Section: Visualization Toolkit Common Classes
vtkAbstractArray is an abstract superclass for data array objects. This class defines an API that all subclasses must support. The data type must be assignable and copy-constructible, but no other assumptions about its type are made. Most of the subclasses of this array deal with numeric data either as scalars or tuples of scalars. A program can use the IsNumeric() method to check whether an instance of vtkAbstractArray contains numbers. It is also possible to test for this by attempting to SafeDownCast an array to an instance of vtkDataArray, although this assumes that all numeric arrays will always be descended from vtkDataArray.
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Every array has a character-string name. The naming of the array occurs automatically when it is instantiated, but you are free to change this name using the SetName() method. (The array name is used for data manipulation.)
To create an instance of class vtkAbstractArray, simply invoke its constructor as follows
obj = vtkAbstractArray
obj
is an instance of the vtkAbstractArray class.
string = obj.GetClassName ()
int = obj.IsA (string name)
vtkAbstractArray = obj.NewInstance ()
vtkAbstractArray = obj.SafeDownCast (vtkObject o)
int = obj.Allocate (vtkIdType sz, vtkIdType ext)
- Allocate memory for this array. Delete old storage only if necessary.
Note that ext is no longer used.
obj.Initialize ()
- Release storage and reset array to initial state.
int = obj.GetDataType ()
- Return the underlying data type. An integer indicating data type is
returned as specified in vtkSetGet.h.
int = obj.GetDataTypeSize ()
- Return the size of the underlying data type. For a bit, 0 is
returned. For string 0 is returned. Arrays with variable length
components return 0.
int = obj.GetElementComponentSize ()
- Return the size, in bytes, of the lowest-level element of an
array. For vtkDataArray and subclasses this is the size of the
data type. For vtkStringArray, this is
sizeof(vtkStdString::value_type), which winds up being
sizeof(char).
obj.SetNumberOfComponents (int )
- Set/Get the dimention (n) of the components. Must be >= 1. Make sure that
this is set before allocation.
int = obj.GetNumberOfComponentsMinValue ()
- Set/Get the dimention (n) of the components. Must be >= 1. Make sure that
this is set before allocation.
int = obj.GetNumberOfComponentsMaxValue ()
- Set/Get the dimention (n) of the components. Must be >= 1. Make sure that
this is set before allocation.
int = obj.GetNumberOfComponents ()
- Set the number of tuples (a component group) in the array. Note that
this may allocate space depending on the number of components.
Also note that if allocation is performed no copy is performed so
existing data will be lost (if data conservation is sought, one may
use the Resize method instead).
obj.SetNumberOfTuples (vtkIdType number)
- Set the number of tuples (a component group) in the array. Note that
this may allocate space depending on the number of components.
Also note that if allocation is performed no copy is performed so
existing data will be lost (if data conservation is sought, one may
use the Resize method instead).
vtkIdType = obj.GetNumberOfTuples ()
- Set the tuple at the ith location using the jth tuple in the source array.
This method assumes that the two arrays have the same type
and structure. Note that range checking and memory allocation is not
performed; use in conjunction with SetNumberOfTuples() to allocate space.
obj.SetTuple (vtkIdType i, vtkIdType j, vtkAbstractArray source)
- Set the tuple at the ith location using the jth tuple in the source array.
This method assumes that the two arrays have the same type
and structure. Note that range checking and memory allocation is not
performed; use in conjunction with SetNumberOfTuples() to allocate space.
obj.InsertTuple (vtkIdType i, vtkIdType j, vtkAbstractArray source)
- Insert the jth tuple in the source array, at ith location in this array.
Note that memory allocation is performed as necessary to hold the data.
vtkIdType = obj.InsertNextTuple (vtkIdType j, vtkAbstractArray source)
- Insert the jth tuple in the source array, at the end in this array.
Note that memory allocation is performed as necessary to hold the data.
Returns the location at which the data was inserted.
obj.GetTuples (vtkIdList ptIds, vtkAbstractArray output)
- Given a list of point ids, return an array of tuples.
You must insure that the output array has been previously
allocated with enough space to hold the data.
obj.GetTuples (vtkIdType p1, vtkIdType p2, vtkAbstractArray output)
- Get the tuples for the range of points ids specified
(i.e., p1->p2 inclusive). You must insure that the output array has
been previously allocated with enough space to hold the data.
obj.DeepCopy (vtkAbstractArray da)
- Deep copy of data. Implementation left to subclasses, which
should support as many type conversions as possible given the
data type.
Subclasses should call vtkAbstractArray::DeepCopy() so that the
information object (if one exists) is copied from \a da.
obj.InterpolateTuple (vtkIdType i, vtkIdList ptIndices, vtkAbstractArray source, double weights)
- Set the ith tuple in this array as the interpolated tuple value,
given the ptIndices in the source array and associated
interpolation weights.
This method assumes that the two arrays are of the same type
and strcuture.
obj.InterpolateTuple (vtkIdType i, vtkIdType id1, vtkAbstractArray source1, vtkIdType id2, vtkAbstractArray source2, double t)
obj.Squeeze ()
- Resize object to just fit data requirement. Reclaims extra memory.
int = obj.Resize (vtkIdType numTuples)
- Resize the array while conserving the data. Returns 1 if
resizing succeeded and 0 otherwise.
obj.Reset ()
- Return the size of the data.
vtkIdType = obj.GetSize ()
- What is the maximum id currently in the array.
vtkIdType = obj.GetMaxId ()
- This method lets the user specify data to be held by the array. The
array argument is a pointer to the data. size is the size of
the array supplied by the user. Set save to 1 to keep the class
from deleting the array when it cleans up or reallocates memory.
The class uses the actual array provided; it does not copy the data
from the supplied array.
long = obj.GetActualMemorySize ()
- Return the memory in kilobytes consumed by this data array. Used to
support streaming and reading/writing data. The value returned is
guaranteed to be greater than or equal to the memory required to
actually represent the data represented by this object. The
information returned is valid only after the pipeline has
been updated.
obj.SetName (string )
- Set/get array's name
string = obj.GetName ()
- Set/get array's name
string = obj.GetDataTypeAsString (void )
- Creates an array for dataType where dataType is one of
VTK_BIT, VTK_CHAR, VTK_UNSIGNED_CHAR, VTK_SHORT,
VTK_UNSIGNED_SHORT, VTK_INT, VTK_UNSIGNED_INT, VTK_LONG,
VTK_UNSIGNED_LONG, VTK_DOUBLE, VTK_DOUBLE, VTK_ID_TYPE,
VTK_STRING.
Note that the data array returned has be deleted by the
user.
int = obj.IsNumeric ()
- This method is here to make backward compatibility easier. It
must return true if and only if an array contains numeric data.
vtkArrayIterator = obj.NewIterator ()
- Subclasses must override this method and provide the right
kind of templated vtkArrayIteratorTemplate.
vtkIdType = obj.GetDataSize ()
- Tell the array explicitly that the data has changed.
This is only necessary to call when you modify the array contents
without using the array's API (i.e. you retrieve a pointer to the
data and modify the array contents). You need to call this so that
the fast lookup will know to rebuild itself. Otherwise, the lookup
functions will give incorrect results.
obj.DataChanged ()
- Tell the array explicitly that the data has changed.
This is only necessary to call when you modify the array contents
without using the array's API (i.e. you retrieve a pointer to the
data and modify the array contents). You need to call this so that
the fast lookup will know to rebuild itself. Otherwise, the lookup
functions will give incorrect results.
obj.ClearLookup ()
- Delete the associated fast lookup data structure on this array,
if it exists. The lookup will be rebuilt on the next call to a lookup
function.
vtkInformation = obj.GetInformation ()
- Get an information object that can be used to annotate the array.
This will always return an instance of vtkInformation, if one is
not currently associated with the array it will be created.
bool = obj.HasInformation ()