Package ffx.numerics.math

Class FloatMath

java.lang.Object

ffx.numerics.math.FloatMath

public class FloatMath
extends Object

The FloatMath class is a simple math library that operates on 3-coordinate float arrays.

All methods are static and thread-safe.

Use instances of Float3 for convenience.

Since:

1.0

Author:

Michael J. Schnieders

Method Summary

Modifier and Type	Method	Description
static float[]	add(float[] a, float[] b)	sum
static float[]	add(float[] a, float[] b, float[] ret)	sum
static float	angle(float[] i, float[] j)	angle
static float	bondAngle(float[] i, float[] j, float[] k)	Finds the angle formed by three atoms
static float	dihedralAngle(float[] a, float[] b, float[] c, float[] d)	Finds the dihedral angle formed between 4 atoms
static float	dist(float[] a, float[] b)	Finds the distance between two vectors.
static float	dist2(float[] a, float[] b)	Finds the squared distance between two vectors.
static float	dot(float[] a, float[] b)	Finds the dot product between two vectors.
static float[]	fma(float[] a, float b, float[] c)	Compute a * b + c and return the result in a new array.
static float[]	fma(float[] a, float b, float[] c, float[] ret)	Compute a * b + c.
static float	length(float[] d)	Finds the length of a vector.
static float	length2(float[] d)	Finds the length of a vector squared.
static void	log(float[] v)	logVector
static void	log(float[] v, String label)	logVector.
static float[]	normalize(float[] n)	Normalizes a vector.
static float[]	normalize(float[] n, float[] ret)	Normalizes a vector.
static float[]	scale(float[] n, float a)	Scales a vector.
static float[]	scale(float[] n, float a, float[] ret)	Scales a vector.
static float[]	square(float[] n)	Squares values of a vector.
static float[]	square(float[] n, float[] ret)	Squares values of a vector.
static float[]	squareRoot(float[] n)	Square root values of a vector.
static float[]	squareRoot(float[] n, float[] ret)	Square root values of a vector.
static float[]	sub(float[] a, float[] b)	Finds the difference between two vectors.
static float[]	sub(float[] a, float[] b, float[] ret)	Finds the difference between two vectors
static String	toString(float[] v)	logVector.
static String	toString(float[] v, String label)	vectorToString.
static float[]	X(float[] a, float[] b)	Finds the cross-product between two vectors.
static float[]	X(float[] a, float[] b, float[] ret)	Finds the cross-product between two vectors.

Methods inherited from class java.lang.Object

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

Method Details

fma

public static float[] fma(float[] a,
 float b,
 float[] c)

Compute a * b + c and return the result in a new array.

Parameters:

a - First vector.

b - Scalar.

c - Second vector.

Returns:

Returns a * b + c.

fma

public static float[] fma(float[] a,
 float b,
 float[] c,
 float[] ret)

Compute a * b + c.

Parameters:

a - First vector.

b - Scalar.

c - Second vector.

ret - Result vector.

Returns:

Returns a * b + c in the vector ret.

X

public static float[] X(float[] a,
 float[] b)

Finds the cross-product between two vectors.

Parameters:

a - First vector.

b - Second vector.

Returns:

Returns the cross-product.

X

public static float[] X(float[] a,
 float[] b,
 float[] ret)

Finds the cross-product between two vectors.

Parameters:

a - First vector.

b - Second vector.

ret - The cross-product of a x b.

Returns:

Returns the cross-product ret.

add

public static float[] add(float[] a,
 float[] b)

sum

Parameters:

a - an array of float.

b - an array of float.

Returns:

Returns the array ret.

add

public static float[] add(float[] a,
 float[] b,
 float[] ret)

sum

Parameters:

a - an array of float.

b - an array of float.

ret - an array of float.

Returns:

Returns the array ret.

angle

public static float angle(float[] i,
 float[] j)

angle

Parameters:

i - an array of float.

j - an array of float.

Returns:

Returns the angle.

bondAngle

public static float bondAngle(float[] i,
 float[] j,
 float[] k)

Finds the angle formed by three atoms

Parameters:

i - Atom position vector.

j - Atom position vector (central atom).

k - Atom position vector.

Returns:

Returns the angle in the range [ -pi, pi ].

dihedralAngle

public static float dihedralAngle(float[] a,
 float[] b,
 float[] c,
 float[] d)

Finds the dihedral angle formed between 4 atoms

Parameters:

a - Atom position vector.

b - Atom position vector.

c - Atom position vector.

d - Atom position vector.

Returns:

The dihedral angle in the range [ -pi, pi ].

dist

public static float dist(float[] a,
 float[] b)

Finds the distance between two vectors.

Parameters:

a - First vector.

b - Second vector.

Returns:

Returns the distance between vectors a and b.

dist2

public static float dist2(float[] a,
 float[] b)

Finds the squared distance between two vectors.

Parameters:

a - First vector.

b - Second vector.

Returns:

Returns the squared distance between vectors a and b.

dot

public static float dot(float[] a,
 float[] b)

Finds the dot product between two vectors.

Parameters:

a - First vector.

b - Second vector.

Returns:

Returns the dot product of a and b.

length

public static float length(float[] d)

Finds the length of a vector.

Parameters:

d - A vector to find the length of.

Returns:

Returns the length of vector d.

length2

public static float length2(float[] d)

Finds the length of a vector squared.

Parameters:

d - A vector to find the length of squared.

Returns:

Returns the length of vector d squared.

log

public static void log(float[] v)

logVector

Parameters:

v - an array of float.

log

public static void log(float[] v,
 String label)

logVector.

Parameters:

v - an array of

invalid reference

float

objects.

label - a String object.

normalize

public static float[] normalize(float[] n)

Normalizes a vector.

Parameters:

n - A vector to be normalized.

Returns:

Returns the normalized vector.

normalize

public static float[] normalize(float[] n,
 float[] ret)

Normalizes a vector.

Parameters:

n - A vector to be normalized.

ret - The normalized vector.

Returns:

Returns the normalized vector.

scale

public static float[] scale(float[] n,
 float a)

Scales a vector.

Parameters:

n - A vector to be scaled.

a - A scalar value.

Returns:

Returns the scaled vector.

scale

public static float[] scale(float[] n,
 float a,
 float[] ret)

Scales a vector.

Parameters:

n - A vector to be scaled.

a - A scalar value.

ret - The scaled Vector.

Returns:

Returns the array ret.

square

public static float[] square(float[] n)

Squares values of a vector.

Parameters:

n - A vector to be squared.

Returns:

Returns the squared vector.

square

public static float[] square(float[] n,
 float[] ret)

Squares values of a vector.

Parameters:

n - A vector to be squared.

ret - The squared vector.

Returns:

Returns the array ret.

squareRoot

public static float[] squareRoot(float[] n)

Square root values of a vector.

Parameters:

n - A vector to determine square root.

Returns:

Returns the rooted vector.

squareRoot

public static float[] squareRoot(float[] n,
 float[] ret)

Square root values of a vector.

Parameters:

n - A vector to determine square root.

ret - The rooted vector.

Returns:

Returns the array ret.

sub

public static float[] sub(float[] a,
 float[] b)

Finds the difference between two vectors.

Parameters:

a - First vector

b - Second vector

Returns:

Returns the difference ret.

sub

public static float[] sub(float[] a,
 float[] b,
 float[] ret)

Finds the difference between two vectors

Parameters:

a - First vector

b - Second vector

ret - Return Values

Returns:

Returns the difference ret.

toString

public static String toString(float[] v)

logVector.

Parameters:

v - an array of float.

Returns:

Returns a String description of the vector.

toString

public static String toString(@Nullable
 float[] v,
 @Nullable
 String label)

vectorToString.

Parameters:

v - an array of

invalid reference

float

objects.

label - a String object.

Returns:

Returns a String description of the vector.