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

Constructor Summary

Constructors

Constructor	Description
FloatMath()

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

Constructor Details

FloatMath

public FloatMath()

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.