API Reference

Wiki ▸ API Reference

Datalib API Reference

Below is the list of all top-level datalib functions and properties, grouped by category.

• Data Import
• Data Generators and Distributions
• Statistics
  • Summary Statistics
  • Distance and Correlation Measures
  • Modeling
  • Entropy Measures
  • Binning, Histograms and Profiles
• Group-By Aggregation
• Utilities
  • Type Checkers
  • Type Conversion
  • Object Helpers
  • Object Properties
  • Sorting
  • Strings
  • Miscellaneous
• String Formatting
  • Templates
  • Format Values
  • Auto-Format Values
  • Format Tables
  • Locales

Data Import

• dl.load - Load data from a URL or file.
• dl.load.headers - Custom request headers to include with all HTTP requests.
• dl.load.useXHR - Flag indicating if XMLHttpRequest should be used to load files.
• dl.load.sanitizeURL - Checks URLs for validity prior to loading.
• dl.read - Parse loaded data according to format types.
• dl.type - Return first non-null type in an array of values.
• dl.type.all - Return first non-null types for fields of an input data table.
• dl.type.infer - Perform type inference over an array of values.
• dl.type.inferAll - Perform type inference over an input data table.
• dl.json - Load and parse JSON data.
• dl.csv - Load and parse CSV (comma-separated values) data.
• dl.tsv - Load and parse TSV (tab-separated values) data.
• dl.dsv - Load and parse delimited text with a custom delimiter.
• dl.topojson - Load and parse TopoJSON data.
• dl.treejson - Load and parse JSON-format hierarchy data.

Data Generators and Distributions

• dl.zeros - Generate an array of zeros.
• dl.repeat - Generate an array of a repeated value.
• dl.range - Generate a range of numeric values.
• dl.random.bootstrap - Generate bootstrapped samples.
• dl.random.uniform - Model uniformly distributed numbers.
• dl.random.integer - Model uniformly distributed integers.
• dl.random.normal - Model normally (gaussian) distributed numbers.

Statistics

Summary Statistics

• dl.count - Count the number of values.
• dl.count.valid - Count the number of valid (non-null/undefined/NaN) values.
• dl.count.missing - Count the number of null or undefined values.
• dl.count.distinct - Count the number of distinct values.
• dl.count.map - Construct a map of counts per distinct value.
• dl.unique - Collect unique values.
• dl.median - Compute the median of an array of numbers.
• dl.quartile - Compute the quartile boundaries of an array of numbers.
• dl.quantile - Compute the quantile of a sorted array of numbers.
• dl.sum - Compute the sum of an array of numbers.
• dl.mean - Compute the mean (average) of an array of numbers.
• dl.mean.geometric - Compute the geometric mean of an array of positive numbers.
• dl.mean.harmonic - Compute the harmonic mean of an array of numbers.
• dl.variance - Compute the sample variance of an array of numbers.
• dl.stdev - Compute the sample standard deviation of an array of numbers.
• dl.modeskew - Compute the Pearson mode skewness of an array of numbers.
• dl.min - Find the minimum value of an array of values.
• dl.max - Find the maximum value of an array of values.
• dl.extent - Find the minimum and maximum of an array of values.
• dl.extent.index - Find the integer indices of the minimum and maximum values.

Distance and Correlation Measures

• dl.dot - Compute the dot product of two arrays of numbers.
• dl.rank - Compute ascending rank scores for an array of values.
• dl.cor - Compute the sample product-moment correlation of two arrays of numbers.
• dl.cor.rank - Compute the Spearman rank correlation of two arrays of values.
• dl.cor.dist - Compute the distance correlation of two arrays of numbers.
• dl.dist - Compute the vector distance between two arrays of numbers.
• dl.dist.mat - Construct a mean-centered distance matrix for an array of numbers.
• dl.covariance - Compute the covariance between two arrays of numbers.
• dl.cohensd - Compute Cohen's d effect size between two arrays of numbers.

Modeling

• dl.linearRegression - Fit a univariate linear regression model.
• dl.bootstrap.ci - Compute confidence intervals by bootstrapping.
• dl.z.ci - Compute confidence intervals assuming a normal distribution.
• dl.z.test - Perform a z-test of means.

Entropy Measures

• dl.entropy - Compute the Shannon entropy of an array of counts.
• dl.mutual - Compute mutual information and distance statistics.
• dl.mutual.info - Compute the mutual information between discrete variables.
• dl.mutual.dist - Compute the information distance between discrete variables.

Binning, Histograms and Profiles

• dl.bins - Determine quantitative bins (e.g., for a histogram).
• dl.bins.date - Determine bins over common date/time units.
• dl.$bin - Create an accessor that maps values to binned values.
• dl.histogram - Compute a histogram for an array of values.
• dl.profile - Compute a profile of summary statistics for a variable.
• dl.summary - Compute profiles for all variables in a data set.

Group-By Aggregation

• dl.groupby - Create a group-by aggregation query.
• groupby.stream - Indicate if the aggregation should accept streaming removes.
• groupby.key - Specify a key function for processing streaming removes.
• groupby.summarize - Specify summary aggregates (min, max, median, etc.).
• groupby.count - Specify a single count summary aggregate.
• groupby.execute - Aggregate an array of values and return the result.
• groupby.insert - Add an array of values to the aggregation.
• groupby.remove - Remove an array of values from the aggregation.
• groupby.result - Return the current group-by aggregation result.
• groupby.clear - Clear all current results from the aggregation.

Utilities

Type Checkers

• dl.isObject - Check if a value is an Object.
• dl.isFunction - Check if a value is a Function.
• dl.isString - Check if a value is a String.
• dl.isArray - Check if a value is an Array.
• dl.isNumber - Check if a value is a Number.
• dl.isBoolean - Check if a value is a Boolean.
• dl.isDate - Check if a value is a Date.
• dl.isValid - Check if a value is not null, undefined or NaN.
• dl.isBuffer - Check if a value is a Buffer.

Type Conversion

• dl.number - Coerce a value to a number, ignoring nulls.
• dl.boolean - Coerce a value to a Boolean, ignoring nulls.
• dl.date - Coerce (parse) a value to a Date, ignoring nulls.
• dl.array - Wrap non-array values in a single-element array, ignoring nulls.
• dl.str - Coerce values to JSON-style strings with escaped quotes.

Object Helpers

• dl.duplicate - Create a deep duplicate of an object.
• dl.equal - Check if two objects are deeply equal.
• dl.extend - Extend an object with the properties of another.
• dl.keys - Extract an array of an Object's keys.
• dl.vals - Extract an array of an Object's values.
• dl.toMap - Generate a boolean map Object from an array.

Object Properties

• dl.field - Parse a string property descriptor (e.g., "foo.bar") to an array.
• dl.accessor - Parse a string property descriptor to an accessor (getter) function.
• dl.$ - A shorthand alias for dl.accessor.
• dl.mutator - Parse a string property descriptor to a mutator (setter) function.
• dl.$valid - Create an accessor that indicates if an extracted value is valid.
• dl.$length - Create an accessor that extracts the length of String or Array values.
• dl.$in - Create an accessor that tests if an extracted value is contained in a set.
• dl.$year - Create an accessor that extracts the year from Date values.
• dl.$utcYear - Create an accessor that extracts the UTC year from Date values.
• dl.$month - Create an accessor that extracts the month from Date values.
• dl.$utcMonth - Create an accessor that extracts the UTC month from Date values.
• dl.$date - Create an accessor that extracts the day of the month from Date values.
• dl.$utcDate - Create an accessor that extracts the UTC day of the month from Date values.
• dl.$day - Create an accessor that extracts the day of the week from Date values.
• dl.$utcDay - Create an accessor that extracts the UTC day of the week from Date values.
• dl.$hour - Create an accessor that extracts the hour from Date values.
• dl.$utcHour - Create an accessor that extracts the UTC hour from Date values.
• dl.$minute - Create an accessor that extracts the minute from Date values.
• dl.$utcMinute - Create an accessor that extracts the UTC minute from Date values.

Sorting

• dl.comparator - Generate a comparison function based on provided fields.
• dl.cmp - Default comparison function across data types.
• dl.numcmp - Default comparison function for numerical data.
• dl.stablesort - Sorting method with guaranteed stable ordering.
• dl.permute - Fisher-Yates permutation of an array.

Strings

• dl.keystr - Map an array of values to a string to use as a hash key.
• dl.pad - Pads a string to a specified length.
• dl.truncate - Truncate a string value to limit its length.

Miscellaneous

• dl.identity - Identity function that simply returns an input value.
• dl.length - Function that returns the length of a String or Array.
• dl.true - Function that simply returns true.
• dl.false - Function that simply returns false.

String Formatting

Templates

• dl.template - Generate a string template function for data objects.

Format Values

• dl.format.number - Format numerical values.
• dl.format.numberPrefix - Format numerical values according to an SI prefix.
• dl.format.time - Format datetime values in the local timezone.
• dl.format.utc - Format datetime values in Coordinated Universal Time (UTC).

Auto-Format Values

• dl.format.auto.number - Automatically format numerical values.
• dl.format.auto.linear - Automatically format a linear range of numbers.
• dl.format.auto.time - Automatically format local datetime values.
• dl.format.auto.utc - Automatically format UTC datetime values.

Format Tables

• dl.format.table - Create a formatted print string for table data.
• dl.format.summary - Create a formatted print string for table summary data.

Locales

• dl.format.locale - Set the locale for number and datetime formatting.
• dl.format.numberLocale - Set the locale for number formatting.
• dl.format.timeLocale - Set the locale for datetime formatting.