Class: QgsMeshDataBlock

A block of integers/doubles from a mesh dataset.

QgsMeshDataBlock can be used to retrieve:

  • active flags (e.g. face’s active integer flag)

  • scalars (e.g. scalar dataset double values)

  • vectors (e.g. vector dataset doubles x,y values)

Data are implicitly shared, so the class can be quickly copied std.numeric_limits<double>.quiet_NaN() represents NODATA value

Data can be accessed all at once with values() (faster) or value by value (slower) with active() or value()

Added in version 3.6.

class qgis.core.QgsMeshDataBlock[source]

Bases: object

__init__()

Constructs an invalid block

__init__(type: QgsMeshDataBlock.DataType, count: int)

Constructs a new block

Parameters:
__init__(a0: QgsMeshDataBlock)
Parameters:

a0 (QgsMeshDataBlock)

ActiveFlagInteger = 0
class DataType

Bases: int

ScalarDouble = 1
Vector2DDouble = 2
active(self, index: int) → bool[source]

Returns a value for active flag by the index For scalar and vector 2d the behavior is undefined

active(self) -> List[int] Returns active flag array

Even for active flag valid dataset, the returned array could be empty. This means that the data provider/dataset does not support active flag capability, so all faces are active by default.

For scalar and vector 2d the behavior is undefined

Added in version 3.12.

Parameters:

index (int)

Return type:

bool

count(self) → int[source]

Number of items stored in the block

Return type:

int

isValid(self) → bool[source]

Whether the block is valid

Return type:

bool

setActive(self, vals: Iterable[int])[source]

Sets active flag values.

If the data provider/datasets does not have active flag capability (== all values are valid), just set block validity by setValid( True )

Parameters:

vals (Iterable[int]) – value vector with size count()

For scalar and vector 2d the behavior is undefined

Added in version 3.12.

setValid(self, valid: bool)[source]

Sets block validity

Parameters:

valid (bool)

setValues(self, vals: Iterable[float])[source]

Sets values

For scalar datasets, it must have size count() For vector datasets, it must have size 2 * count() For active flag the behavior is undefined

Added in version 3.12.

Parameters:

vals (Iterable[float])

type(self) → QgsMeshDataBlock.DataType[source]

Type of data stored in the block

Return type:

QgsMeshDataBlock.DataType

value(self, index: int) → QgsMeshDatasetValue[source]

Returns a value represented by the index For active flag the behavior is undefined

Parameters:

index (int)

Return type:

QgsMeshDatasetValue

values(self) → List[float]

Returns buffer to the array with values For vector it is pairs (x1, y1, x2, y2, … )

Added in version 3.12.

Return type:

List[float]