Section: Visualization Toolkit Filtering Classes
To create an instance of class vtkPiecewiseFunction, simply invoke its constructor as follows
obj = vtkPiecewiseFunction
obj
is an instance of the vtkPiecewiseFunction class.
string = obj.GetClassName ()
int = obj.IsA (string name)
vtkPiecewiseFunction = obj.NewInstance ()
vtkPiecewiseFunction = obj.SafeDownCast (vtkObject o)
obj.DeepCopy (vtkDataObject f)
obj.ShallowCopy (vtkDataObject f)
int = obj.GetDataObjectType ()
- Return what type of dataset this is.
int = obj.GetSize ()
- Get the number of points used to specify the function
int = obj.AddPoint (double x, double y)
- Add/Remove points to/from the function. If a duplicate point is added
then the function value is changed at that location.
Return the index of the point (0 based), or -1 on error.
int = obj.AddPoint (double x, double y, double midpoint, double sharpness)
- Add/Remove points to/from the function. If a duplicate point is added
then the function value is changed at that location.
Return the index of the point (0 based), or -1 on error.
int = obj.RemovePoint (double x)
- Add/Remove points to/from the function. If a duplicate point is added
then the function value is changed at that location.
Return the index of the point (0 based), or -1 on error.
obj.RemoveAllPoints ()
- Removes all points from the function.
obj.AddSegment (double x1, double y1, double x2, double y2)
- Add a line segment to the function. All points defined between the
two points specified are removed from the function. This is a legacy
method that does not allow the specification of the sharpness and
midpoint values for the two nodes.
double = obj.GetValue (double x)
- Returns the value of the function at the specified location using
the specified interpolation.
int = obj.GetNodeValue (int index, double val[4])
- For the node specified by index, set/get the
location (X), value (Y), midpoint, and sharpness
values at the node.
int = obj.SetNodeValue (int index, double val[4])
- For the node specified by index, set/get the
location (X), value (Y), midpoint, and sharpness
values at the node.
obj.FillFromDataPointer (int , double )
- Returns a pointer to the data stored in the table.
Fills from a pointer to data stored in a similar table. These are
legacy methods which will be maintained for compatibility - however,
note that the vtkPiecewiseFunction no longer stores the nodes
in a double array internally.
double = obj. GetRange ()
- Returns the min and max node locations of the function.
int = obj.AdjustRange (double range[2])
- Remove all points out of the new range, and make sure there is a point
at each end of that range.
Return 1 on success, 0 otherwise.
obj.GetTable (double x1, double x2, int size, float table, int stride)
- Fills in an array of function values evaluated at regular intervals.
Parameter "stride" is used to step through the output "table".
obj.GetTable (double x1, double x2, int size, double table, int stride)
- Fills in an array of function values evaluated at regular intervals.
Parameter "stride" is used to step through the output "table".
obj.BuildFunctionFromTable (double x1, double x2, int size, double table, int stride)
- Constructs a piecewise function from a table. Function range is
is set to [x1, x2], function size is set to size, and function points
are regularly spaced between x1 and x2. Parameter "stride" is
is step through the input table.
obj.SetClamping (int )
- When zero range clamping is Off, GetValue() returns 0.0 when a
value is requested outside of the points specified.
When zero range clamping is On, GetValue() returns the value at
the value at the lowest point for a request below all points
specified and returns the value at the highest point for a request
above all points specified. On is the default.
int = obj.GetClamping ()
- When zero range clamping is Off, GetValue() returns 0.0 when a
value is requested outside of the points specified.
When zero range clamping is On, GetValue() returns the value at
the value at the lowest point for a request below all points
specified and returns the value at the highest point for a request
above all points specified. On is the default.
obj.ClampingOn ()
- When zero range clamping is Off, GetValue() returns 0.0 when a
value is requested outside of the points specified.
When zero range clamping is On, GetValue() returns the value at
the value at the lowest point for a request below all points
specified and returns the value at the highest point for a request
above all points specified. On is the default.
obj.ClampingOff ()
- When zero range clamping is Off, GetValue() returns 0.0 when a
value is requested outside of the points specified.
When zero range clamping is On, GetValue() returns the value at
the value at the lowest point for a request below all points
specified and returns the value at the highest point for a request
above all points specified. On is the default.
string = obj.GetType ()
- Return the type of function:
Function Types:
0 : Constant (No change in slope between end points)
1 : NonDecreasing (Always increasing or zero slope)
2 : NonIncreasing (Always decreasing or zero slope)
3 : Varied (Contains both decreasing and increasing slopes)
double = obj.GetFirstNonZeroValue ()
- Returns the first point location which precedes a non-zero segment of the
function. Note that the value at this point may be zero.
obj.Initialize ()
- Clears out the current function. A newly created vtkPiecewiseFunction
is alreay initialized, so there is no need to call this method which
in turn simply calls RemoveAllPoints()
obj.SetAllowDuplicateScalars (int )
- Toggle whether to allow duplicate scalar values in the piecewise
function (off by default).
int = obj.GetAllowDuplicateScalars ()
- Toggle whether to allow duplicate scalar values in the piecewise
function (off by default).
obj.AllowDuplicateScalarsOn ()
- Toggle whether to allow duplicate scalar values in the piecewise
function (off by default).
obj.AllowDuplicateScalarsOff ()
- Toggle whether to allow duplicate scalar values in the piecewise
function (off by default).