math

The math library provides a number of useful math functions as well as special functions for Base64, and hashing and digests. More are added as needed. To make your own contributions, see the page Pico Engine welcoming your contributions for step-by-step guidance.

General Functions

absolute value

abs(<num>) - absolute value of <num>

 
     n = math:abs(-12);     // n = 12

ceiling

ceiling(<num>) - the smallest integer not less than <num>

n = math:ceiling(2.78);    // n = 3

floor

floor(<num>) - the largest integer not greater than <num>

n = math:floor(2.78);    // n = 2

int

int(<num>) - the integer value of <num>

 
     n = math:int(2.999);     // n = 2

Only numbers are valid arguments to int. To coerce a string, use the Universal operator as(). 

random

To obtain a random number, please use a function from the random library

round

round(<num>) - convert <num> to the nearest integer.

n = math:round(2.1);    // n = 2
m = math:round(2.7);    // m = 3

round can take an optional second argument, the number of decimal places, which extends to negative values in an intuitive way.

math:round(4066.123,2)   // 4066.12
math:round(4066.123,0)   // 4066
math:round(4066.123,-2)  // 4100

Base64 Functions

math:base64encode(str, [encoding])

Given a string, str of type [encoding], return the base64 string. If the encoding is omitted, it defaults to utf8. 

math:base64encode(payload,"hex")

math:base64decode(str,[encoding])

Decode the given base64 string, str returning a value with a type of [ encoding ] . If the encoding is omitted, it defaults to utf8. 

math:base64decode(payload,"hex")

Hashing and Digest Functions

math:hashAlgorithms

An array of available hash algorithm names (strings)

 math:hashAlgorithms.klog() // ["sha256", "sha512", "DSA", ...]

math:hash(algorithm, str [, encoding])

Return the hash for the str using the given algorithm. Optionally specify the encoding "hex" (default) and "base64"

 math:hash("sha256", "hello") // "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"
 math:hash("sha256", "hello", "base64") // "LPJNul+wow4m6DsqxbninhsWHlwfp0JecwQzYpOLmCQ="

math:hmac(algorithm, key, message [, encoding])

Return an hmac string of message from the given hash algorithm and secret key. Optionally specify the encoding "hex" (default) and "base64"

 math:hmac("sha256", "a secret", "some message") // "86de43245b44531ac38b6a6a691996287d932a8dea03bc69b193b90caf48ff53"
 math:hmac("sha256", "a secret", "some message", "base64") // "ht5DJFtEUxrDi2pqaRmWKH2TKo3qA7xpsZO5DK9I/1M="

Planned but not yet implemented

exponent

exp(<num>) - return e (natural logrithm) raised to the <num>th power

      n = math:exp(2);

logarithm

log(<num>) - natural log of <num>

 n = math:log(2);

square root

sqrt(<num>) - square root of <num>

n = math:sqrt(2);

power

power(<num1>,<num1>) - <num1> to the <num2>th power.

 n = math:power(2,3);    //  n = 8

Other possibilities

See the page (Classic) math from the classic KRE.