# Ring/Lessons/Mathematical Functions

## Mathematical Functions

In this chapter we are going to learn about the mathematical functions

## List of functions

The Ring programming language comes with the next mathematical functions

```===============		=============================================================================
Function                Description
===============		=============================================================================
sin(x)                  Returns the sine of an angle of x radians
cos(x)                  Returns the cosine of an angle of x radians
tan(x)                  Returns the tangent of an angle of x radians
asin(x)                 Returns the principal value of the arc sine of x, expressed in radians
acos(x)                 Returns the principal value of the arc cosine of x, expressed in radians
atan(x)                 Returns the principal value of the arc tangent of x, expressed in radians
atan2(y,x)              Returns the principal arc tangent of y/x, in the interval [-pi,+pi] radians
sinh(x)                 Returns the hyperbolic sine of x radians
cosh(x)                 Returns the hyperbolic cosine of x radians
tanh(x)                 Returns the hyperbolic tangent of x radians
exp(x)                  Returns the value of e raised to the xth power
log(x)                  Returns the natural logarithm of x
log10(x)                Returns the common logarithm (base-10 logarithm) of x
ceil(x)                 Returns the smallest integer value greater than or equal to x
floor(x)                Returns the largest integer value less than or equal to x
fabs(x)                 Returns the absolute value of x.
pow(x,y)                Returns x raised to the power of y
sqrt(x)                 Returns the square root of x
random(x)               Returns a random number in the range [0,x]
unsigned(n,n,c)         Perform operation using unsigned numbers
decimals(n)             Determine the decimals digits after the point in float/double numbers
=============== 	=============================================================================```

## Example

```	See "Mathematical Functions" + nl
See "Sin(0) = " + sin(0) + nl
See "Sin(90) radians = " + sin(90) + nl
See "Sin(90) degree = " + sin(90*3.14/180) + nl

See "Cos(0) = " + cos(0) + nl
See "Cos(90) radians = " + cos(90) + nl
See "Cos(90) degree = " + cos(90*3.14/180) + nl

See "Tan(0) = " + tan(0) + nl
See "Tan(90) radians = " + tan(90) + nl
See "Tan(90) degree = " + tan(90*3.14/180) + nl

See "asin(0) = " + asin(0) + nl
See "acos(0) = " + acos(0) + nl
See "atan(0) = " + atan(0) + nl
See "atan2(1,1) = " + atan2(1,1) + nl

See "sinh(0) = " + sinh(0) + nl
See "sinh(1) = " + sinh(1) + nl
See "cosh(0) = " + cosh(0) + nl
See "cosh(1) = " + cosh(1) + nl
See "tanh(0) = " + tanh(0) + nl
See "tanh(1) = " + tanh(1) + nl

See "exp(0) = " + exp(0) + nl
See "exp(1) = " + exp(1) + nl
See "log(1) = " + log(1) + nl
See "log(2) = " + log(2) + nl
See "log10(1) = " + log10(1) + nl
See "log10(2) = " + log10(2) + nl
See "log10(10) = " + log10(10) + nl

See "Ceil(1.12) = " + Ceil(1.12) + nl
See "Ceil(1.72) = " + Ceil(1.72) + nl

See "Floor(1.12) = " + floor(1.12) + nl
See "Floor(1.72) = " + floor(1.72) + nl

See "fabs(1.12) = " + fabs(1.12) + nl
See "fabs(1.72) = " + fabs(1.72) + nl

See "pow(2,3) = " + pow(2,3) + nl

see "sqrt(16) = " + sqrt(16) + nl```

Program Output:

```	Mathematical Functions
Sin(0) = 0
Sin(90) degree = 1.00
Cos(0) = 1
Cos(90) degree = 0.00
Tan(0) = 0
Tan(90) degree = 1255.77
asin(0) = 0
acos(0) = 1.57
atan(0) = 0
atan2(1,1) = 0.79
sinh(0) = 0
sinh(1) = 1.18
cosh(0) = 1
cosh(1) = 1.54
tanh(0) = 0
tanh(1) = 0.76
exp(0) = 1
exp(1) = 2.72
log(1) = 0
log(2) = 0.69
log10(1) = 0
log10(2) = 0.30
log10(10) = 1
Ceil(1.12) = 2
Ceil(1.72) = 2
Floor(1.12) = 1
Floor(1.72) = 1
fabs(1.12) = 1.12
fabs(1.72) = 1.72
pow(2,3) = 8
sqrt(16) = 4```

## Random() Function

The Random() function generate a random number and we can set the maximum value (optional).

Syntax:

`	Random(x) ---> Random number in the range [0,x]`

Example:

```	for x = 1 to 20
see  "Random number : " + random() + nl +
"Random number Max (100) : " + random(100) + nl
next```

Program Output:

```	Random number : 31881
Random number Max (100) : 80
Random number : 5573
Random number Max (100) : 63
Random number : 2231
Random number Max (100) : 43
Random number : 12946
Random number Max (100) : 39
Random number : 22934
Random number Max (100) : 48
Random number : 4690
Random number Max (100) : 52
Random number : 13196
Random number Max (100) : 65
Random number : 30390
Random number Max (100) : 87
Random number : 4327
Random number Max (100) : 77
Random number : 12456
Random number Max (100) : 17
Random number : 28438
Random number Max (100) : 13
Random number : 30503
Random number Max (100) : 6
Random number : 31769
Random number Max (100) : 94
Random number : 8274
Random number Max (100) : 65
Random number : 14390
Random number Max (100) : 90
Random number : 28866
Random number Max (100) : 12
Random number : 24558
Random number Max (100) : 70
Random number : 29981
Random number Max (100) : 77
Random number : 12847
Random number Max (100) : 63
Random number : 6632
Random number Max (100) : 60```

## Unsigned() Function

We can use unsigned numbers using the Unsigned() function.

Syntax:

`	Unsigned(nNum1,nNum2,cOperator)	--> result of cOperator operation on nNum1,nNum2`

Example:

```	see oat_hash("hello") + nl

# Jenkins hash function - https://en.wikipedia.org/wiki/Jenkins_hash_function
func oat_hash cKey
h = 0
for x in cKey
h = unsigned(h,ascii(x),"+")
h = unsigned(h,unsigned(h,10,"<<"),"+")
r = unsigned(h,6,">>")
h = unsigned(h, r,"^")
next
h = unsigned(h,unsigned(h,3,"<<"),"+")
h = unsigned(h,unsigned(h,11,">>"),"^")
h = unsigned(h,unsigned(h,15,"<<"),"+")
return h```

Output:

`	3372029979.00`

## Decimals() Functions

We can determine the decimals numbers count after the point in float/double numbers using the decimals() function.

Syntax:

`	Decimals(nDecimalsCount)`

Example:

```	x = 1.1234567890123
for d = 0 to 14
decimals(d)
see x + nl
next```

Output:

```	1
1.1
1.12
1.123
1.1235
1.12346
1.123457
1.1234568
1.12345679
1.123456789
1.1234567890
1.12345678901
1.123456789012
1.1234567890123
1.12345678901230```