The type of scale. Vega-Lite supports the following categories of scale types:

1)Continuous Scales – mapping continuous domains to continuous output ranges ("linear","pow","sqrt","symlog","log","time","utc".

2)Discrete Scales – mapping discrete domains to discrete ("ordinal") or continuous ("band" and"point") output ranges.

3)Discretizing Scales – mapping continuous domains to discrete output ranges"bin-ordinal","quantile","quantize" and"threshold".

Default value: please see thescale type table.

Customized domain values in the form of constant values or dynamic values driven by a parameter.

1) Constantdomain forquantitative fields can take one of the following forms:

• A two-element array with minimum and maximum values. To create a diverging scale, this two-element array can be combined with thedomainMid property.
• An array with more than two entries, forPiecewise quantitative scales.
• A string value"unaggregated", if the input field is aggregated, to indicate that the domain should include the raw data values prior to the aggregation.

2) Constantdomain fortemporal fields can be a two-element array with minimum and maximum values, in the form of either timestamps or theDateTime definition objects.

3) Constantdomain forordinal andnominal fields can be an array that lists valid input values.

4) To combine (union) specified constant domain with the field’s values,domain can be an object with aunionWith property that specify constant domain to be combined. For example,domain: {unionWith: [0, 100]} for a quantitative scale means that the scale domain always includes[0, 100], but will include other values in the fields beyond[0, 100].

5) Domain can also takes an object defining a field or encoding of a parameter thatinteractively determines the scale domain.

Sets the maximum value in the scale domain, overriding thedomain property. This property is only intended for use with scales having continuous domains.

Sets the minimum value in the scale domain, overriding the domain property. This property is only intended for use with scales having continuous domains.

Inserts a single mid-point value into a two-element domain. The mid-point value must lie between the domain minimum and maximum values. This property can be useful for setting a midpoint fordiverging color scales. The domainMid property is only intended for use with scales supporting continuous, piecewise domains.

An expression for an array of raw values that, if non-null, directly overrides thedomain property. This is useful for supporting interactions such as panning or zooming a scale. The scale may be initially determined using a data-driven domain, then modified in response to user input by setting the rawDomain value.

The range of the scale. One of:

• A string indicating apre-defined named scale range (e.g., example,"symbol", or"diverging").

• Forcontinuous scales, two-element array indicating minimum and maximum values, or an array with more than two entries for specifying apiecewise scale.

• Fordiscrete anddiscretizing scales, an array of desired output values or an object with afield property representing the range values. For example, if a fieldcolor contains CSS color names, we can setrange to{field: "color"}.

Notes:

1) For color scales you can also specify a colorscheme instead ofrange.

2) Any directly specifiedrange forx andy channels will be ignored. Range can be customized via the view’s correspondingsize (width andheight).

Sets the minimum value in the scale range, overriding therange property or the default range. This property is only intended for use with scales having continuous ranges.

Sets the maximum value in the scale range, overriding therange property or the default range. This property is only intended for use with scales having continuous ranges.

A string indicating a colorscheme name (e.g.,"category10" or"blues") or ascheme parameter object.

Discrete color schemes may be used withdiscrete ordiscretizing scales. Continuous color schemes are intended for use with color scales.

To set a custom scheme, instead set the list of valuesas the scale range.

For the full list of supported schemes, please refer to theVega Scheme reference.

Required. A color scheme name for ordinal scales (e.g.,"category10" or"blues").

For the full list of supported schemes, please refer to theVega Scheme reference.

The extent of the color range to use. For example[0.2, 1] will rescale the color scheme such that color values in the range[0, 0.2) are excluded from the scheme.

The number of colors to use in the scheme. This can be useful for scale types such as"quantize", which use the length of the scale range to determine the number of discrete bins for the scale domain.

If true, reverses the order of the scale range.Default value:false.

Iftrue, rounds numeric output values to integers. This can be helpful for snapping to the pixel grid.

Default value:false.

Iftrue, values that exceed the data domain are clamped to either the minimum or maximum range value

Default value: derived from thescale config’sclamp (true by default).

The interpolation method for range values. By default, a general interpolator for numbers, dates, strings and colors (in HCL space) is used. For color ranges, this property allows interpolation in alternative color spaces. Legal values includergb,hsl,hsl-long,lab,hcl,hcl-long,cubehelix andcubehelix-long (‘-long’ variants use longer paths in polar coordinate spaces). If object-valued, this property accepts an object with a string-valuedtype property and an optional numericgamma property applicable to rgb and cubehelix interpolators. For more, see thed3-interpolate documentation.

• Default value:hcl

Extending the domain so that it starts and ends on nice round values. This method typically modifies the scale’s domain, and may only extend the bounds to the nearest round value. Nicing is useful if the domain is computed from data and may be irregular. For example, for a domain of[0.201479…, 0.996679…], a nice domain might be[0.2, 1.0].

For quantitative scales such as linear,nice can be either a boolean flag or a number. Ifnice is a number, it will represent a desired tick count. This allows greater control over the step size used to extend the bounds, guaranteeing that the returned ticks will exactly cover the domain.

For temporal fields with time and utc scales, thenice value can be a string indicating the desired time interval. Legal values are"millisecond","second","minute","hour","day","week","month", and"year". Alternatively,time andutc scales can accept an object-valued interval specifier of the form{"interval": "month", "step": 3}, which includes a desired number of interval steps. Here, the domain would snap to quarter (Jan, Apr, Jul, Oct) boundaries.

Default value:true for unbinnedquantitative fields without explicit domain bounds;false otherwise.

Forcontinuous scales, expands the scale domain to accommodate the specified number of pixels on each of the scale range. The scale range must represent pixels for this parameter to function as intended. Padding adjustment is performed prior to all other adjustments, including the effects of the zero, nice, domainMin, and domainMax properties.

Forband scales, shortcut for settingpaddingInner andpaddingOuter to the same value.

Forpoint scales, alias forpaddingOuter.

Default value: Forcontinuous scales, derived from thescale config’scontinuousPadding. Forband and point scales, seepaddingInner andpaddingOuter. By default, Vega-Lite sets padding such thatwidth/height = number of unique values * step.

Iftrue, ensures that a zero baseline value is included in the scale domain.

Default value:true for x and y channels if the quantitative field is not binned and no customdomain is provided;false otherwise.

Note: Log, time, and utc scales do not supportzero.

The exponent of thepow scale.

The logarithm base of thelog scale (default10).

A constant determining the slope of the symlog function around zero. Only used forsymlog scales.

Default value:1

The alignment of the steps within the scale range.

This value must lie in the range[0,1]. A value of0.5 indicates that the steps should be centered within the range. A value of0 or1 may be used to shift the bands to one side, say to position them adjacent to an axis.

Default value:0.5

Forcontinuous scales, expands the scale domain to accommodate the specified number of pixels on each of the scale range. The scale range must represent pixels for this parameter to function as intended. Padding adjustment is performed prior to all other adjustments, including the effects of the zero, nice, domainMin, and domainMax properties.

Forband scales, shortcut for settingpaddingInner andpaddingOuter to the same value.

Forpoint scales, alias forpaddingOuter.

Default value: Forcontinuous scales, derived from thescale config’scontinuousPadding. Forband and point scales, seepaddingInner andpaddingOuter. By default, Vega-Lite sets padding such thatwidth/height = number of unique values * step.

The inner padding (spacing) within each band step of band scales, as a fraction of the step size. This value must lie in the range [0,1].

For point scale, this property is invalid as point scales do not have internal band widths (only step sizes between bands).

Default value: derived from thescale config’sbandPaddingInner.

The outer padding (spacing) at the ends of the range of band and point scales, as a fraction of the step size. This value must lie in the range [0,1].

Default value: derived from thescale config’sbandPaddingOuter for band scales andpointPadding for point scales. By default, Vega-Lite sets outer padding such thatwidth/height = number of unique values * step.

Bin boundaries can be provided to scales as either an explicit array of bin boundaries or as a bin specification object. The legal values are:

• Anarray literal of bin boundary values. For example,[0, 5, 10, 15, 20]. The array must include both starting and ending boundaries. The previous example uses five values to indicate a total of four bin intervals: [0-5), [5-10), [10-15), [15-20]. Array literals may include signal references as elements.
• Abin specification object that indicates the binstep size, and optionally thestart andstop boundaries.
• An array of bin boundaries over the scale domain. If provided, axes and legends will use the bin boundaries to inform the choice of tick marks and text labels.

Extending the domain so that it starts and ends on nice round values. This method typically modifies the scale’s domain, and may only extend the bounds to the nearest round value. Nicing is useful if the domain is computed from data and may be irregular. For example, for a domain of[0.201479…, 0.996679…], a nice domain might be[0.2, 1.0].

For quantitative scales such as linear,nice can be either a boolean flag or a number. Ifnice is a number, it will represent a desired tick count. This allows greater control over the step size used to extend the bounds, guaranteeing that the returned ticks will exactly cover the domain.

For temporal fields with time and utc scales, thenice value can be a string indicating the desired time interval. Legal values are"millisecond","second","minute","hour","day","week","month", and"year". Alternatively,time andutc scales can accept an object-valued interval specifier of the form{"interval": "month", "step": 3}, which includes a desired number of interval steps. Here, the domain would snap to quarter (Jan, Apr, Jul, Oct) boundaries.

Default value:true for unbinnedquantitative fields without explicit domain bounds;false otherwise.

Iftrue, ensures that a zero baseline value is included in the scale domain.

Default value:true for x and y channels if the quantitative field is not binned and no customdomain is provided;false otherwise.

Note: Log, time, and utc scales do not supportzero.

Default inner padding forx andy band scales.

Default value:

• nestedOffsetPaddingInner for x/y scales with nested x/y offset scales.
• barBandPaddingInner for bar marks (0.1 by default)
• rectBandPaddingInner for rect and other marks (0 by default)

Default inner padding forx andy band-ordinal scales of"bar" marks.

Default value:0.1

Default inner padding forx andy band-ordinal scales of"rect" marks.

Default value:0

Default inner padding forx andy band scales with nestedxOffset andyOffset encoding.

Default value:0.2

Default padding inner for xOffset/yOffset’s band scales.

Default Value:0

Default outer padding forx andy band scales.

Default value:paddingInner/2 (which makeswidth/height = number of unique values * step)

Default outer padding forx andy band scales with nestedxOffset andyOffset encoding.

Default value:0.2

Default padding outer for xOffset/yOffset’s band scales.

Default Value:0

Default padding for continuous x/y scales.

Default: The bar width for continuous x-scale of a vertical bar and continuous y-scale of a horizontal bar.;0 otherwise.

Default outer padding forx andy point-ordinal scales.

Default value:0.5 (which makeswidth/height = number of unique values * step)

The default max value for mapping quantitative fields to bar’s size/bandSize.

If undefined (default), we will use the axis’s size (width or height) - 1.

The default min value for mapping quantitative fields to bar and tick’s size/bandSize scale.

Default value:2

The default max value for mapping quantitative fields to text’s size/fontSize scale.

Default value:40

The default min value for mapping quantitative fields to text’s size/fontSize scale.

Default value:8

Default max opacity for mapping a field to opacity.

Default value:0.8

Default minimum opacity for mapping a field to opacity.

Default value:0.3

Default max value for point size scale.

Default minimum value for point size scale.

Default value:9

Default max strokeWidth for the scale of strokeWidth for rule and line marks and of size for trail marks.

Default value:4

Default minimum strokeWidth for the scale of strokeWidth for rule and line marks and of size for trail marks.

Default value:1

An object that defines scale outputs per channel for invalid values (nulls and NaNs on a continuous scale).

• The keys in this object are the scale channels.
• The values is either"zero-or-min" (use zero if the scale includes zero or min value otherwise) or a value definition{value: ...}.

Example: Setting thisconfig.scale.invalid property to{color: {value: '#aaa'}} will make the visualization color all invalid values with ‘#aaa’.

Seehttps://vega.github.io/vega-lite/docs/invalid-data.html for more details.

If true, values that exceed the data domain are clamped to either the minimum or maximum range value

If true, rounds numeric output values to integers. This can be helpful for snapping to the pixel grid. (Only available forx,y, andsize scales.)

Reverse x-scale by default (useful for right-to-left charts).

Use the source data range before aggregation as scale domain instead of aggregated data for aggregate axis.

This is equivalent to settingdomain to"unaggregate" for aggregatedquantitative fields by default.

This property only works with aggregate functions that produce values within the raw data domain ("mean","average","median","q1","q3","min","max"). For other aggregations that produce values outside of the raw data domain (e.g."count","sum"), this property is ignored.

Default value:false

Defaultscale.zero forcontinuous scales except for (1) x/y-scales of non-ranged bar or area charts and (2) size scales.

Default value:true

Defaultcolor scheme for categorical data.

Defaultcolor scheme for diverging quantitative ramps.

Defaultcolor scheme for quantitative heatmaps.

Defaultcolor scheme for rank-ordered data.

Defaultcolor scheme for sequential quantitative ramps.

Array ofsymbol names or paths for the default shape palette.