Scales

`bqscales.Scale`

Bases: Widget

The base scale class.

Scale objects represent a mapping between data (the domain) and a visual quantity (The range).

ATTRIBUTE	DESCRIPTION
`scale_types`	A registry of existing scale types. TYPE: `dict (class-level attribute)`
`domain_class`	traitlet type used to validate values in of the domain of the scale. TYPE: `type (default: Float)`
`reverse`	whether the scale should be reversed. TYPE: `bool (default: False)`
`allow_padding`	indicates whether figures are allowed to add data padding to this scale or not. TYPE: `bool (default: True)`
`precedence`	attribute used to determine which scale takes precedence in cases when two or more scales have the same rtype and dtype. TYPE: `int (class-level attribute)`

`bqscales.LinearScale`

Bases: Scale

A linear scale.

An affine mapping from a numerical domain to a numerical range.

ATTRIBUTE	DESCRIPTION
`min`	if not None, min is the minimal value of the domain TYPE: `float or None (default: None)`
`max`	if not None, max is the maximal value of the domain TYPE: `float or None (default: None)`
`rtype`	This attribute should not be modified. The range type of a linear scale is numerical. TYPE: `string (class-level attribute)`
`dtype`	the associated data type / domain type TYPE: `type (class-level attribute)`
`precedence`	attribute used to determine which scale takes precedence in cases when two or more scales have the same rtype and dtype. default_value is 2 because for the same range and domain types, LinearScale should take precedence. TYPE: `int (class-level attribute, default_value=2)`
`stabilized`	if set to False, the domain of the scale is tied to the data range if set to True, the domain of the scale is updated only when the data range is beyond certain thresholds, given by the attributes mid_range and min_range. TYPE: `bool (default: False)`
`mid_range`	Proportion of the range that is spanned initially. Used only if stabilized is True. TYPE: `float (default: 0.8)`
`min_range`	Minimum proportion of the range that should be spanned by the data. If the data span falls beneath that level, the scale is reset. min_range must be <= mid_range. Used only if stabilized is True. TYPE: `float (default: 0.6)`

`bqscales.LogScale`

Bases: Scale

A log scale.

A logarithmic mapping from a numerical domain to a numerical range.

ATTRIBUTE	DESCRIPTION
`min`	if not None, min is the minimal value of the domain TYPE: `float or None (default: None)`
`max`	if not None, max is the maximal value of the domain TYPE: `float or None (default: None)`
`rtype`	This attribute should not be modified by the user. The range type of a linear scale is numerical. TYPE: `string (class-level attribute)`
`dtype`	the associated data type / domain type TYPE: `type (class-level attribute)`

`bqscales.DateScale`

Bases: Scale

A date scale, with customizable formatting.

An affine mapping from dates to a numerical range.

ATTRIBUTE	DESCRIPTION
`min`	if not None, min is the minimal value of the domain TYPE: `Date or None (default: None)`
`max`	if not None, max is the maximal value of the domain TYPE: `Date (default: None)`
`domain_class`	traitlet type used to validate values in of the domain of the scale. TYPE: `type (default: Date)`
`rtype`	This attribute should not be modified by the user. The range type of a linear scale is numerical. TYPE: `string (class-level attribute)`
`dtype`	the associated data type / domain type TYPE: `type (class-level attribute)`

`bqscales.OrdinalScale`

Bases: Scale

An ordinal scale.

A mapping from a discrete set of values to a numerical range.

ATTRIBUTE	DESCRIPTION
`domain`	The discrete values mapped by the ordinal scale TYPE: `list (default: [])`
`rtype`	This attribute should not be modified by the user. The range type of a linear scale is numerical. TYPE: `string (class-level attribute)`
`dtype`	the associated data type / domain type TYPE: `type (class-level attribute)`

`bqscales.ColorScale`

Bases: Scale

A color scale.

A mapping from numbers to colors. The relation is affine by part.

ATTRIBUTE	DESCRIPTION
`scale_type`	scale type TYPE: `{linear}`
`colors`	list of colors TYPE: `list of colors (default: [])`
`min`	if not None, min is the minimal value of the domain TYPE: `float or None (default: None)`
`max`	if not None, max is the maximal value of the domain TYPE: `float or None (default: None)`
`mid`	if not None, mid is the value corresponding to the mid color. TYPE: `float or None (default: None)`
`scheme`	Colorbrewer color scheme of the color scale. TYPE: `string (default: 'RdYlGn')`
`extrapolation`	How to extrapolate values outside the [min, max] domain. TYPE: `{'constant', 'linear'} (default: 'constant')`
`rtype`	The range type of a color scale is 'Color'. This should not be modified. TYPE: `string (class-level attribute)`
`dtype`	the associated data type / domain type TYPE: `type (class-level attribute)`

`bqscales.DateColorScale`

Bases: ColorScale

A date color scale.

A mapping from dates to a numerical domain.

ATTRIBUTE	DESCRIPTION
`min`	if not None, min is the minimal value of the domain TYPE: `Date or None (default: None)`
`max`	if not None, max is the maximal value of the domain TYPE: `Date or None (default: None)`
`mid`	if not None, mid is the value corresponding to the mid color. TYPE: `Date or None (default: None)`
`rtype`	This attribute should not be modified by the user. The range type of a color scale is 'Color'. TYPE: `string (class-level attribute)`
`dtype`	the associated data type / domain type TYPE: `type (class-level attribute)`

`bqscales.OrdinalColorScale`

Bases: ColorScale

An ordinal color scale.

A mapping from a discrete set of values to colors.

ATTRIBUTE	DESCRIPTION
`domain`	The discrete values mapped by the ordinal scales. TYPE: `list (default: [])`
`rtype`	This attribute should not be modified by the user. The range type of a color scale is 'color'. TYPE: `string (class-level attribute)`
`dtype`	the associated data type / domain type TYPE: `type (class-level attribute)`

`bqscales.GeoScale`

Bases: Scale

The base projection scale class for Map marks.

The GeoScale represents a mapping between topographic data and a 2d visual representation.

`bqscales.Orthographic`

Bases: GeoScale

A perspective projection that depicts a hemisphere as it appears from outer space.

The projection is neither equal-area nor conformal.

ATTRIBUTE	DESCRIPTION
`scale_factor`	Specifies the scale value for the projection TYPE: `float (default: 145)`
`center`	Specifies the longitude and latitude where the map is centered. TYPE: `tuple (default: (0, 60))`
`rotate`	Degree of rotation in each axis. TYPE: `tuple (default: (96, 0))`
`clip_angle`	Specifies the clipping circle radius to the specified angle in degrees. TYPE: `float (default: 90.)`
`precision`	Specifies the threshold for the projections adaptive resampling to the specified value in pixels. TYPE: `float (default: 0.1)`

`bqscales.Mercator`

Bases: GeoScale

A geographical projection scale commonly used for world maps.

The Mercator projection is a cylindrical map projection which ensures that any course of constant bearing is a straight line.

ATTRIBUTE	DESCRIPTION
`scale_factor`	Specifies the scale value for the projection TYPE: `float (default: 190)`
`center`	Specifies the longitude and latitude where the map is centered. TYPE: `tuple (default: (0, 60))`
`rotate`	Degree of rotation in each axis. TYPE: `tuple (default: (0, 0))`
`rtype`	This attribute should not be modified. The range type of a geo scale is a tuple. TYPE: `(Number, Number) (class-level attribute)`
`dtype`	the associated data type / domain type TYPE: `type (class-level attribute)`

`bqscales.Albers`

Bases: GeoScale

A geographical scale which is an alias for a conic equal area projection.

The Albers projection is a conic equal area map. It does not preserve scale or shape, though it is recommended for chloropleths since it preserves the relative areas of geographic features. Default values are US-centric.

ATTRIBUTE	DESCRIPTION
`scale_factor`	Specifies the scale value for the projection TYPE: `float (default: 250)`
`rotate`	Degree of rotation in each axis. TYPE: `tuple (default: (96, 0))`
`parallels`	Sets the two parallels for the conic projection. TYPE: `tuple (default: (29.5, 45.5))`
`center`	Specifies the longitude and latitude where the map is centered. TYPE: `tuple (default: (0, 60))`
`precision`	Specifies the threshold for the projections adaptive resampling to the specified value in pixels. TYPE: `float (default: 0.1)`
`rtype`	This attribute should not be modified. The range type of a geo scale is a tuple. TYPE: `(Number, Number) (class-level attribute)`
`dtype`	the associated data type / domain type TYPE: `type (class-level attribute)`

`bqscales.AlbersUSA`

Bases: GeoScale

A composite projection of four Albers projections meant specifically for the United States.

ATTRIBUTE	DESCRIPTION
`scale_factor`	Specifies the scale value for the projection TYPE: `float (default: 1200)`
`translate`	TYPE: `tuple (default: (600, 490))`
`rtype`	This attribute should not be modified. The range type of a geo scale is a tuple. TYPE: `(Number, Number) (class-level attribute)`
`dtype`	the associated data type / domain type TYPE: `type (class-level attribute)`

`bqscales.Gnomonic`

Bases: GeoScale

A perspective projection which displays great circles as straight lines.

The projection is neither equal-area nor conformal.

ATTRIBUTE	DESCRIPTION
`scale_factor`	Specifies the scale value for the projection TYPE: `float (default: 145)`
`center`	Specifies the longitude and latitude where the map is centered. TYPE: `tuple (default: (0, 60))`
`precision`	Specifies the threshold for the projections adaptive resampling to the specified value in pixels. TYPE: `float (default: 0.1)`
`clip_angle`	Specifies the clipping circle radius to the specified angle in degrees. TYPE: `float (default: 89.999)`

`bqscales.Stereographic`

Bases: GeoScale

A perspective projection that uses a bijective and smooth map at every point except the projection point.

The projection is not an equal-area projection but it is conformal.

ATTRIBUTE	DESCRIPTION
`scale_factor`	Specifies the scale value for the projection TYPE: `float (default: 250)`
`rotate`	Degree of rotation in each axis. TYPE: `tuple (default: (96, 0))`
`center`	Specifies the longitude and latitude where the map is centered. TYPE: `tuple (default: (0, 60))`
`precision`	Specifies the threshold for the projections adaptive resampling to the specified value in pixels. TYPE: `float (default: 0.1)`
`clip_angle`	Specifies the clipping circle radius to the specified angle in degrees. TYPE: `float (default: 90.)`

`bqscales.EquiRectangular`

Bases: GeoScale

An elementary projection that uses the identity function.

The projection is neither equal-area nor conformal.

ATTRIBUTE	DESCRIPTION
`scale_factor`	Specifies the scale value for the projection TYPE: `float (default: 145)`
`center`	Specifies the longitude and latitude where the map is centered. TYPE: `tuple (default: (0, 60))`