mapteksdk.data.coordinate_systems module

Support for coordinate systems.

By default, points and other primitives are defined in an arbitrary space with no correlation to the real world. A coordinate system provides a mapping of the coordinates to locations in the real world.

exception LocalTransformNotSupportedError

Bases: Exception

Geographic projections do not support local transforms. This error is raised when a user attempts to define a local transform for such a coordinate system.

args

with_traceback()

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

class CoordinateSystem(crs, local_transform=None)

Bases: object

A PROJ coordinate system (see https://proj.org) with an optional additional local transformation.

A local transformation can be used when the standard map project is not convenient. For example a local origin, an X direction aligned to the strike of a pit and a scaling factor to counter the UTM distortion away from the central meridian would create a coordinate system that is more convenient to use and represents distances more accurately.

Parameters

• crs (pyproj.CRS or string) – Coordinate reference system of the coordinate system. This can be a pyproj.CRS object or a “Well Known Text” (wkt) string.

• local_transform (LocalTransform) – The local transform of the coordinate system. The default is no local transform.

Raises

• pyproj.exceptions.CRSError – If crs cannot be parsed as a wkt string.

• LocalTransformNotSupportedError – If the CRS is a geographic projection and local transform was specified.

Warning

Vulcan GeologyCore 2021 and PointStudio 2021/2021.1 use PROJ version 6.3.1 which roughly matches up with the version of PROJ used by pyproj versions 2.5.0 and 2.6.0. mapteksdk will work with newer versions of pyproj, however if the installed version of pyproj uses a newer version of PROJ than the connected application then pyproj may be able to represent coordinate systems which the application cannot understand.

property crs

The base coordinate system of the object. This is an object of type pyproj.CRS.

When set, this can be a pyproj.CRS class or a string in wkt format.

Raises

• TypeError – If set to a value which is not a pyproj.CRS.

• pyproj.exceptions.CRSError – If set to a string which cannot be converted to a CRS.

property local_transform

The local transform applied to the coordinate system to provide a more convenient coordinate system.

Raises

• TypeError – If set to a value which is not a LocalTransform.

• LocalTransformNotSupportedError – If set when CRS is a geographic projection.

class LocalTransform(local_transform=None, *, horizontal_origin=None, horizontal_scale_factor=nan, horizontal_rotation=nan, horizontal_shift=None, vertical_shift=nan, vertical_origin=None, vertical_slope=None)

Bases: object

Class representing a local transform that can be applied on top of a coordinate system to provide a more useful and accurate coordinate system for a particular application.

Parameters

• local_transform – The local transform represented as eleven floats. See notes for details on the meaning of each float. If this is specified, all other parameters are ignored. Generally users of the SDK will use the other arguments in preference to this one.

• horizontal_origin (numpy.ndarray) – Numpy array of shape (2,) representing the horizontal origin. Default is [nan, nan].

• horizontal_scale_factor (float) – Float representing the horizontal scale factor. Default is nan.

• horizontal_rotation (float) – Float represtenting the horizontal rotation. Default is nan.

• horizontal_shift (numpy.ndarray) – Numpy array of shape (2,) representing the horizontal shift. Default is [nan, nan]

• vertical_shift (float) – Float representing the vertical shift. Default is nan.

• vertical_origin (numpy.ndarray) – Numpy array of shape (2,) representing the vertical origin. Default is [nan, nan]

• vertical_slope (numpy.ndarray) – Numpy array of shape (2,) representing the vertical slope. Default is [nan, nan]

Raises

• ValueError – If the numpy arrays shape is not (11,).

• TypeError – If any of the local transform parameters are an incorrect type.

Notes

This local transform object can be represented as a numpy array of eleven floats. These floats have the following meaning:

0. Horizontal origin X

1. Horizontal origin Y

2. Horizontal scale factor

3. Horizontal rotation

4. Horizontal shift X

5. Horizontal shift Y

6. Vertical shift

7. Vertical origin X

8. Vertical origin Y

9. Vertical slope X

10. Vertical slope Y

property horizontal_origin

The origin in the pre-calibrated coordinate system about which the coordinates are scaled and rotated.

This is a numpy array of shape (2,) in the form [X, Y] (or [Northing, Easting])

Raises

• ValueError – If the value cannot be converted to an ndarray with shape (2,).

• TypeError – If set to a value which cannot be converted to a floating point number.

property horizontal_scale_factor

The scale factor of the points about the horizontal origin.

Raises

• ValueError – If set to a value which cannot be converted to a float.

• ValueError – If set to a non-nan value when the horizontal origin has not been set.

property horizontal_rotation

The clockwise horizontal rotation applied to the coordinates about the horizontal origin. The value is in radians.

Raises

• ValueError – If set to a value which cannot be converted to a float.

• ValueError – If set to a non-nan value when the horizontal origin has not been set.

property horizontal_shift

The translation applied to the coordinates relative to the horizontal origin.

Raises

• ValueError – If the value cannot be converted to an ndarray with shape (2,).

• TypeError – If set to a value which cannot be converted to a floating point number.

property vertical_shift

The translation of the coordinates in the z direction. A positive value shifts upwards.

Raises

ValueError – If set to a value which cannot be converted to a float.

property vertical_origin

The origin of the plane used for a position dependent vertical shift. vertical_slope defines the slope of this plane. The point is defined in the post horizontal calibration system.

Raises

• ValueError – If the value cannot be converted to an ndarray with shape (2,).

• TypeError – If set to a value which cannot be converted to a floating point number.

property vertical_slope

The slope of the plane in parts per million in the form [East, North]. The origin or the plane is defined by vertical_origin. Each value can be considered the height change in mm over a horizontal distance of 1km in the specified direction.

Raises

• ValueError – If the value cannot be converted to an ndarray with shape (2,).

• TypeError – If set to a value which cannot be converted to a floating point number.

to_numpy()

Converts the local transform to a numpy array of shape (11,). See notes on the class for an explanation of each element.