mapteksdk.data.base module

The base classes of all objects in a Project.

The basic unit of data in a Project is an object. All objects in a Project are subclasses of DataObject and thus can access the properties and functions defined by DataObject.

Objects which are intended to be visualised, such as Surface, Polyline or Polygon, inherit from the Topology class.

Objects which are not intended to be visualised on their own, such as colour maps and rasters, inherit directly from the DataObject class.

For objects which contain other objects, see mapteksdk.data.containers.

exception AlreadyClosedError

Bases: RuntimeError

Error raised when the user attempts to close a closed object.

args

with_traceback(): Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

class Extent(minimum, maximum)

Bases: object

A multidimensional, axially-aligned “intervals” or “extents”.

This extent is bound to a volume in 3D space.

minimum

Point representing minimum values in the form [x, y, z].

Type: tuple

maximum

Point representing maximum values in the form [x, y, z].

Type: tuple

property centre

Returns the center of the extent.

Returns: Point representing the center of the extent.
Return type: point

property length

The length is the maximum of the X, Y or Z dimension.

Returns: Maximum width of the extent.
Return type: float

as_numpy()

Returns the extent as a numpy array.

Returns: The extent representing as a numpy array.
Return type: np.array

class DataObject(object_id, lock_type)

Bases: object

The basic unit of data in a Project.

Each object can be referenced (opened/loaded) from its ID, see ObjectID, Project.read() and Project.edit().

property id

Object ID that uniquely references this object in the project.

Returns: The unique id of this object.
Return type: ObjectID

property lock_type

Indicates whether operating in read-only or read-write mode.

Returns: The type of lock.
Return type: LockType

close()

Closes the object. This should be called as soon as you are finished working with an object. To avoid needing to remember to call this function, open the object using a with block and project.read(), project.new() or project.edit(). Those functions automatically call this function at the end of the with block.

A closed object cannot be used for further reading or writing. The ID of a closed object may be queried and this can then be used to re-open the object.

Raises: AlreadyClosedError – If the object has already been closed.

property created_date

The date and time (in UTC) of when this object was created.

Returns: The date and time the object was created. 0:0:0 1/1/1970 if the operation failed.
Return type: datetime.datetime

property modified_date

The date and time (in UTC) of when this object was last modified.

Returns: The date and time this object was last modified. 0:0:0 1/1/1970 if the operation failed.
Return type: datetime.datetime

set_attribute(name, dtype, data)

Sets the value for the object attribute with the specified name. This will overwrite any existing attribute with the specified name.

Parameters

name (str) – The name of the object attribute for which the value should be set.
dtype (type) – The type of data to assign to the attribute. This should be a type from the ctypes module or datetime.datetime or datetime.date. Passing bool is equivalent to passing ctypes.c_bool. Passing str is equivalent to passing ctypes.c_char_p. Passing int is equivalent to passing ctypes.c_int16. Passing float is equivalent to passing ctypes.c_double.
data (any) – The value to assign to object attribute name. For dtype = datetime.datetime this can either be a datetime object or timestamp which will be passed directly to datetime.utcfromtimestamp(). For dtype = datetime.date this can either be a date object or a tuple of the form: (year, month, day).

Raises

ValueError – If dtype is an unsupported type.
TypeError – If value is an inappropriate type for object attribute name.
RuntimeError – If a different error occurs.

Warning

Object attributes are saved separately from the object itself - any changes made by this function (assuming it does not raise an error) will be saved even if save() is not called (for example, due to an error being raised by another function).

Examples

Create an object attribute on an object at “target” and then read its value.

>>> import ctypes
>>> from mapteksdk.project import Project
>>> project = Project()
>>> with project.edit("target") as edit_object:
...     edit_object.set_attribute("count", ctypes.c_int16, 0)
... with project.read("target") as read_object:
...     print(read_object.get_attribute("count"))
0

attribute_names()

Returns a list containing the names of all object-level attributes. Use this to iterate over the object attributes.

Returns: List containing the attribute names.
Return type: list

Examples

Iterate over all object attributes of the object stared at “target” and print their values.

>>> from mapteksdk.project import Project
>>> project = Project()
>>> with project.read("target") as read_object:
...     for name in read_object.attribute_names():
...         print(name, ":", read_object.get_attribute(name))

get_attribute(name)

Returns the value for the attribute with the specified name.

Parameters: name (str) – The name of the object attribute to get the value for.
Returns: The value of the object attribute name. For dtype = datetime.datetime this is an integer representing the number of milliseconds since 1st Jan 1970. For dtype = datetime.date this is a tuple of the form: (year, month, day).
Return type: any
Raises: KeyError – If there is no object attribute called name.

Warning

In the future this function may be changed to return datetime.datetime and datetime.date objects instead of the current representation for object attributes of type datetime.datetime or datetime.date.

get_attribute_type(name)

Returns the type of the attribute with the specified name.

Parameters: name (str) – Name of the attribute whose type should be returned.
Returns: The type of the object attribute name.
Return type: type
Raises: KeyError – If there is no object attribute called name.

delete_all_attributes()

Delete all object attributes attached to an object.

This only deletes object attributes and has no effect on PrimitiveAttributes.

Raises: RuntimeError – If all attributes cannot be deleted.

delete_attribute(attribute)

Deletes a single object-level attribute.

Deleting a non-existent object attribute will not raise an error.

Parameters: attribute (str) – Name of attribute to delete.
Returns: True if the object attribute existed and was deleted; False if the object attribute did not exist.
Return type: bool
Raises: RuntimeError – If the attribute cannot be deleted.

class Topology(object_id, lock_type)

Bases: mapteksdk.data.base.DataObject

Base class for “geometric objects” in a Project.

This object is best thought of as the union of the following:

An arrangement of topological “primitives” including their location in space (known as their geometry).

The connectivity relationships between them (known as their topology).

The properties applied to them.

A given geometric object may contain any number of any of the six basic primitives: points, edges, facets (triangles), tetras (4 sided polyhedra), cells (quadrilaterals) and blocks (cubes or rectangular boxes). However, derived classes typically enforce constraints on the type and number of each primitive allowed in objects of their type. For example an edge chain will have points and edges but not facets.

close(): Closes the object and saves the changes to the Project, preventing any further changes.

classmethod static_type()

Return the type of a topology as stored in a Project.

This can be used for determining if the type of an object is topology.

save()

Save the changes made to the object.

Generally a user does not need to call this function because it is called automatically at the end of a with block using Project.new() or Project.edit().

property extent: The axes aligned bounding extent of the object.

get_colour_map()

Return the ID of the colour map object currently associated with this object.

Returns: The ID of the colour map object or null object ID if there is no colour map.
Return type: ObjectID

property rasters

A dictionary of raster indices and Object IDs of the raster images currently associated with this object.

The keys are the raster ids and the values are the Object IDs of the associated rasters. Note that all raster ids are integers however they may not be consecutive - for example, an object may have raster ids 0, 1, 5 and 200.

Notes

Rasters with higher indices appear on top of rasters with lower indices. The maximum possible raster id is 255.

Removing a raster from this dictionary will not remove the raster association from the object. Use dissociate_raster to do this.

Examples

Iterate over all rasters on an object and invert the colours. Note that this will fail if there is no object at the path “target” and it will do nothing if no rasters are associated with the target.

>>> from mapteksdk.project import Project
>>> project = Project()
>>> with project.read("target") as read_object:
...     for raster in read_object.rasters.values():
...         with project.edit(raster) as edit_raster:
...             edit_raster.pixels[:, :3] = 255 - edit_raster.pixels[:, :3]

property coordinate_system

The coordinate system the points of this object are in.

Warning

Setting this property does not change the points. This is only a label stating the coordinate system the points are in.

Notes

If the object has no coordinate system, this will be None.

Changes are done directly in the project and will not be undone if an error occurs.

Examples

Creating an edge network and setting the coordinate system to be WGS84. Note that setting the coordinate system does not change the points. It is only stating which coordinate system the points are in.

>>> from pyproj import CRS
>>> from mapteksdk.project import Project
>>> from mapteksdk.data import Polygon
>>> project = Project()
>>> with project.new("cad/rectangle", Polygon) as new_edges:
...     # Coordinates are in the form [longitude, latitude]
...     new_edges.points = [[112, 9], [112, 44], [154, 44], [154, 9]]
...     new_edges.coordinate_system = CRS.from_epsg(4326)

Often a standard map projection is not convenient or accurate for a given application. In such cases a local transform can be provided to allow coordinates to be specified in a more convenient system. The below example defines a local transform where the origin is translated 1.2 degrees north and 2.1 degree east, points are scaled to be twice as far from the horizontal origin and the coordinates are rotated 45 degrees clockwise about the horizontal_origin. Note that the points of the polygon are specified in the coordinate system after the local transform has been applied.

>>> import math
>>> from pyproj import CRS
>>> from mapteksdk.project import Project
>>> from mapteksdk.data import Polygon, CoordinateSystem, LocalTransform
>>> project = Project()
>>> transform = LocalTransform(
...     horizontal_origin = [1.2, 2.1],
...     horizontal_scale_factor = 2,
...     horizontal_rotation = math.pi / 4)
>>> system = CoordinateSystem(CRS.from_epsg(20249), transform)
>>> with project.new("cad/rectangle_transform", Polygon) as new_edges:
...     new_edges.points = [[112, 9], [112, 44], [154, 44], [154, 9]]
...     new_edges.coordinate_system = system

See also

mapteksdk.data.coordinate_systems.CoordinateSystem: Allows for a coordinate system to be defined with an optional local transform.

dissociate_raster(raster)

Removes the raster from the object.

This is done directly on the Project and will not be undone if an error occurs.

Parameters: raster (ObjectID or Raster) – The raster to dissociate.
Returns: True if the raster was successfully dissociated from the object, False if the raster was not associated with the object.
Return type: bool
Raises: TypeError – If raster is not a Raster.

Notes

This only removes the association between the Raster and the object, it does not clear the registration information from the Raster.

Examples

Dissociate the first raster found on a picked object.

>>> from mapteksdk.project import Project
>>> from mapteksdk import operations
>>> project = Project()
>>> oid = operations.object_pick(
...     support_label="Pick an object to remove a raster from.")
... with project.edit(oid) as data_object:
...     report = f"There were no raster to remove from {oid.path}"
...     for index in data_object.rasters:
...         data_object.dissociate_raster(data_object.rasters[index])
...         report = f"Removed raster {index} from {oid.path}"
...         break
... # Now that the raster is dissociated and the object is closed,
... # the raster can be associated with a different object.
... operations.write_report("Remove Raster", report)

attribute_names()

Returns a list containing the names of all object-level attributes. Use this to iterate over the object attributes.

Returns: List containing the attribute names.
Return type: list

Examples

Iterate over all object attributes of the object stared at “target” and print their values.

>>> from mapteksdk.project import Project
>>> project = Project()
>>> with project.read("target") as read_object:
...     for name in read_object.attribute_names():
...         print(name, ":", read_object.get_attribute(name))

property created_date

The date and time (in UTC) of when this object was created.

Returns: The date and time the object was created. 0:0:0 1/1/1970 if the operation failed.
Return type: datetime.datetime

delete_all_attributes()

Delete all object attributes attached to an object.

This only deletes object attributes and has no effect on PrimitiveAttributes.

Raises: RuntimeError – If all attributes cannot be deleted.

delete_attribute(attribute)

Deletes a single object-level attribute.

Deleting a non-existent object attribute will not raise an error.

Parameters: attribute (str) – Name of attribute to delete.
Returns: True if the object attribute existed and was deleted; False if the object attribute did not exist.
Return type: bool
Raises: RuntimeError – If the attribute cannot be deleted.

get_attribute(name)

Returns the value for the attribute with the specified name.

Parameters: name (str) – The name of the object attribute to get the value for.
Returns: The value of the object attribute name. For dtype = datetime.datetime this is an integer representing the number of milliseconds since 1st Jan 1970. For dtype = datetime.date this is a tuple of the form: (year, month, day).
Return type: any
Raises: KeyError – If there is no object attribute called name.

Warning

In the future this function may be changed to return datetime.datetime and datetime.date objects instead of the current representation for object attributes of type datetime.datetime or datetime.date.

get_attribute_type(name)

Returns the type of the attribute with the specified name.

Parameters: name (str) – Name of the attribute whose type should be returned.
Returns: The type of the object attribute name.
Return type: type
Raises: KeyError – If there is no object attribute called name.

property id

Object ID that uniquely references this object in the project.

Returns: The unique id of this object.
Return type: ObjectID

property lock_type

Indicates whether operating in read-only or read-write mode.

Returns: The type of lock.
Return type: LockType

property modified_date

The date and time (in UTC) of when this object was last modified.

Returns: The date and time this object was last modified. 0:0:0 1/1/1970 if the operation failed.
Return type: datetime.datetime

set_attribute(name, dtype, data)

Sets the value for the object attribute with the specified name. This will overwrite any existing attribute with the specified name.

Parameters

name (str) – The name of the object attribute for which the value should be set.
dtype (type) – The type of data to assign to the attribute. This should be a type from the ctypes module or datetime.datetime or datetime.date. Passing bool is equivalent to passing ctypes.c_bool. Passing str is equivalent to passing ctypes.c_char_p. Passing int is equivalent to passing ctypes.c_int16. Passing float is equivalent to passing ctypes.c_double.
data (any) – The value to assign to object attribute name. For dtype = datetime.datetime this can either be a datetime object or timestamp which will be passed directly to datetime.utcfromtimestamp(). For dtype = datetime.date this can either be a date object or a tuple of the form: (year, month, day).

Raises

ValueError – If dtype is an unsupported type.
TypeError – If value is an inappropriate type for object attribute name.
RuntimeError – If a different error occurs.

Warning

Object attributes are saved separately from the object itself - any changes made by this function (assuming it does not raise an error) will be saved even if save() is not called (for example, due to an error being raised by another function).

Examples

Create an object attribute on an object at “target” and then read its value.

>>> import ctypes
>>> from mapteksdk.project import Project
>>> project = Project()
>>> with project.edit("target") as edit_object:
...     edit_object.set_attribute("count", ctypes.c_int16, 0)
... with project.read("target") as read_object:
...     print(read_object.get_attribute("count"))
0