Function Dump/Mathematical Functions: Difference between revisions

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>JulienDethurens
(MediaWiki doesn't include the current page in the "map", with subpages. Considering our template is meant to imitate MediaWiki's subpages "map", we should do the same thing. It looks ugly to include the current page, anyways, and it just takes up spa)
>JulienDethurens
(MediaWiki doesn't include the current page in the "map", with subpages. Considering our template is meant to imitate MediaWiki's subpages "map", we should do the same thing. It looks ugly to include the current page, anyways, and it just takes up spa)
(No difference)

Revision as of 21:23, 23 January 2012

This library is an interface to the standard C math library. It provides all its functions inside the table math. The functions are listed below.

math.abs(x)

Returns the absolute value of x.

print( math.abs(-5) )
5

math.acos(x)

Returns the arc cosine of x (in radians).

print( math.acos(-1) )
3.1415926535898

math.asin(x)

Returns the arc sine of x (in radians).

print( math.asin(0) )
0

math.atan(x)

Returns the arc tangent of x (in radians).

print( math.atan(1) )
0.78539816339745 (45 degrees)

math.atan2(y, x)

Returns the arc tangent of y/x (in radians), but uses the signs of both parameters to find the quadrant of the result. It also handles correctly the case of x being zero.

math.ceil(x)

Returns the smallest integer larger than or equal to x. Essentially, rounds a number to the next highest value

print( math.ceil(4.2) )
5

math.cos(x)

Returns the cosine of x (assumed to be in radians).

print( math.cos(1) )
0.54030230586814

math.cosh(x)

Returns the hyperbolic cosine of x.

print( math.cosh(1) )
1.5430806348152

math.deg(x)

Returns the angle x (given in radians) in degrees.

print( math.deg(math.pi / 2) )
90

math.exp(x)

Returns the the value e^x.

print( math.exp(1) )
2.718281828459

math.floor(x)

Returns the largest integer smaller than or equal to x.

print( math.floor(4.8) )
4

math.fmod(x, y)

Returns the remainder of the division of x by y that rounds the quotient towards zero.

print( math.fmod(10, 3) )
1

math.frexp(x)

Returns m and e such that x = m*2^e, e is an integer and the absolute value of m is in the range [0.5, 1) (or zero when x is zero).

print( math.frexp(0) )
0 0
print( math.frexp(4) )
0.5 3 (2^3/2 == 4)

math.huge

A representation of infinity, a value larger than or equal to any other numerical value.

print( math.huge )
1.#INF

math.ldexp(m, e)

Returns m*2^e (e should be an integer).

print( math.ldexp(2, 6) )
128 (i.e., 2*(2^6))


math.log(x)

Returns the natural logarithm of x.

print( math.log(2.718281828459045) )
1

math.log10(x)

Returns the base-10 logarithm of x.

print( math.log10(100) )
2

math.max(x, ···)

Returns the maximum value among its arguments.

print( math.max(1, 2, 3, 4, 5, 6, 7) )
7

math.min(x, ···)

Returns the minimum value among its arguments.

print( math.min(1, 2, 3, 4, 5, 6, 7) )
1

math.modf(x)

Returns two numbers, the integral part of x and the fractional part of x.

print( math.modf(2.5) )
2 0.5

math.pi

The value of pi. Pi is a mathematics term (not the baked good) that represents a very specific number.

print( math.pi )
3.1415926535898

math.pow(x, y)

Returns x^y. (You can also use the expression x^y to compute this value.)

print( math.pow(4, 2) )
16

math.rad(x)

Returns the angle x (given in degrees) in radians.

print( math.rad(90) )
1.5707963267949 (Which is pi/2)

math.random([m [, n]])

This function can be called 3 ways:

math.random(min,max) -- returns an Integer min-max
Example
local str = ""
for i = 1, 10 do
  local num = math.random(33, 126)
  str = str .. string.char(num)
end
print(str)  -- random string length 10
math.random() -- returns a Number value 0-1
Example
local color = Color3.new(math.random(), math.random(), math.random())
print(color)  -- random color3
math.random(max) -- returns an Integer 1-max
Example
local list = Workspace:GetChildren()
print( list[math.random(#list)] )  -- random item from list
local a = math.random(5)

The first example returns a random item from list, while the second returns an integer between one and five.


If the second number is less than first (or only number is less than 1), you'll get:

bad argument #n to 'random' (interval is empty)

This function is an interface to the simple pseudo-random generator function rand provided by ANSI C. (No guarantees can be given for its statistical properties.)

math.randomseed(x)

Sets x as the "seed" for the pseudo-random generator: equal seeds produce equal sequences of numbers.

math.sin(x)

Returns the sine of x (assumed to be in radians).

print( math.sin(math.pi / 2) )
1

math.sinh(x)

Returns the hyperbolic sine of x.

print( math.sinh(0) )
0

math.sqrt(x)

Returns the square root of x. You can also use the expression x^0.5 to compute this value, but it is less efficient.

math.tan(x)

Returns the tangent of x (assumed to be in radians).

print( math.tan(1) )
1.5574077246549

math.tanh(x)

Returns the hyperbolic tangent of x.

print( math.tanh(1) )
0.76159415595576