org.biojava.bio.structure
Class Calc

java.lang.Object
  org.biojava.bio.structure.Calc

public class Calc
extends Object

utility operations on Atoms, AminoAcids, etc.

Currently the coordinates of an Atom are stored as an array of size 3 (double[3]). It would be more powerful to use Point3D from javax.vecmath. but unfortunately this is not a part of standard java installations, since it comes with java3d . So to keep things simple at the moment biojava does not depend on java3d.

Since:

1.4

Version:

%I% %G%

Author:

Andreas Prlic

Field Summary

static float	degreesPerRadian Degrees per radian.
static float	radiansPerDegree Radians per degree.

Constructor Summary

Calc()

Method Summary

static Atom	add(Atom a, Atom b) add two atoms ( a + b).
static double	amount(Atom a) amount.
static double	angle(Atom a, Atom b) angle.
static Atom[]	centerAtoms(Atom[] atomSet) Center the atoms at the Centroid.
static Atom[]	centerAtoms(Atom[] atomSet, Atom centroid) Center the atoms at the Centroid, if the centroid is already know.
static Atom	centerOfMass(Atom[] points)
static Atom	createVirtualCBAtom(AminoAcid amino) creates a virtual C-beta atom.
static Atom	getCenterVector(Atom[] atomSet) Returns the Vector that needs to be applied to shift a set of atoms to the Centroid.
static Atom	getCenterVector(Atom[] atomSet, Atom centroid) Returns the Vector that needs to be applied to shift a set of atoms to the Centroid, if the centroid is already known
static Atom	getCentroid(Atom[] atomSet) Returns the center of mass of the set of atoms.
static double	getDistance(Atom a, Atom b) calculate distance between two atoms.
static double	getDistanceFast(Atom a, Atom b) Will calculate the *square* of distances between two atoms.
static double	getPhi(AminoAcid a, AminoAcid b) phi angle.
static double	getPsi(AminoAcid a, AminoAcid b) psi angle.
static double[]	getXYZEuler(Matrix m) Convert a rotation Matrix to Euler angles.
static double[]	getZYZEuler(Matrix m) Gget euler angles for a matrix given in ZYZ convention.
static Atom	invert(Atom a)
static boolean	isConnected(AminoAcid a, AminoAcid b) test if two amino acids are connected, i.e.
static Matrix	matrixFromEuler(double heading, double attitude, double bank) This conversion uses NASA standard aeroplane conventions as described on page: http://www.euclideanspace.com/maths/geometry/rotations/euler/index.htm Coordinate System: right hand Positive angle: right hand Order of euler angles: heading first, then attitude, then bank.
static void	plus(Structure s, Matrix matrix) calculate structure + Matrix coodinates ...
static void	rotate(Atom atom, double[][] m) rotate a single atom aroud a rotation matrix.
static void	rotate(Atom atom, Matrix m) Rotate an atom around a Matrix object.
static void	rotate(Group group, double[][] rotationmatrix) rotate a structure .
static void	rotate(Group group, Matrix m) Rotate a group object.
static void	rotate(Structure structure, double[][] rotationmatrix) Rotate a structure.
static void	rotate(Structure structure, Matrix m) Rotate a structure object.
static Atom	scaleAdd(float s, Atom t1, Atom t2)
static void	shift(Atom a, Atom b) Shift a vector.
static void	shift(Group group, Atom a) Shift a Group with a vector.
static void	shift(Structure structure, Atom a) shift a structure with a vector.
static double	skalarProduct(Atom a, Atom b) skalar product.
static Atom	substract(Atom a, Atom b) Deprecated. use subtract instead.
static Atom	subtract(Atom a, Atom b) subtract two atoms ( a - b).
static double	torsionAngle(Atom a, Atom b, Atom c, Atom d) torsion angle = angle between the normal vectors of the two plains a-b-c and b-c-d.
static Atom	unitVector(Atom a) return the unit vector of vector a .
static Atom	vectorProduct(Atom a, Atom b) Vector product .

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

radiansPerDegree

public static final float radiansPerDegree

Radians per degree.

See Also:

Constant Field Values

degreesPerRadian

public static final float degreesPerRadian

Degrees per radian.

See Also:

Constant Field Values

Constructor Detail

Calc

public Calc()

Method Detail

getDistance

public static final double getDistance(Atom a,
                                       Atom b)
                                throws StructureException

calculate distance between two atoms.

Parameters:

a - an Atom object

b - an Atom object

Returns:

a double

Throws:

StructureException - ...

getDistanceFast

public static double getDistanceFast(Atom a,
                                     Atom b)
                              throws StructureException

Will calculate the *square* of distances between two atoms. This will be faster as it will not perform the final square root to get the actual distance. Use this if doing large numbers of distance comparisons - it is marginally faster than getDistance().

Parameters:

a - an Atom object

b - an Atom object

Returns:

a double

Throws:

StructureException - ...

invert

public static final Atom invert(Atom a)
                         throws StructureException

Throws:

StructureException

add

public static final Atom add(Atom a,
                             Atom b)

add two atoms ( a + b).

Parameters:

a - an Atom object

b - an Atom object

Returns:

an Atom object

substract

public static final Atom substract(Atom a,
                                   Atom b)
                            throws StructureException

Deprecated. use subtract instead.

subtract two atoms ( a - b).

Parameters:

a - an Atom object

b - an Atom object

Returns:

an Atom object

Throws:

StructureException - ...

subtract

public static final Atom subtract(Atom a,
                                  Atom b)
                           throws StructureException

subtract two atoms ( a - b).

Parameters:

a - an Atom object

b - an Atom object

Returns:

an Atom object

Throws:

StructureException - ...

vectorProduct

public static final Atom vectorProduct(Atom a,
                                       Atom b)

Vector product .

Parameters:

a - an Atom object

b - an Atom object

Returns:

an Atom object

skalarProduct

public static final double skalarProduct(Atom a,
                                         Atom b)

skalar product.

Parameters:

a - an Atom object

b - an Atom object

Returns:

a double

amount

public static final double amount(Atom a)

amount.

Parameters:

a - an Atom object

Returns:

a double

angle

public static final double angle(Atom a,
                                 Atom b)

angle.

Parameters:

a - an Atom object

b - an Atom object

Returns:

a double

unitVector

public static final Atom unitVector(Atom a)

return the unit vector of vector a .

Parameters:

a - an Atom object

Returns:

an Atom object

torsionAngle

public static final double torsionAngle(Atom a,
                                        Atom b,
                                        Atom c,
                                        Atom d)
                                 throws StructureException

torsion angle = angle between the normal vectors of the two plains a-b-c and b-c-d.

Parameters:

a - an Atom object

b - an Atom object

c - an Atom object

d - an Atom object

Returns:

a double

Throws:

StructureException - ...

getPhi

public static final double getPhi(AminoAcid a,
                                  AminoAcid b)
                           throws StructureException

phi angle.

Parameters:

a - an AminoAcid object

b - an AminoAcid object

Returns:

a double

Throws:

StructureException - ...

getPsi

public static final double getPsi(AminoAcid a,
                                  AminoAcid b)
                           throws StructureException

psi angle.

Parameters:

a - an AminoAcid object

b - an AminoAcid object

Returns:

a double

Throws:

StructureException - ...

isConnected

public static final boolean isConnected(AminoAcid a,
                                        AminoAcid b)
                                 throws StructureException

test if two amino acids are connected, i.e. if the distance from C to N < 2,5 Angstrom.

Parameters:

a - an AminoAcid object

b - an AminoAcid object

Returns:

true if ...

Throws:

StructureException - ...

rotate

public static final void rotate(Atom atom,
                                double[][] m)

rotate a single atom aroud a rotation matrix. matrix must be a 3x3 matrix.

Parameters:

atom - atom to be rotated

m - a rotation matrix represented as a double[3][3] array

rotate

public static final void rotate(Structure structure,
                                double[][] rotationmatrix)
                         throws StructureException

Rotate a structure.

Parameters:

structure - a Structure object

rotationmatrix - an array (3x3) of double representing the rotation matrix.

Throws:

StructureException - ...

rotate

public static final void rotate(Group group,
                                double[][] rotationmatrix)
                         throws StructureException

rotate a structure .

Parameters:

group - a group object

rotationmatrix - an array (3x3) of double representing the rotation matrix.

Throws:

StructureException - ...

rotate

public static final void rotate(Atom atom,
                                Matrix m)

Rotate an atom around a Matrix object.

Parameters:

atom - atom to be rotated

m - rotation matrix to be applied to the atom

rotate

public static final void rotate(Group group,
                                Matrix m)

Rotate a group object.

Parameters:

group - a group to be rotated

m - a Matrix object representing the translation matrix

rotate

public static final void rotate(Structure structure,
                                Matrix m)

Rotate a structure object.

Parameters:

structure - the structure to be rotated

m - rotation matrix to be applied

plus

public static final void plus(Structure s,
                              Matrix matrix)

calculate structure + Matrix coodinates ...

Parameters:

s - the structure to operate on

matrix - a Matrix object

shift

public static final void shift(Structure structure,
                               Atom a)

shift a structure with a vector.

Parameters:

structure - a Structure object

a - an Atom object representing a shift vector

shift

public static final void shift(Atom a,
                               Atom b)

Shift a vector.

Parameters:

a - vector a

b - vector b

shift

public static final void shift(Group group,
                               Atom a)

Shift a Group with a vector.

Parameters:

group - a group object

a - an Atom object representing a shift vector

getCentroid

public static final Atom getCentroid(Atom[] atomSet)

Returns the center of mass of the set of atoms.

Parameters:

atomSet - a set of Atoms

Returns:

an Atom representing the Centroid of the set of atoms

centerOfMass

public static Atom centerOfMass(Atom[] points)

scaleAdd

public static Atom scaleAdd(float s,
                            Atom t1,
                            Atom t2)

getCenterVector

public static final Atom getCenterVector(Atom[] atomSet)

Returns the Vector that needs to be applied to shift a set of atoms to the Centroid.

Parameters:

atomSet - array of Atoms

Returns:

the vector needed to shift the set of atoms to its geometric center

getCenterVector

public static final Atom getCenterVector(Atom[] atomSet,
                                         Atom centroid)

Returns the Vector that needs to be applied to shift a set of atoms to the Centroid, if the centroid is already known

Parameters:

atomSet - array of Atoms

Returns:

the vector needed to shift the set of atoms to its geometric center

centerAtoms

public static final Atom[] centerAtoms(Atom[] atomSet)
                                throws StructureException

Center the atoms at the Centroid.

Parameters:

atomSet - a set of Atoms

Returns:

an Atom representing the Centroid of the set of atoms

Throws:

StructureException

centerAtoms

public static final Atom[] centerAtoms(Atom[] atomSet,
                                       Atom centroid)
                                throws StructureException

Center the atoms at the Centroid, if the centroid is already know.

Parameters:

atomSet - a set of Atoms

Returns:

an Atom representing the Centroid of the set of atoms

Throws:

StructureException

createVirtualCBAtom

public static final Atom createVirtualCBAtom(AminoAcid amino)
                                      throws StructureException

creates a virtual C-beta atom. this might be needed when working with GLY thanks to Peter Lackner for a python template of this method.

Parameters:

amino - the amino acid for which a "virtual" CB atom should be calculated

Returns:

a "virtual" CB atom

Throws:

StructureException

getZYZEuler

public static final double[] getZYZEuler(Matrix m)

Gget euler angles for a matrix given in ZYZ convention. (as e.g. used by Jmol)

Parameters:

m - the rotation matrix

Returns:

the euler values for a rotation around Z, Y, Z in degrees...

getXYZEuler

public static final double[] getXYZEuler(Matrix m)

Convert a rotation Matrix to Euler angles. This conversion uses conventions as described on page: http://www.euclideanspace.com/maths/geometry/rotations/euler/index.htm Coordinate System: right hand Positive angle: right hand Order of euler angles: heading first, then attitude, then bank

Parameters:

m - the rotation matrix

Returns:

a array of three doubles containing the three euler angles in radians

matrixFromEuler

public static final Matrix matrixFromEuler(double heading,
                                           double attitude,
                                           double bank)

This conversion uses NASA standard aeroplane conventions as described on page: http://www.euclideanspace.com/maths/geometry/rotations/euler/index.htm Coordinate System: right hand Positive angle: right hand Order of euler angles: heading first, then attitude, then bank. matrix row column ordering: [m00 m01 m02] [m10 m11 m12] [m20 m21 m22]

Parameters:

heading - in radians

attitude - in radians

bank - in radians

Returns:

the rotation matrix