altair.RegressionTransform

class altair.RegressionTransform(on=Undefined, regression=Undefined, extent=Undefined, groupby=Undefined, method=Undefined, order=Undefined, params=Undefined, **kwds)

RegressionTransform schema wrapper

Mapping(required=[regression, on])

Attributes

onFieldName

The data field of the independent variable to use a predictor.

regressionFieldName

The data field of the dependent variable to predict.

extentList([float, float])

A [min, max] domain over the independent (x) field for the starting and ending points of the generated trend line.

groupbyList(FieldName)

The data fields to group by. If not specified, a single group containing all data objects will be used.

methodenum(‘linear’, ‘log’, ‘exp’, ‘pow’, ‘quad’, ‘poly’)

The functional form of the regression model. One of "linear", "log", "exp", "pow", "quad", or "poly".

Default value: "linear"

orderfloat

The polynomial order (number of coefficients) for the ‘poly’ method.

Default value: 3

paramsboolean

A boolean flag indicating if the transform should return the regression model parameters (one object per group), rather than trend line points. The resulting objects include a coef array of fitted coefficient values (starting with the intercept term and then including terms of increasing order) and an rSquared value (indicating the total variance explained by the model).

Default value: false

asList([FieldName, FieldName])

The output field names for the smoothed points generated by the regression transform.

Default value: The field names of the input x and y values.

__init__(self, on=Undefined, regression=Undefined, extent=Undefined, groupby=Undefined, method=Undefined, order=Undefined, params=Undefined, **kwds)

Initialize self. See help(type(self)) for accurate signature.

Methods

__init__(self[, on, regression, extent, …])	Initialize self.
copy(self[, deep, ignore])	Return a copy of the object
from_dict(dct[, validate, _wrapper_classes])	Construct class from a dictionary representation
from_json(json_string[, validate])	Instantiate the object from a valid JSON string
resolve_references([schema])	Resolve references in the context of this object’s schema or root schema.
to_dict(self[, validate, ignore, context])	Return a dictionary representation of the object
to_json(self[, validate, ignore, context, …])	Emit the JSON representation for this object as a string.
validate(instance[, schema])	Validate the instance against the class schema in the context of the rootschema.
validate_property(name, value[, schema])	Validate a property against property schema in the context of the rootschema

copy(self, deep=True, ignore=())

Return a copy of the object

Parameters

deepboolean or list, optional

If True (default) then return a deep copy of all dict, list, and SchemaBase objects within the object structure. If False, then only copy the top object. If a list or iterable, then only copy the listed attributes.

ignorelist, optional

A list of keys for which the contents should not be copied, but only stored by reference.

classmethod from_dict(dct, validate=True, _wrapper_classes=None)

Construct class from a dictionary representation

Parameters

dctdictionary

The dict from which to construct the class

validateboolean

If True (default), then validate the input against the schema.

_wrapper_classeslist (optional)

The set of SchemaBase classes to use when constructing wrappers of the dict inputs. If not specified, the result of cls._default_wrapper_classes will be used.

Returns

objSchema object

The wrapped schema

Raises

jsonschema.ValidationError :

if validate=True and dct does not conform to the schema

classmethod from_json(json_string, validate=True, **kwargs)

Instantiate the object from a valid JSON string

Parameters

json_stringstring

The string containing a valid JSON chart specification.

validateboolean

If True (default), then validate the input against the schema.

**kwargs :

Additional keyword arguments are passed to json.loads

Returns

chartChart object

The altair Chart object built from the specification.

classmethod resolve_references(schema=None)

Resolve references in the context of this object’s schema or root schema.

to_dict(self, validate=True, ignore=None, context=None)

Return a dictionary representation of the object

Parameters

validateboolean or string

If True (default), then validate the output dictionary against the schema. If “deep” then recursively validate all objects in the spec. This takes much more time, but it results in friendlier tracebacks for large objects.

ignorelist

A list of keys to ignore. This will not passed to child to_dict function calls.

contextdict (optional)

A context dictionary that will be passed to all child to_dict function calls

Returns

dctdictionary

The dictionary representation of this object

Raises

jsonschema.ValidationError :

if validate=True and the dict does not conform to the schema

to_json(self, validate=True, ignore=[], context={}, indent=2, sort_keys=True, **kwargs)

Emit the JSON representation for this object as a string.

Parameters

validateboolean or string

If True (default), then validate the output dictionary against the schema. If “deep” then recursively validate all objects in the spec. This takes much more time, but it results in friendlier tracebacks for large objects.

ignorelist

A list of keys to ignore. This will not passed to child to_dict function calls.

contextdict (optional)

A context dictionary that will be passed to all child to_dict function calls

indentinteger, default 2

the number of spaces of indentation to use

sort_keysboolean, default True

if True, sort keys in the output

**kwargs

Additional keyword arguments are passed to json.dumps()

Returns

specstring

The JSON specification of the chart object.

classmethod validate(instance, schema=None)

Validate the instance against the class schema in the context of the rootschema.

classmethod validate_property(name, value, schema=None)

Validate a property against property schema in the context of the rootschema