Arrays reference

The 44 functions and 0 values of array: signature, effects, phase, cost and tested examples.

An array is an ordered list of values of one kind. Many functions here are written as methods: a.push(x) is array.push(a, x).

Functions#

array.abs#

array.abs([array])

A new array with the absolute value of each element.

Effects: builds a new value whose size follows its arguments (counted in the memory ledger).
Phase: every bar.
Cost: allocates: the memory ledger counts what it builds.
Returns: an array.

array.all#

array.all([array])

True when the array is not empty and every element is true.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Returns: true or false.

array.any#

array.any([array])

True when at least one element is true.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Returns: true or false.

array.at#

array.at(array, index)

The element at an index.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Examples: Guarded read, Read past the end of an array.

array.avg#

array.avg([array])

A statistic of the elements.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.

array.binary_search#

array.binary_search([array], [value])

The index of a value in a sorted array, or -1 when the value is not there.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Returns: a whole number.

array.binary_search_leftmost#

array.binary_search_leftmost([array], [value])

The index of the first element equal to the value in a sorted array; when none is equal, the index of the element just below where the value would sit.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Returns: a whole number.

array.binary_search_rightmost#

array.binary_search_rightmost([array], [value])

The index of the last element equal to the value in a sorted array; when none is equal, the index of the element just above where the value would sit.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Returns: a whole number.

array.clear#

array.clear(array)

Removes every element.

Effects: changes a collection in place.
Phase: every bar.
Cost: a fixed number of operations.

array.concat#

array.concat([array], [other])

Appends the elements of another array to the array and returns it.

Effects: changes a collection in place; builds a new value whose size follows its arguments (counted in the memory ledger).
Phase: every bar.
Cost: allocates: the memory ledger counts what it builds.
Returns: the array.

array.contains#

array.contains([array], [value])

True when the array holds the value.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.

array.copy#

array.copy([array])

A copy of the array.

Effects: builds a new value whose size follows its arguments (counted in the memory ledger).
Phase: every bar.
Cost: allocates: the memory ledger counts what it builds.

array.covariance#

array.covariance([array], [other], [biased])

The covariance of two arrays of the same size; pairs that hold na are skipped, and biased divides by the count instead of the count minus one.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Returns: a number.

array.fill#

array.fill([array], [value], [from], [to])

Sets the elements from index from up to, not including, to to one value; without a range it fills the whole array.

Effects: changes a collection in place.
Phase: every bar.
Cost: a fixed number of operations.

array.first#

array.first([array])

The first or last element.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.

array.index_of#

array.index_of([array], [value])

The index of the first or last element equal to the value, or -1.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.

array.insert#

array.insert([array], [index], [value])

Inserts a value at an index.

Effects: changes a collection in place; builds a new value whose size follows its arguments (counted in the memory ledger).
Phase: every bar.
Cost: allocates: the memory ledger counts what it builds.

array.join#

array.join([array], [separator])

The elements as one text, with separator between.

Effects: builds a new value whose size follows its arguments (counted in the memory ledger).
Phase: every bar.
Cost: allocates: the memory ledger counts what it builds.

array.last#

array.last([array])

The first or last element.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Examples: Guarded read, Read past the end of an array.

array.last_index_of#

array.last_index_of([array], [value])

The index of the first or last element equal to the value, or -1.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.

array.max#

array.max([array], [nth])

A statistic of the elements.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Examples: Rolling median band, Array read with brackets.

array.median#

array.median([array])

A statistic of the elements.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Examples: Rolling median band.

array.min#

array.min([array], [nth])

A statistic of the elements.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Examples: Rolling median band, Array read with brackets.

array.mode#

array.mode([array])

A statistic of the elements.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.

array.new#

array.new([size], [initial])

Makes an array of size elements, each initial.

Effects: builds a new value whose size follows its arguments (counted in the memory ledger).
Phase: every bar.
Cost: allocates: the memory ledger counts what it builds.

array.percent_rank#

array.percent_rank([array], [index])

The percentage of the elements that are less than or equal to the element at index.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Returns: a number from 0 to 100.

array.percentile#

array.percentile([array], [percent])

The value at a percentage of the sorted elements, interpolated between the two closest ranks.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Returns: a number.
Examples: Rolling median band, Array read with brackets.

array.percentile_nearest#

array.percentile_nearest([array], [percent])

The value at a percentage of the sorted elements, taken at the nearest rank.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Returns: a number.

array.pop#

array.pop(array)

Removes and gives the last element.

Effects: changes a collection in place.
Phase: every bar.
Cost: a fixed number of operations.

array.push#

array.push(array, value)

Adds a value at the end.

Effects: changes a collection in place; builds a new value whose size follows its arguments (counted in the memory ledger).
Phase: every bar.
Cost: allocates: the memory ledger counts what it builds.
Examples: Rolling median band, Swing high path, Guarded read, Array read with brackets.

array.range#

array.range([array])

A statistic of the elements.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.

array.remove#

array.remove(array, index)

Removes and gives the element at an index.

Effects: changes a collection in place.
Phase: every bar.
Cost: a fixed number of operations.

array.reverse#

array.reverse([array])

Reverses the order in place.

Effects: changes a collection in place.
Phase: every bar.
Cost: a fixed number of operations.

array.set#

array.set(array, index, value)

Sets the element at an index.

Effects: changes a collection in place.
Phase: every bar.
Cost: a fixed number of operations.

array.shift#

array.shift([array])

Removes and gives the first element.

Effects: changes a collection in place.
Phase: every bar.
Cost: a fixed number of operations.
Examples: Rolling median band, Swing high path, Array read with brackets.

array.size#

array.size(array)

The number of elements.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.
Examples: Rolling median band, Swing high path, Guarded read, Array read with brackets.

array.slice#

array.slice([array], [from], [to])

A copy of part of the array.

Effects: builds a new value whose size follows its arguments (counted in the memory ledger).
Phase: every bar.
Cost: allocates: the memory ledger counts what it builds.

array.sort#

array.sort([array], [order])

Sorts the array in place, ascending or descending.

Effects: changes a collection in place.
Phase: every bar.
Cost: a fixed number of operations.

array.sort_indices#

array.sort_indices([array], [order])

A new array with the indexes that would put the elements in order, ascending or descending.

Effects: builds a new value whose size follows its arguments (counted in the memory ledger).
Phase: every bar.
Cost: allocates: the memory ledger counts what it builds.
Returns: an array of whole numbers.

array.standardize#

array.standardize([array])

A new array with each element as a z-score: its distance from the mean in standard deviations.

Effects: builds a new value whose size follows its arguments (counted in the memory ledger).
Phase: every bar.
Cost: allocates: the memory ledger counts what it builds.
Returns: an array of numbers.

array.stdev#

array.stdev([array], [biased])

A statistic of the elements.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.

array.sum#

array.sum([array])

A statistic of the elements.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.

array.unshift#

array.unshift([array], [value])

Adds a value at the start.

Effects: changes a collection in place; builds a new value whose size follows its arguments (counted in the memory ledger).
Phase: every bar.
Cost: allocates: the memory ledger counts what it builds.

array.variance#

array.variance([array], [biased])

A statistic of the elements.

Effects: none: the result depends on the arguments only.
Phase: every bar.
Cost: a fixed number of operations.