null;
}
private Vector3d getReferenceAxisTetrahedral() {
for (int i = 0; i < rotationGroup.getOrder(); i++) {
AxisAngle4d axisAngle = rotationGroup.getRotation(i).getAxisAngle();
Vector3d v = new Vector3d(axisAngle.x, axisAngle.y, axisAngle.z);
double d = v.dot(principalRotationVector);
if (rotationGroup.getRotation(i).getFold() == 3) {
// the dot product 0 is between to adjacent 3-fold axes
if (d > 0.3 && d < 0.9) {
return v;
}
}
}
return null;
}
private Vector3d getReferenceAxisOctahedral() {
for (int i = 0; i < rotationGroup.getOrder(); i++) {
AxisAngle4d axisAngle = rotationGroup.getRotation(i).getAxisAngle();
Vector3d v = new Vector3d(axisAngle.x, axisAngle.y, axisAngle.z);
double d = v.dot(principalRotationVector);
if (rotationGroup.getRotation(i).getFold() == 4) {
// the dot product 0 is between to adjacent 4-fold axes
if (d > -0.1 && d < 0.1 ) {
return v;
}
}
}
return null;
}
private Vector3d getReferenceAxisIcosahedral() {
for (int i = 0; i < rotationGroup.getOrder(); i++) {
AxisAngle4d axisAngle = rotationGroup.getRotation(i).getAxisAngle();
Vector3d v = new Vector3d(axisAngle.x, axisAngle.y, axisAngle.z);
double d = v.dot(principalRotationVector);
if (rotationGroup.getRotation(i).getFold() == 5) {
// the dot product of 0.447.. is between to adjacent 5-fold axes
// if (d > 0.447 && d < 0.448) {
if (d > 0.4 && d < 0.5) {
return v;
}
}
}
return null;
}
private Vector3d getSubunitReferenceVector() {
int n = subunits.getSubunitCount();
Point3d probe = new Point3d();
// transform subunit centers into z-aligned position and calculate
// width in xy direction.
double maxWidthSq = 0;
Point3d ref = null;
for (int i = 0; i < n; i++) {
for (Point3d p: subunits.getTraces().get(i)) {
probe.set(p);
transformationMatrix.transform(probe);
double widthSq = probe.x*probe.x + probe.y*probe.y;
if (widthSq > maxWidthSq) {
maxWidthSq = widthSq;
ref = p;
}
}
}
// System.out.println("width: " + maxWidthSq);
Vector3d refVector = new Vector3d();
refVector.sub(ref, subunits.getCentroid());
refVector.normalize();
return refVector;
}
private static Matrix4d flipX() {
Matrix4d rot = new Matrix4d();
rot.m00 = 1;
rot.m11 = -1;
rot.m22 = -1;
rot.m33 = 1;
return rot;
}
private static Matrix4d flipY() {
Matrix4d rot = new Matrix4d();
rot.m00 = -1;
rot.m11 = 1;
rot.m22 = -1;
rot.m33 = 1;
return rot;
}
private static Matrix4d flipZ() {
Matrix4d rot = new Matrix4d();
rot.m00 = -1;
rot.m11 = -1;
rot.m22 = 1;
rot.m33 = 1;
return rot;
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy