Scales#

class leather.Scale#

Bases: object

Base class for various kinds of scale objects.

classmethod infer(layers, dimension, data_type)#

Infer’s an appropriate default scale for a given sequence of Series.

Parameters:

  • chart_series – A sequence of Series instances

  • dimension – The dimension, X or Y of the data to infer for.

  • data_type – The type of data contained in the series dimension.

contains(v)#

Return True if a given value is contained within this scale’s displayed domain.

project(value, range_min, range_max)#

Project a value in this scale’s domain to a target range.

project_interval(value, range_min, range_max)#

Project a value in this scale’s domain to an interval in the target range. This is used for places Bars and Columns.

ticks()#

Generate a series of ticks for this scale.

format_tick(value, i, count)#

Format ticks for display.

This method is used as a default which will be ignored if the user provides a custom tick formatter to the axis.

class leather.Linear(domain_min, domain_max)#

Bases: Scale

A scale that linearly maps values from a domain to a range.

Parameters:

  • domain_min – The minimum value of the input domain.

  • domain_max – The maximum value of the input domain.

contains(v)#

Return True if a given value is contained within this scale’s domain.

project(value, range_min, range_max)#

Project a value in this scale’s domain to a target range.

project_interval(value, range_min, range_max)#

Project a value in this scale’s domain to an interval in the target range. This is used for places Bars and Columns.

ticks()#

Generate a series of ticks for this scale.

class leather.Ordinal(domain)#

Bases: Scale

A scale that maps individual values (e.g. strings) to a range.

contains(v)#

Return True if a given value is contained within this scale’s displayed domain.

project(value, range_min, range_max)#

Project a value in this scale’s domain to a target range.

project_interval(value, range_min, range_max)#

Project a value in this scale’s domain to an interval in the target range. This is used for places Bars and Columns.

ticks()#

Generate a series of ticks for this scale.

class leather.Temporal(domain_min, domain_max)#

Bases: Scale

A scale that linearly maps date/datetime values from a domain to a range.

Parameters:

  • domain_min – The minimum date/datetime of the input domain.

  • domain_max – The maximum date/datetime of the input domain.

contains(v)#

Return True if a given value is contained within this scale’s domain.

project(value, range_min, range_max)#

Project a value in this scale’s domain to a target range.

project_interval(value, range_min, range_max)#

Project a value in this scale’s domain to an interval in the target range. This is used for places Bars and Columns.

ticks()#

Generate a series of ticks for this scale.

format_tick(value, i, count)#

Format ticks for display.

This method is used as a default which will be ignored if the user provides a custom tick formatter to the axis.