psMathStats

PseudoSavant Math and Statistics Library

Version 2.0

by Paul Ellis

What does psMathStats do?

It is a library for performing some basic math and statistics calculations such as the standard deviation of an array of numbers, the product of a set of numbers, or a pseudo random number generator that generates normally distributed numbers.

Array Methods

• Array.sample(samples): Returns a Array with samples number of random samples from the source Array. It can be used before other Array methods (e.g. myHugeArray.sample(20000).stdDev()) to significantly improve performance while sacrificing some accuracy.
• Array.sum(): Sums all values in a Array
• Array.mean(): Returns the arithmetic mean of the source Array
• Array.median(): Returns the the median value of the Array
• Array.percentile(): Returns the value at the given percentile for the Array
• Array.variance(): Returns the Variance of the source Array
• Array.stdDev(): Returns the Standard Deviation of the source Array
• Array.max(): Returns the highest numeric value of a Array
• Array.min(): Returns the lowest numeric value of a Array
• Array.sortNumber(invert): Returns the Array sorted ascendingly, or decendingly if invert = true
• Array.histogram(): Returns an object where the key equals the item and the value equals the count of the times that item occured in the Array
• Array.countByType(): Returns an object that shows the total count of each type in a Array

Note

psMathStats extends the native Array.prototype. Be careful if you try to loop over an array using for (var i in arr)

Math Functions

• ps.math.even(n): Returns true if n is an even number
• ps.math.odd(n): Returns true if n is an odd number
• ps.math.fact(n): Calculates the factorial for any given integer n
• ps.math.product(n, n, n...): Returns the product of all of the arguments
• ps.math.randomBetween(floor, ceiling, digits): Generates a random number between two numbers, defaulting to integers (digits = 0)
• ps.math.randomNormal(mean, stdDev): Generates normally distributed random numbers for the given mean and stardard deviation. Defaults to mean = 0, stdDev = 1.

Stats Functions

• ps.stats.normsinv(p): returns the inverse of the standard normal cumulative distribution for a given p percentile

License

BSD