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vtkThreshold

Section: Visualization Toolkit Graphics Classes

# Usage

vtkThreshold is a filter that extracts cells from any dataset type that satisfy a threshold criterion. A cell satisfies the criterion if the scalar value of (every or any) point satisfies the criterion. The criterion can take three forms: 1) greater than a particular value; 2) less than a particular value; or 3) between two values. The output of this filter is an unstructured grid.

Note that scalar values are available from the point and cell attribute data. By default, point data is used to obtain scalars, but you can control this behavior. See the AttributeMode ivar below.

By default only the first scalar value is used in the decision. Use the ComponentMode and SelectedComponent ivars to control this behavior.

To create an instance of class vtkThreshold, simply invoke its constructor as follows

      obj = vtkThreshold

# Methods

The class vtkThreshold has several methods that can be used. They are listed below. Note that the documentation is translated automatically from the VTK sources, and may not be completely intelligible. When in doubt, consult the VTK website. In the methods listed below, `obj` is an instance of the vtkThreshold class.

- `string = obj.GetClassName ()`
- `int = obj.IsA (string name)`
- `vtkThreshold = obj.NewInstance ()`
- `vtkThreshold = obj.SafeDownCast (vtkObject o)`
- `obj.ThresholdByLower (double lower)` - Criterion is cells whose scalars are less or equal to lower threshold.
- `obj.ThresholdByUpper (double upper)` - Criterion is cells whose scalars are greater or equal to upper threshold.
- `obj.ThresholdBetween (double lower, double upper)` - Criterion is cells whose scalars are between lower and upper thresholds (inclusive of the end values).
- `double = obj.GetUpperThreshold ()` - Get the Upper and Lower thresholds.
- `double = obj.GetLowerThreshold ()` - Get the Upper and Lower thresholds.
- `obj.SetAttributeMode (int )` - Control how the filter works with scalar point data and cell attribute data. By default (AttributeModeToDefault), the filter will use point data, and if no point data is available, then cell data is used. Alternatively you can explicitly set the filter to use point data (AttributeModeToUsePointData) or cell data (AttributeModeToUseCellData).
- `int = obj.GetAttributeMode ()` - Control how the filter works with scalar point data and cell attribute data. By default (AttributeModeToDefault), the filter will use point data, and if no point data is available, then cell data is used. Alternatively you can explicitly set the filter to use point data (AttributeModeToUsePointData) or cell data (AttributeModeToUseCellData).
- `obj.SetAttributeModeToDefault ()` - Control how the filter works with scalar point data and cell attribute data. By default (AttributeModeToDefault), the filter will use point data, and if no point data is available, then cell data is used. Alternatively you can explicitly set the filter to use point data (AttributeModeToUsePointData) or cell data (AttributeModeToUseCellData).
- `obj.SetAttributeModeToUsePointData ()` - Control how the filter works with scalar point data and cell attribute data. By default (AttributeModeToDefault), the filter will use point data, and if no point data is available, then cell data is used. Alternatively you can explicitly set the filter to use point data (AttributeModeToUsePointData) or cell data (AttributeModeToUseCellData).
- `obj.SetAttributeModeToUseCellData ()` - Control how the filter works with scalar point data and cell attribute data. By default (AttributeModeToDefault), the filter will use point data, and if no point data is available, then cell data is used. Alternatively you can explicitly set the filter to use point data (AttributeModeToUsePointData) or cell data (AttributeModeToUseCellData).
- `string = obj.GetAttributeModeAsString ()` - Control how the filter works with scalar point data and cell attribute data. By default (AttributeModeToDefault), the filter will use point data, and if no point data is available, then cell data is used. Alternatively you can explicitly set the filter to use point data (AttributeModeToUsePointData) or cell data (AttributeModeToUseCellData).
- `obj.SetComponentMode (int )` - Control how the decision of in / out is made with multi-component data. The choices are to use the selected component (specified in the SelectedComponent ivar), or to look at all components. When looking at all components, the evaluation can pass if all the components satisfy the rule (UseAll) or if any satisfy is (UseAny). The default value is UseSelected.
- `int = obj.GetComponentModeMinValue ()` - Control how the decision of in / out is made with multi-component data. The choices are to use the selected component (specified in the SelectedComponent ivar), or to look at all components. When looking at all components, the evaluation can pass if all the components satisfy the rule (UseAll) or if any satisfy is (UseAny). The default value is UseSelected.
- `int = obj.GetComponentModeMaxValue ()` - Control how the decision of in / out is made with multi-component data. The choices are to use the selected component (specified in the SelectedComponent ivar), or to look at all components. When looking at all components, the evaluation can pass if all the components satisfy the rule (UseAll) or if any satisfy is (UseAny). The default value is UseSelected.
- `int = obj.GetComponentMode ()` - Control how the decision of in / out is made with multi-component data. The choices are to use the selected component (specified in the SelectedComponent ivar), or to look at all components. When looking at all components, the evaluation can pass if all the components satisfy the rule (UseAll) or if any satisfy is (UseAny). The default value is UseSelected.
- `obj.SetComponentModeToUseSelected ()` - Control how the decision of in / out is made with multi-component data. The choices are to use the selected component (specified in the SelectedComponent ivar), or to look at all components. When looking at all components, the evaluation can pass if all the components satisfy the rule (UseAll) or if any satisfy is (UseAny). The default value is UseSelected.
- `obj.SetComponentModeToUseAll ()` - Control how the decision of in / out is made with multi-component data. The choices are to use the selected component (specified in the SelectedComponent ivar), or to look at all components. When looking at all components, the evaluation can pass if all the components satisfy the rule (UseAll) or if any satisfy is (UseAny). The default value is UseSelected.
- `obj.SetComponentModeToUseAny ()` - Control how the decision of in / out is made with multi-component data. The choices are to use the selected component (specified in the SelectedComponent ivar), or to look at all components. When looking at all components, the evaluation can pass if all the components satisfy the rule (UseAll) or if any satisfy is (UseAny). The default value is UseSelected.
- `string = obj.GetComponentModeAsString ()` - Control how the decision of in / out is made with multi-component data. The choices are to use the selected component (specified in the SelectedComponent ivar), or to look at all components. When looking at all components, the evaluation can pass if all the components satisfy the rule (UseAll) or if any satisfy is (UseAny). The default value is UseSelected.
- `obj.SetSelectedComponent (int )` - When the component mode is UseSelected, this ivar indicated the selected component. The default value is 0.
- `int = obj.GetSelectedComponentMinValue ()` - When the component mode is UseSelected, this ivar indicated the selected component. The default value is 0.
- `int = obj.GetSelectedComponentMaxValue ()` - When the component mode is UseSelected, this ivar indicated the selected component. The default value is 0.
- `int = obj.GetSelectedComponent ()` - When the component mode is UseSelected, this ivar indicated the selected component. The default value is 0.
- `obj.SetAllScalars (int )` - If using scalars from point data, all scalars for all points in a cell must satisfy the threshold criterion if AllScalars is set. Otherwise, just a single scalar value satisfying the threshold criterion enables will extract the cell.
- `int = obj.GetAllScalars ()` - If using scalars from point data, all scalars for all points in a cell must satisfy the threshold criterion if AllScalars is set. Otherwise, just a single scalar value satisfying the threshold criterion enables will extract the cell.
- `obj.AllScalarsOn ()` - If using scalars from point data, all scalars for all points in a cell must satisfy the threshold criterion if AllScalars is set. Otherwise, just a single scalar value satisfying the threshold criterion enables will extract the cell.
- `obj.AllScalarsOff ()` - If using scalars from point data, all scalars for all points in a cell must satisfy the threshold criterion if AllScalars is set. Otherwise, just a single scalar value satisfying the threshold criterion enables will extract the cell.
- `obj.SetPointsDataTypeToDouble ()` - Set the data type of the output points (See the data types defined in vtkType.h). The default data type is float.
- `obj.SetPointsDataTypeToFloat ()` - Set the data type of the output points (See the data types defined in vtkType.h). The default data type is float.
- `obj.SetPointsDataType (int )` - Set the data type of the output points (See the data types defined in vtkType.h). The default data type is float.
- `int = obj.GetPointsDataType ()` - Set the data type of the output points (See the data types defined in vtkType.h). The default data type is float.