IndexTranslator¶

class qf_lib.plotting.helpers.index_translator.IndexTranslator(labels_to_locations_dict: Mapping[str, numbers.Number] = None)[source]¶

Bases: object

Object which automatically translates label-indexed data into number-indexed data.

Parameters: labels_to_locations_dict (Mapping[str, Number]) – Contains a mapping from labels to numbers (used as index values for plotting). Must have unique keys and unique values.

Methods

`inv_translate`(translated_values, …)	Translates numeric coordinate into label.
`setup_ticks_and_labels`(chart)	Setups ticks’ locations and labels in the given chart if it used IndexTranslator.
`translate`(values, Sequence[str]])	Translates label into numeric coordinate.

inv_translate(translated_values: Union[numbers.Number, Sequence[numbers.Number]]) → List[str][source]¶

Translates numeric coordinate into label. Requirement: the Translator must be familiar with mapping the label into numeric coordinate (either the translate must have been called or the labels_to_locations_dict must contain a proper entry).

Parameters: translated_values – numeric values to be changed into labels (e.g. [0.0, 1.0, 2.0])
Returns: labels corresponding to numeric values
Return type: labels

classmethod setup_ticks_and_labels(chart: Chart)[source]¶: Setups ticks’ locations and labels in the given chart if it used IndexTranslator.

translate(values: Union[str, Sequence[str]]) → List[numbers.Number][source]¶

Translates label into numeric coordinate. If the translation is done for the first time for this value it may modify the state of the translator (it may introduce a new translation).

Parameters: values – values to be translated (e.g. [“SPY”, “GOOGL”])
Returns: value translated into numeric coordinate
Return type: translated values