math Class Reference

#include <LUA_API_Math.h>

Public Member Functions
	abs ()
	The Math abs function always returns the non-negative number, of a given value. More...
	acos ()
	The Math acos function returns the inverse cosine of the given value. More...
	asin ()
	The Math asin function returns the inverse sine of the given value. More...
	atan ()
	Return the inverse tangent. We can do this by supplying y/x ourselves using math.atan() or we can pass y and x to atan2() to do this for us. The following is a Small Example on how to use this function: More...
	atan2 ()
	Return the inverse tangent. We can do this by supplying y/x ourselves using math.atan() or we can pass y and x to atan2() to do this for us. The following is a Small Example on how to use this function: More...
	ceil ()
	The Math ceil function returns the integer no greater than or no less than the given value. More...
	floor ()
	The Math floor function returns the integer no greater than or no less than the given value. More...
	cos ()
	The Math cos function returns the cosine number for a given value in radians. More...
	sin ()
	The Math sin function returns the cosine number for a given value in radians. More...
	tan ()
	The Math tan function returns the cosine number for a given value in radians. More...
	cosh ()
	The Math cosh function returns the hyperbolic cosine number for a given value. More...
	sinh ()
	The Math cosh function returns the hyperbolic sine number for a given value. More...
	tanh ()
	The Math cosh function returns the hyperbolic tangent[2] number for a given value. More...
	deg ()
	The Math deg function allows you to convert from radians to degrees. More...
	rad ()
	The Math deg function allows you to convert from degrees to radians. More...
	exp ()
	math.exp(myval) returns e (the base of natural logarithms) raised to the power myval. More...
	log ()
	math.log() returns the inverse of math.exp(). math.exp(1) returns e. More...
	log10 ()
	The Math abs function returns the base 10 logarithm of a given number. The number must be positive. More...
	frexp ()
	This is a normalisation function [6]. The math.frexp() function is used to split the number value into a normalized fraction and an exponent. Two values are returned: the first is a value always in the range 1/2 (inclusive) to 1 (exclusive) and the second is an exponent.The number value will be returned in the operation: More...
	ldexp ()
	The math.ldexp() function takes a normalised number and returns the floating point representation. This is the value multiplied by 2 to the power of the exponent, i.e.: More...
	huge ()
	math.huge is a constant. It represents +infinity. More...
	max ()
	The Math max function returns the maximum value from a variable length list of arguments. More...
	min ()
	The Math min function returns the minimum value from a variable length list of arguments. More...
	modf ()
	The Math abs function always returns the non-negative number, of a given value. More...
	pi ()
	This is the constant PI. More...
	pow ()
	math.pow() raises the first parameter to the power of the second parameter and returns the result. The binary ^ operator performs the same job as math.pow(), i.e. math.pow(x,y) == x^y. More...
	random ()
	math.random() generates pseudo-random numbers uniformly distributed. Supplying argument alters its behaviour: More...
	randomseed ()
	The math.randomseed() function sets a seed for the pseudo-random generator: Equal seeds produce equal sequences of numbers. More...
	sqrt ()
	The Math sqrt function returns the square root of a given number. Only non-negative arguments are allowed. More...
skyMath	linearInterp (inputValue, scaleRangeMin, scaleRangeMax, minOut, maxOut)
	skyMath.linearInterp(inputValue, scaleRangeMin, scaleRangeMax, minOut, maxOut ); More...

Detailed Description

When Working with the Lua Language you will encounter the need to use the math library. For the Purpose of scripting in skyline, we have included a copy of the math library API

Math Functions are accessed by calling math.function().

Member Function Documentation

math::abs

(

)

The Math abs function always returns the non-negative number, of a given value.

The following is a Small Example on how to use this function:

math.abs(-100)  : returns 100
math.abs(25.67) : returns 25.67
math.abs(0)     : returns 0

math::acos

(

)

The Math acos function returns the inverse cosine of the given value.

The following is a Small Example on how to use this function:

math.acos(1) : returns 0
math.acos(0) : returns 1.5707963267949

math::asin

(

)

The Math asin function returns the inverse sine of the given value.

The following is a Small Example on how to use this function:

math.asin(1) : returns 1.5707963267949
math.asin(0) : returns 0

math::atan

(

)

Return the inverse tangent. We can do this by supplying y/x ourselves using math.atan() or we can pass y and x to atan2() to do this for us.
The following is a Small Example on how to use this function:

c, s = math.cos(0.8), math.sin(0.8)
math.atan(s/c) : returns 0.8

math::atan2

(

)

Return the inverse tangent. We can do this by supplying y/x ourselves using math.atan() or we can pass y and x to atan2() to do this for us.
The following is a Small Example on how to use this function:

c, s = math.cos(0.8), math.sin(0.8)
math.atan2(s,c) : returns 0.8

math::ceil

(

)

The Math ceil function returns the integer no greater than or no less than the given value.

The following is a Small Example on how to use this function:

math.ceil(0.5) : returns 1

math::cos

(

)

The Math cos function returns the cosine number for a given value in radians.

The following is a Small Example on how to use this function:

math.cos(math.pi / 4) : returns 0.70710678118655

math::cosh

(

)

The Math cosh function returns the hyperbolic cosine number for a given value.

The following is a Small Example on how to use this function:

math.cosh(1) : returns 1.5430806348152

math::deg

(

)

The Math deg function allows you to convert from radians to degrees.

The following is a Small Example on how to use this function:

math.deg(math.pi)      : returns 180
math.deg(math.pi / 2)  : returns 90

math::exp

(

)

math.exp(myval) returns e (the base of natural logarithms) raised to the power myval.

The following is a Small Example on how to use this function:

math.exp(0) : returns 1
math.exp(1) : returns 2.718281828459
math.exp(27) : returns 532048240601.8

math::floor

(

)

The Math floor function returns the integer no greater than or no less than the given value.

The following is a Small Example on how to use this function:

math.floor(0.5) : returns 0

math::frexp

(

)

This is a normalisation function [6]. The math.frexp() function is used to split the number value into a normalized fraction and an exponent.
Two values are returned: the first is a value always in the range 1/2 (inclusive) to 1 (exclusive) and the second is an exponent.The number value will be
returned in the operation:

normalized_fraction * 2 ^ exponent

The following is a Small Example on how to use this function:

math.frexp(2) : returns 0.5     2
math.frexp(3) : returns 0.75    2
math.frexp(128) : returns 0.5     8
math.frexp(3.1415927) : returns 0.785398175     2

math::huge

(

)

math.huge is a constant. It represents +infinity.

The following is a Small Example on how to use this function:

math.huge : returns inf
math.huge / 2 : returns inf

-math.huge : returns -inf

math.huge/math.huge : returns nan -- indeterminate  
math.huge * 0 : returns nan -- indeterminate

1/0 : returns inf

(math.huge == math.huge) : returns true

(1/0 == math.huge) : returns true

math::ldexp

(

)

The math.ldexp() function takes a normalised number and returns the floating point representation. This is the value multiplied by 2 to the power of the exponent, i.e.:

The following is a Small Example on how to use this function:

math.ldexp(x, exp) == x * 2 ^ exp : returns true

math.ldexp(0.785,2) : returns 3.14
math.ldexp(0.5,8) : returns 128

skyMath math::linearInterp	(	inputValue	,
		scaleRangeMin	,
		scaleRangeMax	,
		minOut	,
		maxOut
	)

skyMath.linearInterp(inputValue, scaleRangeMin, scaleRangeMax, minOut, maxOut );

math::log

(

)

math.log() returns the inverse of math.exp(). math.exp(1) returns e.

The following is a Small Example on how to use this function:

math.log(532048240601) : returns 26.999999999998
math.log(3) : returns 1.0986122886681

math::log10

(

)

The Math abs function returns the base 10 logarithm of a given number. The number must be positive.

The following is a Small Example on how to use this function:

math.log10(100) : returns 2
math.log10(256) : returns 2.4082399653118
math.log10(-1) : returns nan -- can return -1.#INF on some Windows installs

math::max

(

)

The Math max function returns the maximum value from a variable length list of arguments.

The following is a Small Example on how to use this function:

math.max(1.2, -7, 3)    : returns 3
math.max(1.2, 7, 3)     : returns 7

Note that some operations on math.huge return a special "not-a-number" value that displays as nan. This is a bit of a misnomer. nan is a number type, though it's different from other numbers:

type(math.huge * 0) : returns number

math::min

(

)

The Math min function returns the minimum value from a variable length list of arguments.

The following is a Small Example on how to use this function:

math.min(1,2)           : returns 1
math.min(1.2, 7, 3)     : returns 1.2
math.min(1.2, -7, 3)    : returns -7

math::modf

(

)

The Math abs function always returns the non-negative number, of a given value.

The following is a Small Example on how to use this function:

math.modf(5)    : returns 5   0
math.modf(5.3)  : returns 5   0.3
math.modf(-5.3) : returns -5  -0.3

math::pi

(

)

This is the constant PI.

The following is a Small Example on how to use this function:

math.pi : returns 3.1415926535898

math::pow

(

)

math.pow() raises the first parameter to the power of the second parameter and returns the result.
The binary ^ operator performs the same job as math.pow(), i.e. math.pow(x,y) == x^y.

The following is a Small Example on how to use this function:

math.pow(100,0) : returns 1
math.pow(7,2)   : returns 49
math.pow(2,8)   : returns 256
math.pow(3,2.7) : returns 19.419023519771
5 ^ 2   : returns 25    
2^8 : returns 256

math::rad

(

)

The Math deg function allows you to convert from degrees to radians.

The following is a Small Example on how to use this function:

math.rad(180)   : 3.1415926535898
math.rad(1)     : 0.017453292519943

math::random

(

)

math.random() generates pseudo-random numbers uniformly distributed. Supplying argument alters its behaviour:

math.random() with no arguments generates a real number between 0 and 1.
math.random(upper) generates integer numbers between 1 and upper.
math.random(lower, upper) generates integer numbers between lower and upper.
The following is a Small Example on how to use this function:

math.random()       : returns 0.0012512588885159
math.random()       : returns 0.56358531449324
math.random(100)    : returns 20
math.random(100)    : returns 81
math.random(70,80)  : returns 76
math.random(70,80)  : returns 73

upper and lower must be integer. In other case Lua casts upper into an integer, sometimes giving math.floor(upper) and others math.ceil(upper), with unexpected results (the same for lower).

math::randomseed

(

)

The math.randomseed() function sets a seed for the pseudo-random generator: Equal seeds produce equal sequences of numbers.

The following is a Small Example on how to use this function:

math.randomseed(1234)
math.random() : returns 0.12414929654836
math.random() : returns 0.0065004425183874  
math.random() : returns 0.3894466994232

math.randomseed(1234)
math.random() : returns 0.12414929654836 
math.random() : returns 0.0065004425183874
math.random() : returns 0.3894466994232

math::sin

(

)

The Math sin function returns the cosine number for a given value in radians.

The following is a Small Example on how to use this function:

math.sin(0.123) : returns 0.12269009002432

math::sinh

(

)

The Math cosh function returns the hyperbolic sine number for a given value.

The following is a Small Example on how to use this function:

math.sinh(1) : returns 1.1752011936438

math::sqrt

(

)

The Math sqrt function returns the square root of a given number. Only non-negative arguments are allowed.

The following is a Small Example on how to use this function:

math.sqrt(100)  : returns 10
math.sqrt(1234) : returns 35.128336140501
math.sqrt(-7)   : returns -1.#IND

math::tan

(

)

The Math tan function returns the cosine number for a given value in radians.

The following is a Small Example on how to use this function:

math.tan(5/4) : returns 3.0095696738628
math.tan(.77) : returns 0.96966832796149

math::tanh

(

)

The Math cosh function returns the hyperbolic tangent[2] number for a given value.

The following is a Small Example on how to use this function:

math.tanh(1) : returns 0.76159415595576

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The documentation for this class was generated from the following file:

• LUA_API_Math.h