25.1.19. Vector overlay

25.1.19.1. Clip

Clips a vector layer using the features of an additional polygon layer.

Only the parts of the features in the input layer that fall within the polygons of the overlay layer will be added to the resulting layer.

Aviso

Apenas modificação de geometria

This operation modifies only the features geometry. The attribute values of the features are not modified, although properties such as area or length of the features will be modified by the clipping operation. If such properties are stored as attributes, those attributes will have to be manually updated.

This algorithm uses spatial indexes on the providers, prepared geometries and apply a clipping operation if the geometry isn’t wholly contained by the mask geometry.

../../../../_images/clip3.png

Fig. 25.101 Clipping operation between a two-features input layer and a single feature overlay layer (left) - resulting features are moved for clarity (right)

caixa de seleção Allows features in-place modification of point, line, and polygon features

Default menu: Vector ► Geoprocessing Tools

Ver também

Interseção, Diferença

Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vetor: qualquer]

Layer containing the features to be clipped

Overlay layer

OVERLAY

[vetor: polígono]

Layer containing the clipping features

Clipped

SAÍDA

[same as input]

Padrão: [Criar camada temporária]

Specify the layer to contain the features from the input layer that are inside the overlay (clipping) layer. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Save to File…

  • Salvar para Geopackage…

  • Save to Database Table…

A codificação do arquivo também pode ser alterada aqui.

Saídas

Etiqueta

Nome

Tipo

Descrição

Clipped

SAÍDA

[same as input]

Layer containing features from the input layer split by the overlay layer.

Código Python

Algorithm ID: qgis:clip

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.

25.1.19.2. Diferença

Extracts features from the input layer that don’t fall within the boundaries of the overlay layer.

Input layer features that partially overlap the overlay layer feature(s) are split along the boundary of those feature(s) and only the portions outside the overlay layer features are retained.

Aviso

Apenas modificação de geometria

This operation modifies only the features geometry. The attribute values of the features are not modified, although properties such as area or length of the features will be modified by the clipping operation. If such properties are stored as attributes, those attributes will have to be manually updated.

../../../../_images/difference.png

Fig. 25.102 Difference operation between a two-features input layer and a single feature overlay layer (left) - resulting features are moved for clarity (right)

caixa de seleção Allows features in-place modification of point, line, and polygon features

Default menu: Vector ► Geoprocessing Tools

Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vetor: qualquer]

Layer to extract (parts of) features from.

Overlay layer

OVERLAY

[vetor: qualquer]

Layer containing the geometries that will be subtracted from the input layer geometries. It is expected to have at least as many dimensions (point: 0D, line: 1D, polygon: 2D, volume: 3D) as the input layer geometries.

Diferença

SAÍDA

[same as input]

Padrão: [Criar camada temporária]

Specify the layer to contain the (parts of) features from the input layer that are not inside the overlay layer. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Save to File…

  • Salvar para Geopackage…

  • Save to Database Table…

A codificação do arquivo também pode ser alterada aqui.

Saídas

Etiqueta

Nome

Tipo

Descrição

Diferença

SAÍDA

[same as input]

Layer containing (parts of) features from the input layer not overlapping the overlay layer.

Código Python

Algorithm ID: qgis:difference

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.

25.1.19.3. Extract/clip by extent

Cria uma nova camada vetorial que contém apenas feições que se enquadram em uma extensão especificada.

Quaisquer feições que cruzem a extensão serão incluídas.

../../../../_images/extractbyextent.png

Fig. 25.103 Extract operation between a three-feature input layer ‘a’ and a dashed extent (left) - resulting features with dashed extent for reference (right)

Ver também

Clip

Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vetor: qualquer]

Layer to extract (parts of) features from.

Extensão (xmin, xmax, ymin, ymax)

`` EXTENSÃO``

[extensão]

Extent for clipping.

Os métodos disponíveis são:

  • Calculate from layer…: uses extent of a layer loaded in the current project

  • Use map canvas extent

  • Desenhar na tela

  • Insira as coordenadas como xmin, xmax, ymin, ymax

Clip features to extent

CLIP

[boleano]

Padrão: Falso

If checked, output geometries will be automatically converted to multi geometries to ensure uniform output types. Moreover the geometries will be clipped to the extent chosen instead of taking the whole geometry as output.

../../../../_images/extractbyextent_clip.png

Fig. 25.104 Extract operation between a three-feature input layer ‘a’ and a dashed extent (left) - resulting features with dashed extent for reference (right)

Extraído

SAÍDA

[same as input]

Padrão: [Criar camada temporária]

Specify the layer to contain the features from the input layer that are inside the clip extent. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Save to File…

  • Salvar para Geopackage…

  • Save to Database Table…

A codificação do arquivo também pode ser alterada aqui.

Saídas

Etiqueta

Nome

Tipo

Descrição

Extraído

SAÍDA

[same as input]

Layer containing the clipped features.

Código Python

Algorithm ID: qgis:extractbyextent

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.

25.1.19.4. Interseção

Extracts the portions of features from the input layer that overlap features in the overlay layer.

Features in the intersection layer are assigned the attributes of the overlapping features from both the input and overlay layers.

Aviso

Apenas modificação de geometria

This operation modifies only the features geometry. The attribute values of the features are not modified, although properties such as area or length of the features will be modified by the clipping operation. If such properties are stored as attributes, those attributes will have to be manually updated.

../../../../_images/intersection.png

Fig. 25.105 The intersection operation: A two-features input layer and a single feature overlay layer (left) - resulting features are moved for clarity (right)

Default menu: Vector ► Geoprocessing Tools

Ver também

Clip, Diferença

Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vetor: qualquer]

Layer to extract (parts of) features from.

Overlay layer

OVERLAY

[vetor: qualquer]

Layer containing the features to check for overlap. Its features’ geometry is expected to have at least as many dimensions (point: 0D, line: 1D, polygon: 2D, volume: 3D) as the input layer’s.

Input fields to keep (leave empty to keep all fields)

Opcional

INPUT_FIELDS

[tablefield: any] [list]

Padrão: Nenhum

Field(s) of the input layer to keep in the output. If no fields are chosen all fields are taken.

Overlay fields to keep (leave empty to keep all fields)

Opcional

OVERLAY_FIELDS

[tablefield: any] [list]

Padrão: Nenhum

Field(s) of the overlay layer to keep in the output. If no fields are chosen all fields are taken.

Overlay fields prefix

Opcional

OVERLAY_FIELDS_PREFIX

[string]

Prefix to add to the field names of the intersect layer’s fields to avoid name collisions with fields in the input layer.

Intersecção

SAÍDA

[same as input]

Padrão: [Criar camada temporária]

Specify the layer to contain (the parts of) the features from the input layer that overlap one or more features from the overlay layer. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Save to File…

  • Salvar para Geopackage…

  • Save to Database Table…

A codificação do arquivo também pode ser alterada aqui.

Saídas

Etiqueta

Nome

Tipo

Descrição

Intersecção

SAÍDA

[same as input]

Layer containing (parts of) features from the input layer that overlap the overlay layer.

Código Python

Algorithm ID: qgis:intersection

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.

25.1.19.5. Interseções de linha

Cria feições de ponto onde as linhas das duas camadas se cruzam.

../../../../_images/line_intersection.png

Fig. 25.106 Pontos de interseção

Default menu: Vector ► Analysis Tools

Parâmetros

Parâmetros básicos

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vetor: linha]

Input line layer.

camada de interseção*

`` INTERSEÇÃO``

[vetor: linha]

Layer to use to find line intersections.

Input fields to keep (leave empty to keep all fields)

Opcional

INPUT_FIELDS

[tablefield: any] [list]

Padrão: Nenhum

Field(s) of the input layer to keep in the output. If no fields are chosen all fields are taken.

Intersect fields to keep (leave empty to keep all fields)

Opcional

INTERSECT_FIELDS

[tablefield: any] [list]

Padrão: Nenhum

Field(s) of the intersect layer to keep in the output. If no fields are chosen all fields are taken.

Intersecção

SAÍDA

[vetor: ponto]

Padrão: [Criar camada temporária]

Specify the layer to contain the intersection points of the lines from the input and overlay layers. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Save to File…

  • Salvar para Geopackage…

  • Save to Database Table…

A codificação do arquivo também pode ser alterada aqui.

Parâmetros avançados

Etiqueta

Nome

Tipo

Descrição

Intersect fields prefix

Opcional

INTERSECT_FIELDS_PREFIX

[string]

Prefix to add to the field names of the intersect layer’s fields to avoid name collisions with fields in the input layer.

Saídas

Etiqueta

Nome

Tipo

Descrição

Interseções

SAÍDA

[vetor: ponto]

Point vector layer with the intersections.

Código Python

Algorithm ID: qgis:lineintersections

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.

25.1.19.6. Split with lines

Splits the lines or polygons in one layer using the lines in another layer to define the breaking points. Intersection between geometries in both layers are considered as split points.

Output will contain multi geometries for split features.

../../../../_images/split_with_lines.png

Fig. 25.107 Linhas divididas

caixa de seleção Allows features in-place modification of line and polygon features

Parâmetros

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vetor: linha, polígono]

Layer containing the lines or polygons to split.

Split layer

LINHAS

[vetor: linha]

Line layer whose lines are used to define the breaking points.

Dividir

SAÍDA

[same as input]

Padrão: [Criar camada temporária]

Specify the layer to contain the splitted (in case they are intersected by a line in the split layer) line/polygon features from the input layer. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Save to File…

  • Salvar para Geopackage…

  • Save to Database Table…

A codificação do arquivo também pode ser alterada aqui.

Saídas

Etiqueta

Nome

Tipo

Descrição

Dividir

SAÍDA

[same as input]

Output vector layer with split lines or polygons from input layer.

Código Python

Algorithm ID: qgis:splitwithlines

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.

25.1.19.7. Diferença simétrica

Creates a layer containing features from both the input and overlay layers but with the overlapping areas between the two layers removed.

The attribute table of the symmetrical difference layer contains attributes and fields from both the input and overlay layers.

Aviso

Apenas modificação de geometria

This operation modifies only the features geometry. The attribute values of the features are not modified, although properties such as area or length of the features will be modified by the clipping operation. If such properties are stored as attributes, those attributes will have to be manually updated.

../../../../_images/symmetrical_difference.png

Fig. 25.108 Symmetrical difference operation between a two-features input layer and a single feature overlay layer (left) - resulting features are moved for clarity (right)

Default menu: Vector ► Geoprocessing Tools

Ver também

Diferença, Clip, Interseção

Parâmetros

Parâmetros básicos

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vetor: qualquer]

Primeira camada para extrair (partes de) feições de.

Overlay layer

OVERLAY

[vetor: qualquer]

Second layer to extract (parts of) features from. Ideally the geometry type should be the same as input layer.

Diferença simétrica

SAÍDA

[same as input]

Padrão: [Criar camada temporária]

Specify the layer to contain (the parts of) the features from the input and overlay layers that do not overlap features from the other layer. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Save to File…

  • Salvar para Geopackage…

  • Save to Database Table…

A codificação do arquivo também pode ser alterada aqui.

Parâmetros avançados

Etiqueta

Nome

Tipo

Descrição

Overlay fields prefix

Opcional

OVERLAY_FIELDS_PREFIX

[string]

Prefix to add to the field names of the overlay layer’s fields to avoid name collisions with fields in the input layer.

Saídas

Etiqueta

Nome

Tipo

Descrição

Diferença simétrica

SAÍDA

[same as input]

Layer containing (parts of) features from each layer not overlapping the other layer.

Código Python

Algorithm ID: qgis:symmetricaldifference

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.

25.1.19.8. União

Checks overlaps between features within the input layer and creates separate features for overlapping and non-overlapping parts. The area of overlap will create as many identical overlapping features as there are features that participate in that overlap.

../../../../_images/union.png

Fig. 25.109 Union operation with a single input layer of three overlapping features (left) - resulting features are moved for clarity (right)

An overlay layer can also be used, in which case features from each layer are split at their overlap with features from the other one, creating a layer containing all the portions from both input and overlay layers. The attribute table of the union layer is filled with attribute values from the respective original layer for non-overlapping features, and attribute values from both layers for overlapping features.

../../../../_images/union_with_overlay.png

Fig. 25.110 Union operation between a two-features input layer and a single feature overlay layer (left) - resulting features are moved for clarity (right)

Nota

For union(A,B) algorithm, if there are overlaps among geometries of layer A or among geometries of layer B, these are not resolved: you need to do union(union(A,B)) to resolve all overlaps, i.e. run single layer union(X) on the produced result X=union(A,B).

Default menu: Vector ► Geoprocessing Tools

Ver também

Clip, Diferença, Interseção

Parâmetros

Parâmetros básicos

Etiqueta

Nome

Tipo

Descrição

Camada de entrada

ENTRADA

[vetor: qualquer]

Input vector layer to split at any intersections.

Overlay layer

Opcional

OVERLAY

[vetor: qualquer]

Layer that will be combined to the first one. Ideally the geometry type should be the same as input layer.

União

SAÍDA

[same as input]

Padrão: [Criar camada temporária]

Specify the layer to contain the (split and duplicated) features from the input layer and the overlay layer. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • Save to File…

  • Salvar para Geopackage…

  • Save to Database Table…

A codificação do arquivo também pode ser alterada aqui.

Parâmetros avançados

Etiqueta

Nome

Tipo

Descrição

Overlay fields prefix

Opcional

OVERLAY_FIELDS_PREFIX

[string]

Prefix to add to the field names of the overlay layer’s fields to avoid name collisions with fields in the input layer.

Saídas

Etiqueta

Nome

Tipo

Descrição

União

SAÍDA

[same as input]

Layer containing all the overlapping and non-overlapping parts from the processed layer(s).

Código Python

Algorithm ID: qgis:union

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.