27.1.20. Vector selection

27.1.20.1. Extract by attribute 

Creates two vector layers from an input layer: one will contain only matching features while the second will contain all the non-matching features.

The criteria for adding features to the resulting layer is based on the values of an attribute from the input layer.

Lásd még

Select by attribute

Paraméterek

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[vector: any]	Layer to extract features from.
Selection attribute	`FIELD`	[tablefield: any]	Filtering field of the layer
Operator	`OPERATOR`	[felsorolás] Alapértelmezett: 0	Many different operators are available: 0 — = 1 — ≠ 2 — > 3 — >= 4 — < 5 — <= 6 — begins with 7 — contains 8 — is null 9 — is not null 10 — does not contain
Value Optional	`VALUE`	[karakterlánc]	Value to be evaluated
Extracted (attribute)	`OUTPUT`	[same as input] Default: `[Create Temporary Layer]`	Specify the output vector layer for matching features. One of: Create Temporary Layer (`TEMPORARY_OUTPUT`) Mentés fájlba… Save to Geopackage… Save to Database Table… The file encoding can also be changed here.
Extracted (non-matching)	`FAIL_OUTPUT`	[same as input] Default: `[Skip output]`	Specify the output vector layer for non-matching features. One of: Kimenet kihagyása Create Temporary Layer (`TEMPORARY_OUTPUT`) Mentés fájlba… Save to Geopackage… Save to Database Table… The file encoding can also be changed here.

Eredmények

Címke	Név	Típus	Leírás
Extracted (attribute)	`OUTPUT`	[same as input]	Vector layer with matching features from the input layer
Extracted (non-matching)	`FAIL_OUTPUT`	[same as input]	Vector layer with non-matching features from the input layer

Python kód

Algorithm ID: qgis:extractbyattribute

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.

27.1.20.2. Extract by expression 

Creates two vector layers from an input layer: one will contain only matching features while the second will contain all the non-matching features.

The criteria for adding features to the resulting layer is based on a QGIS expression. For more information about expressions see the Kifejezések.

Lásd még

Select by expression

Paraméterek

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[vector: any]	Input vector layer
Expression	`EXPRESSION`	[expression]	Expression to filter the vector layer
Matching features	`OUTPUT`	[same as input] Default: `[Create Temporary Layer]`	Specify the output vector layer for matching features. One of: Create Temporary Layer (`TEMPORARY_OUTPUT`) Mentés fájlba… Save to Geopackage… Save to Database Table… The file encoding can also be changed here.
Non-matching	`FAIL_OUTPUT`	[same as input] Default: `[Skip output]`	Specify the output vector layer for non-matching features. One of: Kimenet kihagyása Create Temporary Layer (`TEMPORARY_OUTPUT`) Mentés fájlba… Save to Geopackage… Save to Database Table… The file encoding can also be changed here.

Eredmények

Címke	Név	Típus	Leírás
Matching features	`OUTPUT`	[same as input]	Vector layer with matching features from the input layer
Non-matching	`FAIL_OUTPUT`	[same as input]	Vector layer with non-matching features from the input layer

Python kód

Algorithm ID: qgis:extractbyexpression

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.

27.1.20.3. Extract by location 

Creates a new vector layer that only contains matching features from an input layer.

The criteria for adding features to the resulting layer is based on the spatial relationship between each feature and the features in an additional layer.

Lásd még

Select by location, Extract within distance

Exploring spatial relations

Geometric predicates are boolean functions used to determine the spatial relation a feature has with another by comparing whether and how their geometries share a portion of space.

../../../../_images/selectbylocation.png — 27.123. ábra Looking for spatial relations between layers

Using the figure above, we are looking for the green circles by spatially comparing them to the orange rectangle feature. Available geometric predicates are:

Intersect: Tests whether a geometry intersects another. Returns 1 (true) if the geometries spatially intersect (share any portion of space - overlap or touch) and 0 if they don’t. In the picture above, this will return circles 1, 2 and 3.
Contain: Returns 1 (true) if and only if no points of b lie in the exterior of a, and at least one point of the interior of b lies in the interior of a. In the picture, no circle is returned, but the rectangle would be if you would look for it the other way around, as it contains circle 1 completely. This is the opposite of are within.
Disjoint: Returns 1 (true) if the geometries do not share any portion of space (no overlap, not touching). Only circle 4 is returned.
Equal: Returns 1 (true) if and only if geometries are exactly the same. No circles will be returned.
Touch: Tests whether a geometry touches another. Returns 1 (true) if the geometries have at least one point in common, but their interiors do not intersect. Only circle 3 is returned.
Overlap: Tests whether a geometry overlaps another. Returns 1 (true) if the geometries share space, are of the same dimension, but are not completely contained by each other. Only circle 2 is returned.
Are within: Tests whether a geometry is within another. Returns 1 (true) if geometry a is completely inside geometry b. Only circle 1 is returned.
Cross: Returns 1 (true) if the supplied geometries have some, but not all, interior points in common and the actual crossing is of a lower dimension than the highest supplied geometry. For example, a line crossing a polygon will cross as a line (true). Two lines crossing will cross as a point (true). Two polygons cross as a polygon (false). In the picture, no circles will be returned.

Paraméterek

Címke	Név	Típus	Leírás
Extract features from	`INPUT`	[vector: any]	Input vector layer
Where the features (geometric predicate)	`PREDICATE`	[enumeration] [list] Default: [0]	Type of spatial relation the input feature should have with an intersect feature so that it could be selected. One or more of: 0 — intersect 1 — contain 2 — disjoint 3 — equal 4 — touch 5 — overlap 6 — are within 7 — cross If more than one condition is chosen, at least one of them (OR operation) has to be met for a feature to be extracted.
By comparing to the features from	`INTERSECT`	[vector: any]	Intersection vector layer
Extracted (location)	`OUTPUT`	[same as input] Default: `[Create temporary layer]`	Specify the output vector layer for the features that have the chosen spatial relationship(s) with one or more features in the comparison layer. One of: Create Temporary Layer (`TEMPORARY_OUTPUT`) Mentés fájlba… Save to Geopackage… Save to Database Table… The file encoding can also be changed here.

Eredmények

Címke	Név	Típus	Leírás
Extracted (location)	`OUTPUT`	[same as input]	Vector layer with features from the input layer that have the chosen spatial relationship(s) with one or more features in the comparison layer.

Python kód

Algorithm ID: qgis:extractbylocation

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.

27.1.20.4. Extract within distance 

Creates a new vector layer that only contains matching features from an input layer. Features are copied wherever they are within the specified maximum distance from the features in an additional reference layer.

Lásd még

Select within distance, Extract by location

Paraméterek

Címke	Név	Típus	Leírás
Extract features from	`INPUT`	[vector: any]	Input vector layer to copy features from
By comparing to the features from	`REFERENCE`	[vector: any]	Vector layer whose features closeness is used
Where the features are within	`DISTANCE`	[szám] Default: 100	The maximum distance around reference features to select input features within
Modify current selection by	`METHOD`	[felsorolás] Alapértelmezett: 0	How the selection of the algorithm should be managed. One of: 0 — creating new selection 1 — adding to current selection 2 — selecting within current selection 3 — removing from current selection
Extracted (location)	`OUTPUT`	[same as input] Default: `[Create temporary layer]`	Specify the output vector layer for the features that are within the set distance from reference features. One of: Create Temporary Layer (`TEMPORARY_OUTPUT`) Mentés fájlba… Save to Geopackage… Save to Database Table… The file encoding can also be changed here.

Eredmények

Címke	Név	Típus	Leírás
Extracted (location)	`OUTPUT`	[same as input]	Vector layer with features from the input layer matching the condition of distance from reference features

Python kód

Algorithm ID: native:extractwithindistance

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.

27.1.20.5. Szűrés geometriatípus szerint 

Filters features by their geometry type. Incoming features will be directed to different outputs based on whether they have a point, line or polygon geometry.

Paraméterek

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[vector: any]	Layer to evaluate

Eredmények

Címke	Név	Típus	Leírás
Point features Optional	`POINTS`	[vector: point]	Layer with points
Vonalelemek Optional	`LINES`	[vector: line]	Layer with lines
Polygon features Optional	`POLYGONS`	[vector: polygon]	Layer with polygons
Features with no geometry Optional	`NO_GEOMETRY`	[table]	Geometry-less vector layer

Python kód

Algorithm ID: native:filterbygeometry

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.

27.1.20.6. Random extract 

Takes a vector layer and generates a new one that contains only a subset of the features in the input layer.

The subset is defined randomly, based on feature IDs, using a percentage or count value to define the total number of features in the subset.

Lásd még

Random selection

Paraméterek

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[vector: any]	Source vector layer to select the features from
Módszer	`METHOD`	[felsorolás] Alapértelmezett: 0	Random selection methods. One of: 0 — Number of selected features 1 — Percentage of selected features
Number/percentage of selected features	`NUMBER`	[szám] Default: 10	Number or percentage of features to select
Extracted (random)	`OUTPUT`	[vector: any] Default: `[Create temporary layer]`	Specify the output vector layer for the randomly selected features. One of: Create Temporary Layer (`TEMPORARY_OUTPUT`) Mentés fájlba… Save to Geopackage… Save to Database Table… The file encoding can also be changed here.

Eredmények

Címke	Név	Típus	Leírás
Extracted (random)	`OUTPUT`	[same as input]	Vector layer containing randomly selected features from the input layer

Python kód

Algorithm ID: qgis:randomextract

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.

27.1.20.7. Random extract within subsets 

Takes a vector layer and generates a new one that contains only a subset of the features in the input layer.

The subset is defined randomly, based on feature IDs, using a percentage or count value to define the total number of features in the subset. The percentage/count value is not applied to the whole layer, but instead to each category. Categories are defined according to a given attribute.

Lásd még

Random selection within subsets

Paraméterek

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[vector: any]	Vector layer to select the features from
ID field	`FIELD`	[tablefield: any]	Category of the source vector layer to select the features from
Módszer	`METHOD`	[felsorolás] Alapértelmezett: 0	Random selection method. One of: 0 — Number of selected features 1 — Percentage of selected features
Number/percentage of selected features	`NUMBER`	[szám] Default: 10	Number or percentage of features to select
Extracted (random stratified)	`OUTPUT`	[same as input] Default: `[Create temporary layer]`	Specify the output vector layer for the randomly selected features. One of: Create Temporary Layer (`TEMPORARY_OUTPUT`) Mentés fájlba… Save to Geopackage… Save to Database Table… The file encoding can also be changed here.

Eredmények

Címke	Név	Típus	Leírás
Extracted (random stratified)	`OUTPUT`	[same as input]	Vector layer containing randomly selected features from the input layer

Python kód

Algorithm ID: qgis:randomextractwithinsubsets

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.

27.1.20.8. Random selection 

Takes a vector layer and selects a subset of its features. No new layer is generated by this algorithm.

The subset is defined randomly, based on feature IDs, using a percentage or count value to define the total number of features in the subset.

Default menu: Vector ► Research Tools

Lásd még

Random extract

Paraméterek

Címke

Név

Típus

Leírás

Bemeneti réteg

INPUT

[vector: any]

Vector layer for the selection

Módszer

METHOD

[felsorolás]

Alapértelmezett: 0

Random selection method. One of:

0 — Number of selected features
1 — Percentage of selected features

Number/percentage of selected features

NUMBER

[szám]

Default: 10

Number or percentage of features to select

Eredmények

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[same as input]	The input layer with features selected

Python kód

Algorithm ID: qgis:randomselection

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.

27.1.20.9. Random selection within subsets 

Takes a vector layer and selects a subset of its features. No new layer is generated by this algorithm.

The subset is defined randomly, based on feature IDs, using a percentage or count value to define the total number of features in the subset.

The percentage/count value is not applied to the whole layer, but instead to each category.

Categories are defined according to a given attribute, which is also specified as an input parameter for the algorithm.

No new outputs are created.

Default menu: Vector ► Research Tools

Lásd még

Random extract within subsets

Paraméterek

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[vector: any]	Vector layer to select features in
ID field	`FIELD`	[tablefield: any]	Category of the input layer to select the features from
Módszer	`METHOD`	[felsorolás] Alapértelmezett: 0	Random selection method. One of: 0 — Number of selected features 1 — Percentage of selected features
Number/percentage of selected features	`NUMBER`	[szám] Default: 10	Number or percentage of features to select

Eredmények

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[same as input]	The input layer with features selected

Python kód

Algorithm ID: qgis:randomselectionwithinsubsets

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.

27.1.20.10. Select by attribute 

Creates a selection in a vector layer.

The criteria for selecting features is based on the values of an attribute from the input layer.

Lásd még

Extract by attribute

Paraméterek

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[vector: any]	Vector layer to select features in
Selection attribute	`FIELD`	[tablefield: any]	Filtering field of the layer
Operator	`OPERATOR`	[felsorolás] Alapértelmezett: 0	Many different operators are available: 0 — = 1 — ≠ 2 — > 3 — >= 4 — < 5 — <= 6 — begins with 7 — contains 8 — is null 9 — is not null 10 — does not contain
Value Optional	`VALUE`	[karakterlánc]	Value to be evaluated
Modify current selection by	`METHOD`	[felsorolás] Alapértelmezett: 0	How the selection of the algorithm should be managed. One of: 0 — creating new selection 1 — adding to current selection 2 — removing from current selection 3 — selecting within current selection

Eredmények

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[same as input]	The input layer with features selected

Python kód

Algorithm ID: qgis:selectbyattribute

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.

27.1.20.11. Select by expression 

Creates a selection in a vector layer.

The criteria for selecting features is based on a QGIS expression. For more information about expressions see the Kifejezések.

Lásd még

Extract by expression

Paraméterek

Címke

Név

Típus

Leírás

Bemeneti réteg

INPUT

[vector: any]

Input vector layer

Expression

EXPRESSION

[expression]

Expression to filter the input layer

Modify current selection by

METHOD

[felsorolás]

Alapértelmezett: 0

How the selection of the algorithm should be managed. One of:

0 — creating new selection
1 — adding to current selection
2 — removing from current selection
3 — selecting within current selection

Eredmények

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[same as input]	The input layer with features selected

Python kód

Algorithm ID: qgis:selectbyexpression

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.

27.1.20.12. Select by location 

Creates a selection in a vector layer.

The criteria for selecting features is based on the spatial relationship between each feature and the features in an additional layer.

Default menu: Vector ► Research Tools

Lásd még

Extract by location, Select within distance

Exploring spatial relations

Geometric predicates are boolean functions used to determine the spatial relation a feature has with another by comparing whether and how their geometries share a portion of space.

Using the figure above, we are looking for the green circles by spatially comparing them to the orange rectangle feature. Available geometric predicates are:

Intersect: Tests whether a geometry intersects another. Returns 1 (true) if the geometries spatially intersect (share any portion of space - overlap or touch) and 0 if they don’t. In the picture above, this will return circles 1, 2 and 3.
Contain: Returns 1 (true) if and only if no points of b lie in the exterior of a, and at least one point of the interior of b lies in the interior of a. In the picture, no circle is returned, but the rectangle would be if you would look for it the other way around, as it contains circle 1 completely. This is the opposite of are within.
Disjoint: Returns 1 (true) if the geometries do not share any portion of space (no overlap, not touching). Only circle 4 is returned.
Equal: Returns 1 (true) if and only if geometries are exactly the same. No circles will be returned.
Touch: Tests whether a geometry touches another. Returns 1 (true) if the geometries have at least one point in common, but their interiors do not intersect. Only circle 3 is returned.
Overlap: Tests whether a geometry overlaps another. Returns 1 (true) if the geometries share space, are of the same dimension, but are not completely contained by each other. Only circle 2 is returned.
Are within: Tests whether a geometry is within another. Returns 1 (true) if geometry a is completely inside geometry b. Only circle 1 is returned.
Cross: Returns 1 (true) if the supplied geometries have some, but not all, interior points in common and the actual crossing is of a lower dimension than the highest supplied geometry. For example, a line crossing a polygon will cross as a line (true). Two lines crossing will cross as a point (true). Two polygons cross as a polygon (false). In the picture, no circles will be returned.

Paraméterek

Címke	Név	Típus	Leírás
Select features from	`INPUT`	[vector: any]	Input vector layer
Where the features (geometric predicate)	`PREDICATE`	[enumeration] [list] Default: [0]	Type of spatial relation the input feature should have with an intersect feature so that it could be selected. One or more of: 0 — intersect 1 — contain 2 — disjoint 3 — equal 4 — touch 5 — overlap 6 — are within 7 — cross If more than one condition is chosen, at least one of them (OR operation) has to be met for a feature to be extracted.
By comparing to the features from	`INTERSECT`	[vector: any]	Intersection vector layer
Modify current selection by	`METHOD`	[felsorolás] Alapértelmezett: 0	How the selection of the algorithm should be managed. One of: 0 — creating new selection 1 — adding to current selection 2 — selecting within current selection 3 — removing from current selection

Eredmények

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[same as input]	The input layer with features selected

Python kód

Algorithm ID: qgis:selectbylocation

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.

27.1.20.13. Select within distance 

creates a selection in a vector layer. Features are selected wherever they are within the specified maximum distance from the features in an additional reference layer.

Lásd még

Extract within distance, Select by location

Paraméterek

Címke	Név	Típus	Leírás
Select features from	`INPUT`	[vector: any]	Input vector layer to select features from
By comparing to the features from	`REFERENCE`	[vector: any]	Vector layer whose features closeness is used
Where the features are within	`DISTANCE`	[szám] Default: 100	The maximum distance around reference features to select input features
Modify current selection by	`METHOD`	[felsorolás] Alapértelmezett: 0	How the selection of the algorithm should be managed. One of: 0 — creating new selection 1 — adding to current selection 2 — selecting within current selection 3 — removing from current selection

Eredmények

Címke	Név	Típus	Leírás
Bemeneti réteg	`INPUT`	[same as input]	The input layer with features selected

Python kód

Algorithm ID: native:selectwithindistance

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

Az algoritmus azonosító akkor jelenik meg, ha az egérmutatót az algoritmus fölé viszi a Feldolgozás eszköztáron. A paraméterszótár tartalmazza a paraméter NAME-eket és érékeket. A feldolgozási algoritmusok Python konzolról történő futtatásával kapcsolatos részletekért lásd a Using processing algorithms from the console fejezetet.