Package uk.ac.starlink.ttools.func
Class Maths
java.lang.Object
uk.ac.starlink.ttools.func.Maths
Standard mathematical and trigonometric functions.
Trigonometric functions work with angles in radians.
- Since:
- 2 Sep 2004
- Author:
- Mark Taylor (Starlink)
-
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final double
Euler's number e, the base of natural logarithms.static final double
Positive infinite floating point value.static final double
Not-a-Number floating point value.static final double
Pi, the ratio of the circumference of a circle to its diameter. -
Method Summary
Modifier and TypeMethodDescriptionstatic double
acos
(double x) Arc cosine of an angle.static double
acosh
(double x) Inverse hyperbolic cosine.static double
asin
(double x) Arc sine of an angle.static double
asinh
(double x) Inverse hyperbolic sine.static double
atan
(double x) Arc tangent of an angle.static double
atan2
(double y, double x) Converts rectangular coordinates (x
,y
) to polar (r
,theta
).static double
atanh
(double x) Inverse hyperbolic tangent.static double
cos
(double theta) Cosine of an angle.static double
cosh
(double x) Hyperbolic cosine.static double
exp
(double x) Euler's number e raised to a power.static double
exp10
(double x) Power of 10.static double
hypot
(double... xs) Returns the square root of the sum of squares of its arguments.static double
ln
(double x) Natural logarithm.static double
log10
(double x) Logarithm to base 10.static double
pow
(double a, double b) Exponentiation.static double
sin
(double theta) Sine of an angle.static double
sinh
(double x) Hyperbolic sine.static double
sqrt
(double x) Square root.static double
square
(double x) Raise to the power 2.static double
tan
(double theta) Tangent of an angle.static double
tanh
(double x) Hyperbolic tangent.
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Field Details
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E
public static final double EEuler's number e, the base of natural logarithms.- See Also:
-
PI
public static final double PIPi, the ratio of the circumference of a circle to its diameter.- See Also:
-
Infinity
public static final double InfinityPositive infinite floating point value.- See Also:
-
NaN
public static final double NaNNot-a-Number floating point value. Use with care; arithmetic and logical operations behave in strange ways near NaN (for instance,NaN!=NaN
). For most purposes this is equivalent to the blank value.- See Also:
-
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Method Details
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sin
public static double sin(double theta) Sine of an angle.- Parameters:
theta
- an angle, in radians.- Returns:
- the sine of the argument.
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cos
public static double cos(double theta) Cosine of an angle.- Parameters:
theta
- an angle, in radians.- Returns:
- the cosine of the argument.
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tan
public static double tan(double theta) Tangent of an angle.- Parameters:
theta
- an angle, in radians.- Returns:
- the tangent of the argument.
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asin
public static double asin(double x) Arc sine of an angle. The result is in the range of -pi/2 through pi/2.- Parameters:
x
- the value whose arc sine is to be returned.- Returns:
- the arc sine of the argument (radians)
-
acos
public static double acos(double x) Arc cosine of an angle. The result is in the range of 0.0 through pi.- Parameters:
x
- the value whose arc cosine is to be returned.- Returns:
- the arc cosine of the argument (radians)
-
atan
public static double atan(double x) Arc tangent of an angle. The result is in the range of -pi/2 through pi/2.- Parameters:
x
- the value whose arc tangent is to be returned.- Returns:
- the arc tangent of the argument (radians)
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ln
public static double ln(double x) Natural logarithm.- Parameters:
x
- argument- Returns:
- loge(x)
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exp
public static double exp(double x) Euler's number e raised to a power.- Parameters:
x
- the exponent to raise e to.- Returns:
- the value ex, where e is the base of the natural logarithms.
-
log10
public static double log10(double x) Logarithm to base 10.- Parameters:
x
- argument- Returns:
- log10(x)
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exp10
public static double exp10(double x) Power of 10. This convenience function is identical topow(10,x)
.- Parameters:
x
- argument- Returns:
- 10x
-
sqrt
public static double sqrt(double x) Square root. The result is correctly rounded and positive.- Parameters:
x
- a value.- Returns:
- the positive square root of
x
. If the argument is NaN or less than zero, the result is NaN.
-
square
public static double square(double x) Raise to the power 2.- Parameters:
x
- a value- Returns:
- x * x
-
hypot
public static double hypot(double... xs) Returns the square root of the sum of squares of its arguments. In the 2-argument case, doing it like this may avoid intermediate overflow or underflow.- Parameters:
xs
- one or more numeric values- Returns:
- sqare root of sum of squares of arguments
- Examples:
hypot(3,4) = 5
,hypot(2,2,2,2) = 4
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atan2
public static double atan2(double y, double x) Converts rectangular coordinates (x
,y
) to polar (r
,theta
). This method computes the phasetheta
by computing an arc tangent ofy/x
in the range of -pi to pi.- Parameters:
y
- the ordinate coordinatex
- the abscissa coordinate- Returns:
- the
theta
component (radians) of the point (r
,theta
) in polar coordinates that corresponds to the point (x
,y
) in Cartesian coordinates.
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pow
public static double pow(double a, double b) Exponentiation. The result is the value of the first argument raised to the power of the second argument.- Parameters:
a
- the base.b
- the exponent.- Returns:
- the value
ab
.
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sinh
public static double sinh(double x) Hyperbolic sine.- Parameters:
x
- parameter- Returns:
- result
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cosh
public static double cosh(double x) Hyperbolic cosine.- Parameters:
x
- parameter- Returns:
- result
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tanh
public static double tanh(double x) Hyperbolic tangent.- Parameters:
x
- parameter- Returns:
- result
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asinh
public static double asinh(double x) Inverse hyperbolic sine.- Parameters:
x
- parameter- Returns:
- result
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acosh
public static double acosh(double x) Inverse hyperbolic cosine.- Parameters:
x
- parameter- Returns:
- result
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atanh
public static double atanh(double x) Inverse hyperbolic tangent.- Parameters:
x
- parameter- Returns:
- result
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