Module

Hylograph.Scale

Package: purescript-hylograph-selection
Repository: afcondon/purescript-hylograph-selection

Hylograph.Scale - Type-safe scales with functional programming idioms

This module provides D3-compatible scales with PureScript type safety and functional programming abstractions. Uses d3-scale-chromatic.js via FFI.

Basic Usage

import Hylograph.Scale (linear, domain, range, apply, ticks)

-- Create a linear scale
myScale = linear # domain [0.0, 100.0] # range [0.0, 800.0]

-- Apply the scale
pixelX = apply myScale 50.0  -- Returns 400.0

-- Get tick marks
tickValues = ticks 10 myScale  -- Returns nice tick values

Functional Idioms

Scales can be composed and transformed:

-- Compose scales
timeToPixel = timeScale `andThen` positionScale

-- Transform with Profunctor-like operations
celsiusScale = fahrenheitScale # contramap fahrenheitToCelsius

#Scale Source

data Scale t0 t1 t2

A scale maps values from a domain to a range The phantom types track:

domain - the input type
range - the output type
kind - the scale kind (Continuous, Ordinal, Band, etc.)

#Continuous Source

data Continuous

Phantom type for continuous scales (Linear, Log, Pow, etc.)

#Ordinal Source

data Ordinal

Phantom type for ordinal scales

#Band Source

data Band

Phantom type for band scales

#Point Source

data Point

Phantom type for point scales

#Time Source

data Time

Phantom type for time scales

#ContinuousScale Source

type ContinuousScale = Scale Number Number Continuous

Convenient type aliases

#OrdinalScale Source

type OrdinalScale domain range = Scale domain range Ordinal

#BandScale Source

type BandScale domain = Scale domain Number Band

#TimeScale Source

type TimeScale = Scale JSDate Number Time

#linear Source

linear :: ContinuousScale

Create a linear scale Maps domain values linearly to range values

scale = linear # domain [0.0, 100.0] # range [0.0, 500.0]
apply scale 50.0  -- Returns 250.0

#log Source

log :: ContinuousScale

Create a logarithmic scale Uses log transformation - domain must not include zero

scale = log # domain [1.0, 1000.0] # range [0.0, 300.0]

#pow Source

pow :: ContinuousScale

Create a power scale with configurable exponent

scale = pow # exponent 2.0 # domain [0.0, 100.0] # range [0.0, 500.0]

#sqrt Source

sqrt :: ContinuousScale

Create a square root scale (pow with exponent 0.5)

Useful for sizing circles by area

radiusScale = sqrt # domain [0.0, maxValue] # range [0.0, 50.0]

#symlog Source

symlog :: ContinuousScale

Create a symlog scale (symmetric log) Handles negative values and zero gracefully

scale = symlog # constant 1.0 # domain [-100.0, 100.0] # range [0.0, 500.0]

#JSDate Source

data JSDate

JavaScript Date object for time scales Compatible with native JS Date, can be created via FFI or js-date library

#scaleTime Source

scaleTime :: TimeScale

Create a time scale for local time

#scaleUtc Source

scaleUtc :: TimeScale

Create a UTC time scale

#Sequential Source

data Sequential

Phantom type for sequential scales (color gradients)

#Diverging Source

data Diverging

Phantom type for diverging scales (two-directional color gradients)

#SequentialScale Source

type SequentialScale = Scale Number String Sequential

#DivergingScale Source

type DivergingScale = Scale Number String Diverging

#sequential Source

sequential :: Interpolator String -> SequentialScale

#sequentialLog Source

sequentialLog :: Interpolator String -> SequentialScale

#sequentialSqrt Source

sequentialSqrt :: Interpolator String -> SequentialScale

#sequentialSymlog Source

sequentialSymlog :: Interpolator String -> SequentialScale

#diverging Source

diverging :: Interpolator String -> DivergingScale

#divergingLog Source

divergingLog :: Interpolator String -> DivergingScale

#divergingSqrt Source

divergingSqrt :: Interpolator String -> DivergingScale

#divergingSymlog Source

divergingSymlog :: Interpolator String -> DivergingScale

#Quantize Source

data Quantize

Phantom type for quantize scales (continuous → discrete buckets)

#Quantile Source

data Quantile

Phantom type for quantile scales (continuous → discrete based on quantiles)

#QuantizeScale Source

type QuantizeScale r = Scale Number r Quantize

#QuantileScale Source

type QuantileScale r = Scale Number r Quantile

#scaleQuantize Source

scaleQuantize :: forall r. QuantizeScale r

Create a quantize scale Maps continuous domain to discrete range (uniform intervals)

colorScale = scaleQuantize
  # domain [0.0, 100.0]
  # range ["low", "medium", "high"]

#scaleQuantile Source

scaleQuantile :: forall r. QuantileScale r

Create a quantile scale Maps continuous domain to discrete range based on quantiles

colorScale = scaleQuantile
  # domain [0.0, 25.0, 50.0, 75.0, 100.0]
  # range ["Q1", "Q2", "Q3", "Q4"]

#ordinal Source

ordinal :: forall d r. OrdinalScale d r

Create an ordinal scale Maps discrete domain values to discrete range values

colorScale = ordinal
  # domain ["a", "b", "c"]
  # range ["red", "green", "blue"]

#band Source

band :: forall d. BandScale d

Create a band scale Maps discrete domain values to continuous bands with configurable padding

xScale = band
  # domain ["Mon", "Tue", "Wed", "Thu", "Fri"]
  # range [0.0, 500.0]
  # padding 0.1

#point Source

point :: forall d. BandScale d

Create a point scale Like band but with zero bandwidth - just points

xScale = point
  # domain ["A", "B", "C"]
  # range [0.0, 500.0]

#domain Source

domain :: forall d r k. Array d -> Scale d r k -> Scale d r k

Set the domain (input extent) of a scale

For continuous scales: [min, max] (can include intermediate values for piecewise) For ordinal/band: array of discrete values

#range Source

range :: forall d r k. Array r -> Scale d r k -> Scale d r k

Set the range (output extent) of a scale

For continuous scales: [min, max] For band scales: [start, end] of the band space

#clamp Source

clamp :: forall d r k. Boolean -> Scale d r k -> Scale d r k

Enable or disable clamping When enabled, output is constrained to the range even for out-of-domain inputs

#nice Source

nice :: forall r k. Scale Number r k -> Scale Number r k

Extend the domain to nice round values

#niceCount Source

niceCount :: forall r k. Int -> Scale Number r k -> Scale Number r k

Extend the domain to nice round values with specified tick count hint

#padding Source

padding :: forall d. Number -> BandScale d -> BandScale d

Set padding for band scales (both inner and outer)

#paddingInner Source

paddingInner :: forall d. Number -> BandScale d -> BandScale d

Set inner padding (between bands) for band scales

#paddingOuter Source

paddingOuter :: forall d. Number -> BandScale d -> BandScale d

Set outer padding (before first and after last band) for band scales

#align Source

align :: forall d. Number -> BandScale d -> BandScale d

Set alignment for band scales (0 = left, 0.5 = center, 1 = right)

#round Source

round :: forall d r k. Boolean -> Scale d r k -> Scale d r k

Enable rounding of output values

#base Source

base :: forall r. Number -> Scale Number r Continuous -> Scale Number r Continuous

Set the base for logarithmic scales (default 10)

#exponent Source

exponent :: forall r. Number -> Scale Number r Continuous -> Scale Number r Continuous

Set the exponent for power scales

#constant Source

constant :: forall r. Number -> Scale Number r Continuous -> Scale Number r Continuous

Set the constant for symlog scales

#applyScale Source

applyScale :: forall d r k. Scale d r k -> d -> r

Apply a scale to a value

scale = linear # domain [0.0, 100.0] # range [0.0, 500.0]
applyScale scale 50.0  -- Returns 250.0

#invert Source

invert :: forall r. Scale Number r Continuous -> r -> Maybe Number

Invert a continuous scale (range value → domain value)

scale = linear # domain [0.0, 100.0] # range [0.0, 500.0]
invert scale 250.0  -- Returns Just 50.0

#ticks Source

ticks :: forall r k. Int -> Scale Number r k -> Array Number

Generate tick values for a continuous scale

scale = linear # domain [0.0, 100.0] # range [0.0, 500.0]
ticks 5 scale  -- Returns [0.0, 20.0, 40.0, 60.0, 80.0, 100.0]

#tickFormat Source

tickFormat :: forall r k. Int -> String -> Scale Number r k -> (Number -> String)

Get a tick formatter function

#bandwidth Source

bandwidth :: forall d. BandScale d -> Number

Get the bandwidth of a band scale

#step Source

step :: forall d. BandScale d -> Number

Get the step size of a band scale (bandwidth + padding)

#copy Source

copy :: forall d r k. Scale d r k -> Scale d r k

Create a copy of a scale

#andThen Source

andThen :: forall a b c k1 k2. Scale a b k1 -> Scale b c k2 -> (a -> c)

Compose two scales: apply first, then second

-- Time → normalized → pixels
combined = timeScale `andThen` pixelScale

#contramap Source

contramap :: forall a a' b k. (a' -> a) -> Scale a b k -> (a' -> b)

Transform the domain type (contravariant)

-- Convert Celsius input to a Fahrenheit scale
celsiusScale = fahrenheitScale # contramap celsiusToFahrenheit

#map Source

map :: forall a b b' k. (b -> b') -> Scale a b k -> (a -> b')

Transform the range type (covariant/functor-like)

-- Add offset to all positions
offsetScale = positionScale # map (_ + 50.0)

#dimap Source

dimap :: forall a a' b b' k. (a' -> a) -> (b -> b') -> Scale a b k -> (a' -> b')

Transform both domain and range (profunctor-like)

transformed = scale # dimap preprocess postprocess

#Interpolator Source

type Interpolator a = Number -> a

An interpolator maps [0, 1] to a value

#interpolateNumber Source

interpolateNumber :: Number -> Number -> Interpolator Number

Linear number interpolation

#interpolateRgb Source

interpolateRgb :: String -> String -> Interpolator String

RGB color interpolation

#interpolateHsl Source

interpolateHsl :: String -> String -> Interpolator String

#schemeCategory10 Source

schemeCategory10 :: Array String

Category10 color scheme (10 colors)

#schemeCategory10At Source

schemeCategory10At :: Int -> String

Get a Category10 color by index (wraps around modularly) Useful for coloring nodes by group number

fill = schemeCategory10At node.group

#schemeTableau10 Source

schemeTableau10 :: Array String

Tableau10 color scheme (10 colors) Modern, accessible categorical palette

#schemeTableau10At Source

schemeTableau10At :: Int -> String

Get a Tableau10 color by index (wraps around modularly) Useful for coloring categories in visualizations

fill = schemeTableau10At categoryIndex

#schemePaired Source

schemePaired :: Array String

Paired color scheme (12 colors)

#schemePairedAt Source

schemePairedAt :: Int -> String

Get a Paired color by index (wraps around modularly)

#schemeSet1 Source

schemeSet1 :: Array String

Set1 color scheme (9 colors)

#schemeSet2 Source

schemeSet2 :: Array String

Set2 color scheme (8 colors)

#schemeSet3 Source

schemeSet3 :: Array String

Set3 color scheme (12 colors)

#schemeAccent Source

schemeAccent :: Array String

Accent color scheme (8 colors)

#schemeDark2 Source

schemeDark2 :: Array String

Dark2 color scheme (8 colors)

#schemePastel1 Source

schemePastel1 :: Array String

Pastel1 color scheme (9 colors)

#schemePastel2 Source

schemePastel2 :: Array String

Pastel2 color scheme (8 colors)

#interpolateBlues Source

interpolateBlues :: Interpolator String

Blues single-hue sequential

#interpolateGreens Source

interpolateGreens :: Interpolator String

Greens single-hue sequential

#interpolateGreys Source

interpolateGreys :: Interpolator String

Greys single-hue sequential

#interpolateOranges Source

interpolateOranges :: Interpolator String

Oranges single-hue sequential

#interpolatePurples Source

interpolatePurples :: Interpolator String

Purples single-hue sequential

#interpolateReds Source

interpolateReds :: Interpolator String

Reds single-hue sequential

#interpolateViridis Source

interpolateViridis :: Interpolator String

Viridis perceptually-uniform colormap

#interpolatePlasma Source

interpolatePlasma :: Interpolator String

Plasma colormap

#interpolateInferno Source

interpolateInferno :: Interpolator String

Inferno colormap

#interpolateMagma Source

interpolateMagma :: Interpolator String

Magma colormap

#interpolateTurbo Source

interpolateTurbo :: Interpolator String

Turbo colormap (rainbow-like but more perceptual)

#interpolateWarm Source

interpolateWarm :: Interpolator String

Warm colormap (red to yellow)

#interpolateCool Source

interpolateCool :: Interpolator String

Cool colormap (cyan to purple)

#interpolateRainbow Source

interpolateRainbow :: Interpolator String

Rainbow colormap

#interpolateCividis Source

interpolateCividis :: Interpolator String

Cividis colormap (colorblind-friendly)

#interpolateCubehelixDefault Source

interpolateCubehelixDefault :: Interpolator String

Cubehelix default colormap

#interpolateBuGn Source

interpolateBuGn :: Interpolator String

Blue-Green sequential

#interpolateBuPu Source

interpolateBuPu :: Interpolator String

Blue-Purple sequential

#interpolateGnBu Source

interpolateGnBu :: Interpolator String

Green-Blue sequential

#interpolateOrRd Source

interpolateOrRd :: Interpolator String

Orange-Red sequential

#interpolatePuBuGn Source

interpolatePuBuGn :: Interpolator String

Purple-Blue-Green sequential

#interpolatePuBu Source

interpolatePuBu :: Interpolator String

Purple-Blue sequential

#interpolatePuRd Source

interpolatePuRd :: Interpolator String

Purple-Red sequential

#interpolateRdPu Source

interpolateRdPu :: Interpolator String

Red-Purple sequential

#interpolateYlGnBu Source

interpolateYlGnBu :: Interpolator String

Yellow-Green-Blue sequential

#interpolateYlGn Source

interpolateYlGn :: Interpolator String

Yellow-Green sequential

#interpolateYlOrBr Source

interpolateYlOrBr :: Interpolator String

Yellow-Orange-Brown sequential

#interpolateYlOrRd Source

interpolateYlOrRd :: Interpolator String

Yellow-Orange-Red sequential

#interpolateRdYlGn Source

interpolateRdYlGn :: Interpolator String

Red-Yellow-Green diverging

#interpolateRdBu Source

interpolateRdBu :: Interpolator String

Red-Blue diverging

#interpolatePiYG Source

interpolatePiYG :: Interpolator String

Pink-Yellow-Green diverging

#interpolateBrBG Source

interpolateBrBG :: Interpolator String

Brown-Blue-Green diverging

#interpolatePRGn Source

interpolatePRGn :: Interpolator String

Purple-Red-Green diverging

#interpolateSpectral Source

interpolateSpectral :: Interpolator String

Spectral diverging

#interpolateRdGy Source

interpolateRdGy :: Interpolator String

Red-Grey diverging

#interpolateRdYlBu Source

interpolateRdYlBu :: Interpolator String

Red-Yellow-Blue diverging

#interpolateSinebow Source

interpolateSinebow :: Interpolator String

Sinebow cyclical colormap

Modules: Data.DependencyGraph; Hylograph.AST; Hylograph.Axis.Axis; Hylograph.Brush; Hylograph.Brush.FFI; Hylograph.Brush.Types; Hylograph.Classify; Hylograph.Data.Graph; Hylograph.Data.Graph.Algorithms; Hylograph.Data.Node; Hylograph.Data.Tree; Hylograph.Expr.Animation; Hylograph.Expr.Attr; Hylograph.Expr.Datum; Hylograph.Expr.Expr; Hylograph.Expr.Friendly; Hylograph.Expr.Integration; Hylograph.Expr.Interpreter.CodeGen; Hylograph.Expr.Interpreter.Eval; Hylograph.Expr.Interpreter.Meta; Hylograph.Expr.Interpreter.PureSVG; Hylograph.Expr.Interpreter.SVG; Hylograph.Expr.Path; Hylograph.Expr.Path.Generators; Hylograph.Expr.Sugar; Hylograph.Expr.Units; Hylograph.HATS; Hylograph.HATS.Friendly; Hylograph.HATS.InterpreterTick; Hylograph.HATS.Transitions; Hylograph.Interaction.Brush; Hylograph.Interaction.Coordinated; Hylograph.Interaction.Pointer; Hylograph.Interaction.Zoom; Hylograph.Internal.Attribute; Hylograph.Internal.Behavior.FFI; Hylograph.Internal.Behavior.Types; Hylograph.Internal.Capabilities.Selection; Hylograph.Internal.Capabilities.Transition; Hylograph.Internal.FFI; Hylograph.Internal.Selection.Join; Hylograph.Internal.Selection.Operations; Hylograph.Internal.Selection.Operations.Conversions; Hylograph.Internal.Selection.Operations.Helpers; Hylograph.Internal.Selection.Operations.Selection; Hylograph.Internal.Selection.Query; Hylograph.Internal.Selection.Types; Hylograph.Internal.Transition.FFI; Hylograph.Internal.Transition.Manager; Hylograph.Internal.Transition.Scene; Hylograph.Internal.Transition.Types; Hylograph.Internal.Types; Hylograph.Interpreter.D3; Hylograph.Interpreter.English; Hylograph.Interpreter.Mermaid; Hylograph.Interpreter.MetaAST; Hylograph.Interpreter.SemiQuine; Hylograph.Interpreter.SemiQuine.TreeToCode; Hylograph.Interpreter.SemiQuine.Types; Hylograph.Render; Hylograph.Scale; Hylograph.Scale.FP; Hylograph.Shape.Arc; Hylograph.Shape.Pie; Hylograph.Shape.Polygon; Hylograph.Tooltip; Hylograph.Transform; Hylograph.TreeDSL; Hylograph.TreeDSL.ShapeTree; Hylograph.Unified; Hylograph.Unified.Attribute; Hylograph.Unified.DataDSL; Hylograph.Unified.Display; Hylograph.Unified.Examples; Hylograph.Unified.Join; Hylograph.Unified.Sugar