24.1.17. Vector selection

24.1.17.1. 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.

Ver também

Select by attribute

24.1.17.1.1. Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vector: any]

Layer to extract features from.

Selection attribute

CAMPO

[tablefield: any]

Filtering field of the layer

Operator

OPERATOR

[enumeration]

Padrão: 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

Opcional

VALOR

[string]

Value to be evaluated

Extracted (attribute)

SAÍDA

[same as input]

Default: [Create Temporary Layer]

Specify the output vector layer for matching features. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Salvar para Arquivo…

  • Salvar para Geopackage…

  • Salvar para Tabela PostGIS…

A codificação do arquivo também pode ser alterada aqui.

Extracted (non-matching)

FAIL_OUTPUT

[same as input]

Default: [Skip output]

Specify the output vector layer for non-matching features. One of:

  • Ignorar Saída

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Salvar para Arquivo…

  • Salvar para Geopackage…

  • Salvar para Tabela PostGIS…

24.1.17.1.2. Saídas

Etiqueta

Nome

Tipo

Descrição

Extracted (attribute)

SAÍDA

[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

24.1.17.1.3. Python code

Algorithm ID: qgis:extractbyattribute

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 Usando os algoritmos do processamento a partir do Terminal Python. for details on how to run processing algorithms from the Python console.

24.1.17.2. 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 Expressões.

Ver também

Select by expression

24.1.17.2.1. Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vector: any]

Camada vetorial de entrada

Expressão

EXPRESSÃO

[expression]

Expression to filter the vector layer

Matching features

SAÍDA

[same as input]

Default: [Create Temporary Layer]

Specify the output vector layer for matching features. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Salvar para Arquivo…

  • Salvar para Geopackage…

  • Salvar para Tabela PostGIS…

A codificação do arquivo também pode ser alterada aqui.

Non-matching

FAIL_OUTPUT

[same as input]

Default: [Skip output]

Specify the output vector layer for non-matching features. One of:

  • Ignorar Saída

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Salvar para Arquivo…

  • Salvar para Geopackage…

  • Salvar para Tabela PostGIS…

24.1.17.2.2. Saídas

Etiqueta

Nome

Tipo

Descrição

Matching features

SAÍDA

[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

24.1.17.2.3. Python code

Algorithm ID: qgis:extractbyexpression

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 Usando os algoritmos do processamento a partir do Terminal Python. for details on how to run processing algorithms from the Python console.

24.1.17.3. 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.

../../../../_images/selectbylocation.png

Fig. 24.94 In this example, the dataset from which we want to select (the source vector layer) consists of the green circles, the orange rectangle is the dataset that it is being compared to (the intersection vector layer).

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 select circles 1, 2 and 3.

Contain

Retorna 1 (verdadeiro) se e somente se nenhum ponto de b estiver no exterior de a e pelo menos um ponto do interior de b estiver no interior de a. Na imagem, nenhum círculo é selecionado, mas o retângulo seria se você o selecionasse ao contrário, pois ele contém um círculo completamente. Este é o oposto de are within.

Disjoint

Returns 1 (true) if the geometries do not share any portion of space (no overlap, not touching). Only circle 4 is selected.

Igual

Retorna 1 (verdadeiro) se e somente se as geometrias forem exatamente iguais. Nenhum círculo será selecionado.

Touch

Testa se uma geometria toca em outra. Retorna 1 (verdadeiro) se as geometrias tiverem pelo menos um ponto em comum, mas seus interiores não se cruzam. Somente o círculo 3 está selecionado.

Overlap

Testa se uma geometria sobrepõe outra. Retorna 1 (verdadeiro) se as geometrias compartilharem espaço, têm a mesma dimensão, mas não estão completamente contidas uma na outra. Somente o círculo 2 está selecionado.

Are within

Tests whether a geometry is within another. Returns 1 (true) if geometry a is completely inside geometry b. Only circle 1 is selected.

Cross

Retorna 1 (verdadeiro) se as geometrias fornecidas tiverem alguns pontos internos em comum, mas não todos, e o cruzamento real tiver uma dimensão menor que a maior geometria fornecida. Por exemplo, uma linha cruzando um polígono cruzará como uma linha (selecionada). O cruzamento de duas linhas cruzará como um ponto (selecionado). Dois polígonos cruzam como um polígono (não selecionado).

24.1.17.3.1. Parâmetros

Etiqueta

Nome

Tipo

Descrição

Extract features from

ENTRADA

[vector: any]

Camada vetorial de entrada

Where the features (geometric predicate)

PREDICATE

[enumeration] [list]

Padrão: [0]

Spatial condition for the selection. 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)

SAÍDA

[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)

  • Salvar para Arquivo…

  • Salvar para Geopackage…

  • Salvar para Tabela PostGIS…

24.1.17.3.2. Saídas

Etiqueta

Nome

Tipo

Descrição

Extracted (location)

SAÍDA

[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.

24.1.17.3.3. Python code

Algorithm ID: qgis:extractbylocation

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 Usando os algoritmos do processamento a partir do Terminal Python. for details on how to run processing algorithms from the Python console.

24.1.17.4. 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.

Ver também

Seleção aleatória

24.1.17.4.1. Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vector: any]

Source vector layer to select the features from

Método

MÉTODO

[enumeration]

Padrão: 0

Random selection methods. One of:

  • 0 — Number of selected features

  • 1 — Percentage of selected features

Number/percentage of selected features

NÚMERO

[number]

Padrão: 10

Number or percentage of features to select

Extracted (random)

SAÍDA

[vector: any]

Default: [Create temporary layer]

Specify the output vector layer for the randomly selected features. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Salvar para Arquivo…

  • Salvar para Geopackage…

  • Salvar para Tabela PostGIS…

Vector layer containing randomly selected features

24.1.17.4.2. Saídas

Etiqueta

Nome

Tipo

Descrição

Extracted (random)

SAÍDA

[same as input]

Vector layer containing randomly selected features from the input layer

24.1.17.4.3. Python code

Algorithm ID: qgis:randomextract

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 Usando os algoritmos do processamento a partir do Terminal Python. for details on how to run processing algorithms from the Python console.

24.1.17.5. 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.

24.1.17.5.1. Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vector: any]

Vector layer to select the features from

ID field

CAMPO

[tablefield: any]

Category of the source vector layer to select the features from

Método

MÉTODO

[enumeration]

Padrão: 0

Random selection method. One of:

  • 0 — Number of selected features

  • 1 — Percentage of selected features

Number/percentage of selected features

NÚMERO

[number]

Padrão: 10

Number or percentage of features to select

Extracted (random stratified)

SAÍDA

[same as input]

Default: [Create temporary layer]

Specify the output vector layer for the randomly selected features. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Salvar para Arquivo…

  • Salvar para Geopackage…

  • Salvar para Tabela PostGIS…

A codificação do arquivo também pode ser alterada aqui.

24.1.17.5.2. Saídas

Etiqueta

Nome

Tipo

Descrição

Extracted (random stratified)

SAÍDA

[same as input]

Vector layer containing randomly selected features from the input layer

24.1.17.5.3. Python code

Algorithm ID: qgis:randomextractwithinsubsets

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 Usando os algoritmos do processamento a partir do Terminal Python. for details on how to run processing algorithms from the Python console.

24.1.17.6. Seleção aleatória

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

Ver também

Random extract

24.1.17.6.1. Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vector: any]

Vector layer for the selection

Método

MÉTODO

[enumeration]

Padrão: 0

Random selection method. One of:

  • 0 — Number of selected features

  • 1 — Percentage of selected features

Number/percentage of selected features

NÚMERO

[number]

Padrão: 10

Number or percentage of features to select

24.1.17.6.2. Saídas

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[same as input]

The input layer with features selected

24.1.17.6.3. Python code

Algorithm ID: qgis:randomselection

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 Usando os algoritmos do processamento a partir do Terminal Python. for details on how to run processing algorithms from the Python console.

24.1.17.7. 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

24.1.17.7.1. Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vector: any]

Vector layer to select features in

ID field

CAMPO

[tablefield: any]

Category of the input layer to select the features from

Método

MÉTODO

[enumeration]

Padrão: 0

Random selection method. One of:

  • 0 — Number of selected features

  • 1 — Percentage of selected features

Number/percentage of selected features

NÚMERO

[number]

Padrão: 10

Number or percentage of features to select

24.1.17.7.2. Saídas

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[same as input]

The input layer with features selected

24.1.17.7.3. Python code

Algorithm ID: qgis:randomselectionwithinsubsets

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 Usando os algoritmos do processamento a partir do Terminal Python. for details on how to run processing algorithms from the Python console.

24.1.17.8. 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.

Ver também

Extract by attribute

24.1.17.8.1. Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vector: any]

Vector layer to select features in

Selection attribute

CAMPO

[tablefield: any]

Filtering field of the layer

Operator

OPERATOR

[enumeration]

Padrão: 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

Opcional

VALOR

[string]

Value to be evaluated

Modify current selection by

MÉTODO

[enumeration]

Padrão: 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

24.1.17.8.2. Saídas

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[same as input]

The input layer with features selected

24.1.17.8.3. Python code

Algorithm ID: qgis:selectbyattribute

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 Usando os algoritmos do processamento a partir do Terminal Python. for details on how to run processing algorithms from the Python console.

24.1.17.9. 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 Expressões.

Ver também

Extract by expression

24.1.17.9.1. Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vector: any]

Camada vetorial de entrada

Expressão

EXPRESSÃO

[expression]

Expression to filter the input layer

Modify current selection by

MÉTODO

[enumeration]

Padrão: 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

24.1.17.9.2. Saídas

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[same as input]

The input layer with features selected

24.1.17.9.3. Python code

Algorithm ID: qgis:selectbyexpression

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 Usando os algoritmos do processamento a partir do Terminal Python. for details on how to run processing algorithms from the Python console.

24.1.17.10. Selecionar pela localização

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.

../../../../_images/selectbylocation.png

Fig. 24.95 In this example, the dataset from which we want to select (the source vector layer) consists of the green circles, the orange rectangle is the dataset that it is being compared to (the intersection vector layer).

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 select circles 1, 2 and 3.

Contain

Retorna 1 (verdadeiro) se e somente se nenhum ponto de b estiver no exterior de a e pelo menos um ponto do interior de b estiver no interior de a. Na imagem, nenhum círculo é selecionado, mas o retângulo seria se você o selecionasse ao contrário, pois ele contém um círculo completamente. Este é o oposto de are within.

Disjoint

Returns 1 (true) if the geometries do not share any portion of space (no overlap, not touching). Only circle 4 is selected.

Igual

Retorna 1 (verdadeiro) se e somente se as geometrias forem exatamente iguais. Nenhum círculo será selecionado.

Touch

Testa se uma geometria toca em outra. Retorna 1 (verdadeiro) se as geometrias tiverem pelo menos um ponto em comum, mas seus interiores não se cruzam. Somente o círculo 3 está selecionado.

Overlap

Testa se uma geometria sobrepõe outra. Retorna 1 (verdadeiro) se as geometrias compartilharem espaço, têm a mesma dimensão, mas não estão completamente contidas uma na outra. Somente o círculo 2 está selecionado.

Are within

Tests whether a geometry is within another. Returns 1 (true) if geometry a is completely inside geometry b. Only circle 1 is selected.

Cross

Retorna 1 (verdadeiro) se as geometrias fornecidas tiverem alguns pontos internos em comum, mas não todos, e o cruzamento real tiver uma dimensão menor que a maior geometria fornecida. Por exemplo, uma linha cruzando um polígono cruzará como uma linha (selecionada). O cruzamento de duas linhas cruzará como um ponto (selecionado). Dois polígonos cruzam como um polígono (não selecionado).

Default menu: Vector ► Research Tools

Ver também

Extract by location

24.1.17.10.1. Parâmetros

Etiqueta

Nome

Tipo

Descrição

Select features from

ENTRADA

[vector: any]

Camada vetorial de entrada

Where the features (geometric predicate)

PREDICATE

[enumeration] [list]

Padrão: [0]

Spatial condition for the selection. 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

MÉTODO

[enumeration]

Padrão: 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

24.1.17.10.2. Saídas

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[same as input]

The input layer with features selected

24.1.17.10.3. Python code

Algorithm ID: qgis:selectbylocation

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 Usando os algoritmos do processamento a partir do Terminal Python. for details on how to run processing algorithms from the Python console.