DataArray

Source (.js)Source (.d.ts)

Introduction

vtkDataArray is an abstract superclass for data array objects containing numeric data.

Methods

allocate

Resize the array to the requested number of extra tuples (added to the current number of tuples) and preserve data. model.size WILL NOT be modified. This is useful before multiple calls to insertNextTuple() or insertNextTuples().

Argument	Type	Required	Description
extraNumTuples	Number	Yes	Number of tuples to allocate memory wise.

computeRange

Compute range of a given array. The array could be composed of tuples and individual component range could be computed as well as magnitude.

const array = [x0, y0, z0, x1, y1, z1, ..., xn, yn, zn];
const { min: yMin, max: yMax } = computeRange(array, 1, 3);
const { min: minMagnitude, max: maxMagnitude } = computeRange(array, -1, 3);

Argument	Type	Required	Description
values	Array[Number]	Yes	Array to go through to extract the range from
component	Number	No	(default: 0) indice to use inside tuple size
numberOfComponents	Number	No	(default: 1) size of the tuple

dataChange

Call this method when the underlying data has changed This method calls modified() For example, when you need to modify chunks of the array, it is faster to get the underlying array with getData(), modify it, and then call dataChange().

deepCopy

Deep copy of another vtkDataArray into this one.

Argument	Type	Required	Description
other	vtkDataArray	Yes

extend

Method use to decorate a given object (publicAPI+model) with vtkDataArray characteristics.

Argument	Type	Required	Description
publicAPI		Yes	object on which methods will be bounds (public)
model		Yes	object on which data structure will be bounds (protected)
initialValues	object	No	(default: {}) Must pass a number > 0 for size except if empty: true is also passed or a non-empty typed array for values.

fastComputeRange

Compute range of a given array, it only supports 1D arrays.

Argument	Type	Required	Description
values	Array[Number]	Yes	Array to go through to extract the range from
offset	Number	Yes	offset index to select the desired component in the tuple
numberOfComponents	Number	Yes	size of tuple in a multi-channel array

findTuple

Convenient method to search the index of the first matching tuple in the array. This is a naïve search, consider using a "locator" instead.

Argument	Type	Required	Description
tupleToSearch	Array<Number> or TypedArray	Yes
precision	Number	Yes	(1e-6 by default)

Returns

Type	Description
Number	the index of the tuple if found, -1 otherwise.

getComponent

Get the component for a given tupleIdx.

Argument	Type	Required	Description
tupleIdx	Number	Yes
componentIndex	Number	No	(default: 0)

getData

getDataType

Return the name of a typed array

const isFloat32 = ('Float32Array' === getDataType(array));
const clone = new macro.TYPED_ARRAYS[getDataType(array)](array.length);

Argument	Type	Required	Description
typedArray		Yes	to extract its type from

getDataType

Get the data type of this array as a string.

Returns

Type	Description
String

getElementComponentSize

Get the size, in bytes, of the lowest-level element of an array.

getMaxNorm

Return the max norm of a given vtkDataArray

Argument	Type	Required	Description
dataArray		Yes	to process

getName

Get the name of the array.

Returns

Type	Description
String

getNumberOfComponents

Get the dimension (n) of the components.

Returns

Type	Description
Number

getNumberOfTuples

Get the actual number of complete tuples (a component group) in the array.

Returns

Type	Description
Number

getNumberOfValues

Get the actual number of values in the array, which is equal to getNumberOfTuples() * getNumberOfComponents().

Returns

Type	Description
Number

getRange

Get the range of the given component.

Argument	Type	Required	Description
componentIndex	Number	Yes	(default: -1)

getRanges

Returns an array of the ranges for each component of the DataArray. Defaults to computing all the ranges if they aren't already computed.

If the number of components is greater than 1, the last element in the ranges array is the min,max magnitude of the dataset. This is the same as calling getRange(-1).

Passing getRanges(false) will return a clone of the ranges that have already been computed. This is useful when you want to avoid recomputing the ranges, which can be expensive.

Argument	Type	Required	Description
computeRanges	boolean	No	(default: true)

Returns

Type	Description
Array[vtkRange]

getState

Get the state of this array.

Pass { preserveTypedArrays: true } to keep TypedArray values without converting and copying to a plain Array.

Returns

Type	Description
object

getTuple

Get the tuple at the given index.

For performance reasons, it is advised to pass a 'tupleToFill': const x = [];for (int i = 0; i < N; ++i) { dataArray.getTuple(idx, x); ...instead of:for (int i = 0; i < N; ++i) { const x = dataArray.getTuple(idx);...

Argument	Type	Required	Description
idx	Number	Yes
tupleToFill	Array[Number] or TypedArray	No	(default [])

Returns

Type	Description
Array[Number] or TypedArray

getTupleLocation

Argument	Type	Required	Description
idx	Number	No	(default: 1)

Returns

Type	Description
Number

getTuples

Get the tuples between fromId (inclusive) and toId (exclusive).

If fromId or toId is negative, it refers to a tuple index from the end of the underlying typedArray. If the range between fromId and toId is invalid, getTuples returns null.

NOTE: Any changes to the returned TypedArray will result in changes to this DataArray's underlying TypedArray.

Argument	Type	Required	Description
fromId	Number	No	(default: 0)
toId	Number	No	(default: publicAPI.getNumberOfTuples())

Returns

Type	Description
Nullable<TypedArray>

getValue

Get the value at a flat array index.

Argument	Type	Required	Description
valueIdx	Number	Yes

initialize

Reset this array. NOTE: This won't touch the actual memory of the underlying typedArray.

insertNextTuple

Insert the given tuple at the next available slot and return the index of the insertion. NOTE: May resize the data values array. "Safe" version of setTuple.

Argument	Type	Required	Description
tuple	Array<Number> or TypedArray	Yes

Returns

Type	Description
Number	Index of the inserted tuple.

insertNextTuples

Convenience function to insert an array of tuples with insertNextTuple. NOTE: tuples.length must be a multiple of getNumberOfComponents.

Argument	Type	Required	Description
tuples	Array<Number> or TypedArray	Yes

Returns

Type	Description
	The index of the last inserted tuple

insertTuple

Insert the given tuple at the given index. NOTE: May resize the data values array. "Safe" version of setTuple.

A typical usage is when vtkDataArray is initialized with initialValues = { size: 0, values: new Uint8Array(1000) }, where an empty but pre-allocated array with 1'000 components is created. The component values can then be inserted with insertTuple() or insertNextTuple() without requiring new memory allocation until the size of 1'000 is exceeded (e.g. after inserting the 250th 4-component tuple).

insertTuple increases the number of tuples (getNumberOfTuples()).

Argument	Type	Required	Description
idx	Number	Yes
tuple	Array<Number> or TypedArray	Yes

Returns

Type	Description
Number	Index of the inserted tuple

insertTuples

Insert tuples starting at the given idx.

Argument	Type	Required	Description
idx	Number	Yes
tuples	Array<Number> or TypedArray	Yes	Flat array of tuples to insert

Returns

Type	Description
	The index of the last inserted tuple

interpolateTuple

Interpolate between the tuples retrieved from source1 and source2 with the resp. indices and set the resulting tuple to the idx of this DataArray.

Argument	Type	Required	Description
idx,	NonNegativeInteger	Yes
source1,	vtkDataArray	Yes
source1Idx,	NonNegativeInteger	Yes
source2,	vtkDataArray	Yes
source2Idx,	NonNegativeInteger	Yes
t	Float	Yes

newClone

Return a clone of this array.

Returns

Type	Description
vtkDataArray

newInstance

Method use to create a new instance of vtkDataArray

If the provided values is a plain Array and dataType is not explicitly provided, then the vtkDataArray data type will be a Float32Array.

Argument	Type	Required	Description
initialValues	object	No	for pre-setting some of its content

resize

Resize the array to the requested number of tuples and preserve data. Increasing the array size may allocate extra memory beyond what was requested. Decreasing the array size will trim memory to the requested size. model.size WILL be modified according ot the new size. If requestedNumTuples > getNumberOfTuples(), it creates a new typed array and copies the old values to the new array. If requestedNumTuples < getNumberOfTuples(), the typed array is untouched, only model.size is modified.

Argument	Type	Required	Description
requestedNumTuples	Number	Yes	Final expected number of tuples; must be >= 0

Returns

Type	Description
Boolean	True if a resize occurred. False if the size is unchanged or requestedNumTuples is invalid.

setComponent

Set the component value for a given tupleIdx and componentIndex.

Argument	Type	Required	Description
tupleIdx	Number	Yes
componentIndex	Number	Yes
value	Number	Yes

setData

Set the data of this array. Optionally pass ´numberOfComponents´ to overwrite this dataArray's numberOfComponents. If this dataArray's numberOfComponents doesn't divide the given array's length, this dataArray's numberOfComponents is set to 1.

Argument	Type	Required	Description
typedArray	TypedArray	Yes	The typed array value.
numberOfComponents	Number	No

setName

Set the name of this array.

Argument	Type	Required	Description
name	String	Yes

Returns

Type	Description
Boolean

setNumberOfComponents

Set the dimension (n) of the components.

Argument	Type	Required	Description
numberOfComponents	Number	Yes

setRange

Argument	Type	Required	Description
rangeValue	vtkRange	Yes
componentIndex	Number	Yes

setTuple

Set the given tuple at the given index.

Argument	Type	Required	Description
idx	Number	Yes
tuple	Array<Number> or TypedArray	Yes

Returns

Type	Description
	Whether any value changed.

setTuples

Set the given tuples starting at the given index.

Argument	Type	Required	Description
idx	Number	Yes
tuples	Array<Number> or TypedArray	Yes

Returns

Type	Description
	Whether any value changed.

setValue

Set the value at a flat array index.

Argument	Type	Required	Description
valueIdx	Number	Yes
value	Number	Yes