Subgroup: other
Class: QgsSizeScaleTransformer¶
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class
qgis.core.
QgsSizeScaleTransformer
¶ Bases:
qgis._core.QgsPropertyTransformer
QgsPropertyTransformer subclass for scaling a value into a size according to various scaling methods.
New in version 3.0: Methods
clone
create
Factory method for creating a new property transformer of the specified type. curveTransform
Returns the curve transform applied to input values before they are transformed by the individual transform subclasses. exponent
Returns the exponent for an exponential expression. fromExpression
Attempts to parse an expression into a corresponding QgsSizeScaleTransformer. loadVariant
maxSize
Returns the maximum calculated size. maxValue
Returns the maximum value expected by the transformer. minSize
Returns the minimum calculated size. minValue
Returns the minimum value expected by the transformer. nullSize
Returns the size value when an expression evaluates to NULL. setCurveTransform
Sets a curve transform to apply to input values before they are transformed by the individual transform subclasses. setExponent
Sets the exponent for an exponential expression. setMaxSize
Sets the maximum calculated size. setMaxValue
Sets the maximum value expected by the transformer. setMinSize
Sets the minimum calculated size. setMinValue
Sets the minimum value expected by the transformer. setNullSize
Sets the size value for when an expression evaluates to NULL. setType
Sets the size transformer’s scaling type (the method used to calculate the size from a value). size
Calculates the size corresponding to a specific value. toExpression
toVariant
transform
transformNumeric
transformerType
type
Returns the size transformer’s scaling type (the method used to calculate the size from a value). Attributes
Area
ColorRampTransformer
Exponential
Flannery
GenericNumericTransformer
Linear
SizeScaleTransformer
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Area
= 1¶
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Exponential
= 3¶
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Flannery
= 2¶
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Linear
= 0¶
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class
ScaleType
¶ Bases:
int
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clone
(self) → QgsSizeScaleTransformer¶
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exponent
(self) → float¶ Returns the exponent for an exponential expression.
See also
See also
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fromExpression
(expression: str) → Tuple[QgsSizeScaleTransformer, str, str]¶ Attempts to parse an expression into a corresponding QgsSizeScaleTransformer.
Parameters: - expression – expression to parse
- baseExpression – will be set to the component of the source expression which
is used to calculate the input to the property transformer. This will be set to an empty string if a field reference is the transformer input. :param fieldName: will be set to a field name which is used to calculate the input to the property transformer. This will be set to an empty string if an expression is the transformer input.
Returns: corresponding QgsSizeScaleTransformer, or None if expression could not be parsed to a size scale transformer.
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loadVariant
(self, definition: Any) → bool¶
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minSize
(self) → float¶ Returns the minimum calculated size.
See also
See also
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nullSize
(self) → float¶ Returns the size value when an expression evaluates to NULL.
See also
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setExponent
(self, exponent: float)¶ Sets the exponent for an exponential expression.
Parameters: exponent – exponent See also
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setMaxSize
(self, size: float)¶ Sets the maximum calculated size.
Parameters: size – maximum size See also
See also
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setMinSize
(self, size: float)¶ Sets the minimum calculated size.
Parameters: size – minimum size See also
See also
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setNullSize
(self, size: float)¶ Sets the size value for when an expression evaluates to NULL.
Parameters: size – null size See also
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setType
(self, type: QgsSizeScaleTransformer.ScaleType)¶ Sets the size transformer’s scaling type (the method used to calculate the size from a value).
Parameters: type – scale type See also
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size
(self, value: float) → float¶ Calculates the size corresponding to a specific value.
Parameters: value – value to calculate size for Returns: calculated size using size scale transformer’s parameters and type
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toExpression
(self, baseExpression: str) → str¶
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toVariant
(self) → Any¶
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transform
(self, context: QgsExpressionContext, value: Any) → Any¶
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transformNumeric
()¶
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transformerType
(self) → QgsPropertyTransformer.Type¶
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