24.1.3. Check Geometry

24.1.3.1. Small angles

Compares the angles within line or polygon geometries to a specified threshold, and reports as error any angle below that value.

Fig. 24.2 Reporting errors on a line feature for angles lower than 15°.

See also

Delete small angles

Parameters

Basic parameters

Label	Name	Type	Description
Input layer	INPUT	[vector: line, polygon]	Layer with the geometries to check
Unique feature identifier	UNIQUE_ID	[tablefield: any]	Field storing unique values for feature identification
Minimum angle	MIN_ANGLE	[numeric: double]	Allowed minimum angle between adjacent segments in a feature’s geometry. Any angle below this threshold is reported as error.
Small angle errors	ERRORS	[vector: point] Default: [Create temporary layer]	Specification of the output layer containing the errors location. One of: Create Temporary Layer (TEMPORARY_OUTPUT) Save to File… Save to Geopackage… Save to Database Table… The file encoding can also be changed here.

Advanced parameters

Label	Name	Type	Description
Tolerance	TOLERANCE	[numeric: integer] Default: 8	Numerical precision of geometric operations, given as an integer n, meaning that two vertices less than 10-n apart (in map units) are considered to be merged.

Outputs

Label	Name	Type	Description
Small angle errors	ERRORS	[vector: point]	Output point layer representing the error locations and information (the ID and name of the input layer, the ID, geometry part, ring and vertex index of the erroneous feature, x and y coordinates of the error and the value of the erroneous angle).

Python code

Algorithm ID: native:checkgeometryangle

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Using processing algorithms from the console for details on how to run processing algorithms from the Python console.