28.2.7. Vector geoprocessing
28.2.7.1. Buffer vectors
Create buffers around the features of a vector layer.
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input layer |
|
[vector: any] |
The input vector layer |
Geometry column name |
|
[string] Default: ‘geometry’ |
The name of the input layer geometry column to use |
Buffer distance |
|
[number] Default: 10.0 |
Minimum: 0.0 |
Dissolve by attribute Optional |
|
[tablefield: any] Default: None |
Field to use for dissolving |
Dissolve results |
|
[boolean] Default: False |
|
Produce one feature for each geometry in any kind of geometry collection in the source file |
|
[boolean] Default: False |
|
Buffer |
|
[vector: polygon] Default: |
Specify the output buffer layer. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Additional creation options Optional |
|
[string] Default: ‘’ (no additional options) |
Additional GDAL creation options. |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Buffer |
|
[vector: polygon] |
The output buffer layer |
Python code
Algorithm ID: gdal:buffervectors
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.
28.2.7.2. Clip vector by extent
Clips any OGR-supported vector file to a given extent.
This algorithm is derived from the GDAL ogr2ogr utility.
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input layer |
|
[vector: any] |
The input vector layer |
Clip extent |
|
[extent] |
Defines the bounding box that should be used for the output vector file. It has to be defined in target CRS coordinates. Available methods are:
|
Clipped (extent) |
|
[same as input] Default: |
Specify the output (clipped) layer. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Additional creation options Optional |
|
[string] Default: ‘’ (no additional options) |
Additional GDAL creation options. |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Clipped (extent) |
|
[same as input] |
The output (clipped) layer. The default format is “ESRI Shapefile”. |
Python code
Algorithm ID: gdal:clipvectorbyextent
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.
28.2.7.3. Clip vector by mask layer
Clips any OGR-supported vector layer by a mask polygon layer.
This algorithm is derived from the GDAL ogr2ogr utility.
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input layer |
|
[vector: any] |
The input vector layer |
Mask layer |
|
[vector: polygon] |
Layer to be used as clipping extent for the input vector layer. |
Clipped (mask) |
|
[same as input] Default: |
The output (masked) layer. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Additional creation options Optional |
|
[string] Default: ‘’ (no additional options) |
Additional GDAL creation options. |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Clipped (mask) |
|
[same as input] |
The output (masked) layer. The default format is “ESRI Shapefile”. |
Python code
Algorithm ID: gdal:clipvectorbypolygon
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.
28.2.7.4. Dissolve
Dissolve (combine) geometries that have the same value for a given attribute / field. The output geometries are multipart.
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input layer |
|
[vector: any] |
The input layer to dissolve |
Dissolve field Optional |
|
[tablefield: any] |
The field of the input layer to use for dissolving |
Geometry column name |
|
[string] Default: ‘geometry’ |
The name of the input layer geometry column to use for dissolving. |
Dissolved |
|
[same as input] Default: |
Specify the output layer. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Produce one feature for each geometry in any kind of geometry collection in the source file |
|
[boolean] Default: False |
Produce one feature for each geometry in any kind of geometry collection in the source file |
Keep input attributes |
|
[boolean] Default: False |
Keep all attributes from the input layer |
Count dissolved features |
|
[boolean] Default: False |
Count the dissolved features and include it in the output layer. |
Compute area and perimeter of dissolved features |
|
[boolean] Default: False |
|
Compute min/max/sum/mean for attribute |
|
[boolean] Default: False |
Calculate statistics (min, max, sum and mean) for the numeric attribute specified and include them in the output layer |
Numeric attribute to calculate statistics on Optional |
|
[tablefield: numeric] |
The numeric attribute to calculate statistics on |
Additional creation options Optional |
|
[string] Default: ‘’ (no additional options) |
Additional GDAL creation options. |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Dissolved |
|
[same as input] |
|
Python code
Algorithm ID: gdal:dissolve
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.
28.2.7.5. Offset curve
Offsets lines by a specified distance. Positive distances will offset lines to the left, and negative distances will offset them to the right.
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input layer |
|
[vector: line] |
The input line layer |
Geometry column name |
|
[string] Default: ‘geometry’ |
The name of the input layer geometry column to use |
Offset distance (left-sided: positive, right-sided: negative) |
|
[number] Default: 10.0 |
|
Offset curve |
|
[vector: line] Default: |
Specify the output line layer. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Additional creation options Optional |
|
[string] Default: ‘’ (no additional options) |
Additional GDAL creation options. |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Offset curve |
|
[vector: line] |
The output offset curve layer |
Python code
Algorithm ID: gdal:offsetcurve
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.
28.2.7.6. One side buffer
Creates a buffer on one side (right or left) of the lines in a line vector layer.
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input layer |
|
[vector: line] |
The input line layer |
Geometry column name |
|
[string] Default: ‘geometry’ |
The name of the input layer geometry column to use |
Buffer distance |
|
[number] Default: 10.0 |
|
Buffer side |
|
[enumeration] Default: 0 |
One of:
|
Dissolve by attribute Optional |
|
[tablefield: any] Default: None |
Field to use for dissolving |
Dissolve all results |
|
[boolean] Default: False |
|
Produce one feature for each geometry in any kind of geometry collection in the source file |
|
[boolean] Default: False |
|
One-sided buffer |
|
[vector: polygon] Default: |
Specify the output buffer layer. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Additional creation options Optional |
|
[string] Default: ‘’ (no additional options) |
Additional GDAL creation options. |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
One-sided buffer |
|
[vector: polygon] |
The output buffer layer |
Python code
Algorithm ID: gdal:onesidebuffer
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.
28.2.7.7. Points along lines
Generates a point on each line of a line vector layer at a distance from start. The distance is provided as a fraction of the line length.
Parameters
Basic parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Input layer |
|
[vector: line] |
The input line layer |
Geometry column name |
|
[string] Default: ‘geometry’ |
The name of the input layer geometry column to use |
Distance from line start represented as a fraction of line length |
|
[number] Default: 0.5 (middle of the line) |
|
Points along lines |
|
[vector: point] Default: |
Specify the output point layer. One of:
|
Advanced parameters
Label |
Name |
Type |
Description |
---|---|---|---|
Additional creation options Optional |
|
[string] Default: ‘’ (no additional options) |
Additional GDAL creation options. |
Outputs
Label |
Name |
Type |
Description |
---|---|---|---|
Points along line |
|
[vector: point] |
The output point layer |
Python code
Algorithm ID: gdal:pointsalonglines
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.