27.1.16. Vector creation

27.1.16.1. Array of offset (parallel) lines

Creates copies of line features in a layer, by creating multiple offset versions of each feature. Each new version is incrementally offset by a specified distance.

Positive distance will offset lines to the left, and negative distances will offset them to the right.

../../../../_images/offset_lines_array.png

图 27.36 In blue the source layer, in red the offset one

checkbox Allows features in-place modification of line features

参数

Basic parameters

标注

名称

类型

描述

输入图层

INPUT

[vector: line]

Input line vector layer to use for the offsets.

Number of features to create

COUNT

[number dataDefine]

Default: 10

Number of offset copies to generate for each feature

Offset step distance

OFFSET

[number dataDefine]

默认值:1.0

Distance between two consecutive offset copies

Offset lines

OUTPUT

[vector: line]

Default: [Create temporary layer]

Specify the output line layer with offset features. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

  • Append to Layer…

文件编码也可以在此更改。

Advanced parameters

标注

名称

类型

描述

Segments

SEGMENTS

[数字]

Default: 8

Number of line segments to use to approximate a quarter circle when creating rounded offsets

Join style

JOIN_STYLE

[enumeration]

Default: 0

Specify whether round, miter or beveled joins should be used when offsetting corners in a line. One of:

  • 0 --- Round

  • 1 --- Miter

  • 2 --- Bevel

../../../../_images/buffer_join_style.png

图 27.37 Round, miter, and bevel join styles

Miter limit

MITER_LIMIT

[数字]

Default: 2.0

Sets the maximum distance from the offset geometry to use when creating a mitered join as a factor of the offset distance (only applicable for miter join styles). Minimum: 1.0

../../../../_images/buffer_miter_limit.png

图 27.38 A 10m buffer with a limit of 2 and a 10m buffer with a limit of 1

输出

标注

名称

类型

描述

Offset lines

OUTPUT

[vector: line]

Output line layer with offset features. The original features are also copied.

Python代码

Algorithm ID: native:arrayoffsetlines

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.2. Array of translated features

Creates copies of features in a layer by creating multiple translated versions of each. Each copy is incrementally displaced by a preset amount in the X, Y and/or Z axis.

M values present in the geometry can also be translated.

../../../../_images/translate_array.png

图 27.39 Input layers in blue tones, output layers with translated features in red tones

checkbox Allows features in-place modification of point, line, and polygon features

参数

标注

名称

类型

描述

输入图层

INPUT

[vector: any]

Input vector layer to translate

Number of features to create

COUNT

[number dataDefine]

Default: 10

Number of copies to generate for each feature

Step distance (x-axis)

DELTA_X

[number dataDefine]

Default: 0.0

Displacement to apply on the X axis

Step distance (y-axis)

DELTA_Y

[number dataDefine]

Default: 0.0

Displacement to apply on the Y axis

Step distance (z-axis)

DELTA_Z

[number dataDefine]

Default: 0.0

Displacement to apply on the Z axis

Step distance (m values)

DELTA_M

[number dataDefine]

Default: 0.0

Displacement to apply on M

Translated

OUTPUT

[same as input]

Default: [Create temporary layer]

Output vector layer with translated (moved) copies of the features. The original features are also copied. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

  • Append to Layer…

文件编码也可以在此更改。

输出

标注

名称

类型

描述

Translated

OUTPUT

[same as input]

Output vector layer with translated (moved) copies of the features. The original features are also copied.

Python代码

Algorithm ID: native:arraytranslatedfeatures

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.3. Create grid

Creates a vector layer with a grid covering a given extent. Grid cells can have different shapes:

../../../../_images/create_grid.png

图 27.40 Different grid cell shapes

The size of each element in the grid is defined using a horizontal and vertical spacing.

The CRS of the output layer must be defined.

The grid extent and the spacing values must be expressed in the coordinates and units of this CRS.

Default menu: Vector ► Research Tools

参数

标注

名称

类型

描述

Grid type

TYPE

[enumeration]

Default: 0

Shape of the grid. One of:

  • 0 --- Point

  • 1 --- Line

  • 2 --- Rectangle (polygon)

  • 3 --- Diamond (polygon)

  • 4 --- Hexagon (polygon)

Grid extent

EXTENT

[范围]

Extent of the grid

Available methods are:

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

  • Calculate from layout map…: uses extent of a layout map item in the active project

  • Calculate from bookmark…: uses extent of a saved bookmark

  • Use map canvas extent

  • Draw on canvas: click and drag a rectangle delimiting the area to take into account

  • Enter the coordinates as xmin, xmax, ymin, ymax

Horizontal spacing

HSPACING

[数字]

默认值:1.0

Size of a grid cell on the X-axis

Vertical spacing

VSPACING

[数字]

默认值:1.0

Size of a grid cell on the Y-axis

Horizontal overlay

HOVERLAY

[数字]

Default: 0.0

Overlay distance between two consecutive grid cells on the X-axis

Vertical overlay

VOVERLAY

[数字]

Default: 0.0

Overlay distance between two consecutive grid cells on the Y-axis

Grid CRS

CRS

[crs]

Default: Project CRS

Coordinate reference system to apply to the grid

Grid

OUTPUT

[vector: any]

Default: [Create temporary layer]

Resulting vector grid layer. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

输出

标注

名称

类型

描述

Grid

OUTPUT

[vector: any]

Resulting vector grid layer. The output geometry type (point, line or polygon) depends on the Grid type.

Python代码

Algorithm ID: native:creategrid

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.4. Create points layer from table

Creates points layer from a table with columns that contain coordinates fields.

Besides X and Y coordinates you can also specify Z and M fields.

参数

标注

名称

类型

描述

输入图层

INPUT

[vector: any]

Input vector layer or a table.

X field

XFIELD

[tablefield: any]

Field containing the X coordinate

Y field

YFIELD

[tablefield: any]

Field containing the Y coordinate

Z field

可选

ZFIELD

[tablefield: any]

Field containing the Z coordinate

M field

可选

MFIELD

[tablefield: any]

Field containing the M value

Target CRS

TARGET_CRS

[crs]

Default: EPSG:4326

Coordinate reference system to use for layer. The provided coordinates are assumed to be compliant.

Points from table

OUTPUT

[vector: point]

Default: [Create temporary layer]

Specify the resulting point layer. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

输出

标注

名称

类型

描述

Points from table

OUTPUT

[vector: point]

The resulting point layer

Python代码

Algorithm ID: native:createpointslayerfromtable

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.5. Generate points (pixel centroids) along line

Generates a point vector layer from an input raster and line layer.

The points correspond to the pixel centroids that intersect the line layer.

../../../../_images/points_centroids.png

图 27.41 Points of the pixel centroids

参数

标注

名称

类型

描述

Raster layer

INPUT_RASTER

[栅格]

Input raster layer

Vector layer

INPUT_VECTOR

[vector: line]

Input line vector layer

Points along line

OUTPUT

[vector: point]

Default: [Create temporary layer]

Resulting point layer with pixel centroids. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

输出

标注

名称

类型

描述

Points along line

OUTPUT

[vector: point]

Resulting point layer with pixel centroids

Python代码

Algorithm ID: qgis:generatepointspixelcentroidsalongline

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.6. Generate points (pixel centroids) inside polygon

Generates a point vector layer from an input raster and polygon layer.

The points correspond to the pixel centroids that intersect the polygon layer.

../../../../_images/points_centroids_polygon.png

图 27.42 Points of the pixel centroids

参数

标注

名称

类型

描述

Raster layer

INPUT_RASTER

[栅格]

Input raster layer

Vector layer

INPUT_VECTOR

[vector: polygon]

Input polygon vector layer

Points inside polygons

OUTPUT

[vector: point]

Default: [Create temporary layer]

Resulting point layer of pixel centroids. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

输出

标注

名称

类型

描述

Points inside polygons

OUTPUT

[vector: point]

Resulting point layer of pixel centroids

Python代码

Algorithm ID: native:generatepointspixelcentroidsinsidepolygons

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.7. Import geotagged photos

Creates a point layer corresponding to the geotagged locations from JPEG images from a source folder.

The point layer will contain a single PointZ feature per input file from which the geotags could be read. Any altitude information from the geotags will be used to set the point's Z value.

Besides longitude and latitude also altitude, direction and timestamp information, if present in the photo, will be added to the point as attributes.

参数

标注

名称

类型

描述

Input folder

FOLDER

[folder]

Path to the source folder containing the geotagged photos

Scan recursively

RECURSIVE

[boolean]

Default: False

If checked, the folder and its subfolders will be scanned

Photos

可选

OUTPUT

[vector: point]

Default: [Create temporary layer]

Specify the point vector layer for the geotagged photos. One of:

  • Skip Output

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

Invalid photos table

可选

INVALID

[table]

Default: [Skip output]

Specify the table of unreadable or non-geotagged photos. One of:

  • Skip Output

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

输出

标注

名称

类型

描述

Photos

OUTPUT

[vector: point]

Point vector layer with geotagged photos. The form of the layer is automatically filled with paths and photo previews settings.

Invalid photos table

可选

INVALID

[table]

Table of unreadable or non-geotagged photos can also be created.

Python代码

Algorithm ID: native:importphotos

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.8. Points to path

Converts a point layer to a line layer, by joining points in an order defined by an expression or a field in the input point layer.

Points can be grouped by a field or an expression to distinguish line features.

In addition to the line vector layer, a text file is output that describes the resulting line as a start point and a sequence of bearings / directions (relative to azimuth) and distances.

参数

标注

名称

类型

描述

Input point layer

INPUT

[vector: point]

Input point vector layer

Create closed paths

CLOSE_PATH

[boolean]

Default: False

If checked, the first and last points of the line will be connected and close the generated path

Order expression

可选

ORDER_EXPRESSION

[expression]

Field or expression providing the order to connect the points in the path. If not set, the feature ID ($id) is used.

Sort text containing numbers naturally

可选

NATURAL_SORT

[boolean]

Default: False

If checked, naturally sorts the features based on the provided expression (i.e., 'a9' < 'a10').

Path group expression

可选

GROUP_EXPRESSION

[expression]

Point features of the same value in the field or expression will be grouped in the same line. If not set, a single path is drawn with all the input points.

Paths

OUTPUT

[vector: line]

Default: [Create temporary layer]

Specify the line vector layer of the path. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

Directory for text output

可选

OUTPUT_TEXT_DIR

[folder]

Default: [Skip output]

Specify the directory that will contain the description files of points and paths. One of:

  • Skip Output

  • Save to a Temporary Directory

  • Save to Directory

输出

标注

名称

类型

描述

Paths

OUTPUT

[vector: line]

Line vector layer of the path

Directory for text output

OUTPUT_TEXT_DIR

[folder]

Directory containing description files of points and paths

Python代码

Algorithm ID: native:pointstopath

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.9. Random points along line

Creates a new point layer, with points placed on the lines of another layer.

For each line in the input layer, a given number of points is added to the resulting layer. The procedure for adding a point is to:

  1. randomly select a line feature from the input layer

  2. if the feature is multi-part, randomly select a part of it

  3. randomly select a segment of that line

  4. randomly select a position on that segment.

The procedure means that curved parts of the lines (with relatively short segments) will get more points than straight parts (with relatively long segments), as demonstrated in the illustration below, where the output of the Random points along lines algorithm can be compared with the output of the Random points on lines algorithm (that produces points with an, on average, even distribution along the lines).

../../../../_images/randompointsalonglines_illustration.png

图 27.43 Example algorithm output. Left: Random points along line, right: Random points on lines

A minimum distance can be specified, to avoid points being too close to each other.

参数

标注

名称

类型

描述

Input point layer

INPUT

[vector: line]

Input line vector layer

Number of points

POINTS_NUMBER

[数字]

Default: 1

Number of points to create

Minimum distance between points

MIN_DISTANCE

[数字]

Default: 0.0

The minimum distance between points

Random points

OUTPUT

[vector: point]

Default: [Create temporary layer]

The output random points. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

输出

标注

名称

类型

描述

Random points

OUTPUT

[vector: point]

The output random points layer.

Python代码

Algorithm ID: qgis:qgisrandompointsalongline

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.10. Random points in extent

Creates a new point layer with a given number of random points, all of them within a given extent.

A distance factor can be specified, to avoid points being too close to each other. If the minimum distance between points makes it impossible to create new points, either distance can be decreased or the maximum number of attempts may be increased.

Default menu: Vector ► Research Tools

参数

Basic parameters

标注

名称

类型

描述

Input extent

EXTENT

[范围]

Map extent for the random points

Available methods are:

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

  • Calculate from layout map…: uses extent of a layout map item in the active project

  • Calculate from bookmark…: uses extent of a saved bookmark

  • Use map canvas extent

  • Draw on canvas: click and drag a rectangle delimiting the area to take into account

  • Enter the coordinates as xmin, xmax, ymin, ymax

Number of points

POINTS_NUMBER

[数字]

Default: 1

Number of point to create

Minimum distance between points

MIN_DISTANCE

[数字]

Default: 0.0

The minimum distance between points

Target CRS

TARGET_CRS

[crs]

Default: Project CRS

CRS of the random points layer

Random points

OUTPUT

[vector: point]

Default: [Create temporary layer]

The output random points. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

Advanced parameters

标注

名称

类型

描述

Maximum number of search attempts given the minimum distance

MAX_ATTEMPTS

[数字]

Default: 200

Maximum number of attempts to place the points

输出

标注

名称

类型

描述

Random points

OUTPUT

[vector: point]

The output random points layer.

Python代码

Algorithm ID: native:randompointsinextent

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.11. Random points in layer bounds

Creates a new point layer with a given number of random points, all of them within the extent of a given layer.

A minimum distance can be specified, to avoid points being too close to each other.

Default menu: Vector ► Research Tools

参数

标注

名称

类型

描述

输入图层

INPUT

[vector: polygon]

Input polygon layer defining the area

Number of points

POINTS_NUMBER

[数字]

Default: 1

Number of points to create

Minimum distance between points

MIN_DISTANCE

[数字]

Default: 0.0

The minimum distance between points

Random points

OUTPUT

[vector: point]

Default: [Create temporary layer]

The output random points. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

输出

标注

名称

类型

描述

Random points

OUTPUT

[vector: point]

The output random points layer.

Python代码

Algorithm ID: qgis:randompointsinlayerbounds

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.12. Random points in polygons

Creates a point layer with points placed inside the polygons of another layer.

For each feature (polygon / multi-polygon) geometry in the input layer, the given number of points is added to the result layer.

Per feature and global minimum distances can be specified in order to avoid points being too close in the output point layer. If a minimum distance is specified, it may not be possible to generate the specified number of points for each feature. The total number of generated points and missed points are available as output from the algorithm.

The illustration below shows the effect of per feature and global minimum distances and zero/non-zero minimum distances (generated with the same seed, so at least the first point generated will be the same).

../../../../_images/randompointsinpolygons_mindistance.png

图 27.44 Ten points per polygon feature, left: min. distances = 0, middle: min.distances = 1, right: min. distance = 1, global min. distance = 0

The maximum number of tries per point can be specified. This is only relevant for non-zero minimum distance.

A seed for the random number generator can be provided, making it possible to get identical random number sequences for different runs of the algorithm.

The attributes of the polygon feature on which a point was generated can be included (Include polygon attributes).

If you want approximately the same point density for all the features, you can data-define the number of points using the area of the polygon feature geometry.

参数

Basic parameters

标注

名称

类型

描述

Input polygon layer

INPUT

[vector: line]

Input polygon vector layer

Number of points for each feature

POINTS_NUMBER

[number dataDefine]

Default: 1

Number of points to create

Minimum distance between points

可选

MIN_DISTANCE

[number dataDefine]

Default: 0.0

The minimum distance between points within one polygon feature

Random points in polygons

OUTPUT

[vector: point]

Default: [Create temporary layer]

The output random points. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

Advanced parameters

标注

名称

类型

描述

Global minimum distance between points

可选

MIN_DISTANCE_GLOBAL

[number dataDefine]

Default: 0.0

The global minimum distance between points. Should be smaller than the Minimum distance between points (per feature) for that parameter to have an effect.

Maximum number of search attempts (for Min. dist. > 0)

可选

MAX_TRIES_PER_POINT

[number dataDefine]

Default: 10

The maximum number of tries per point. Only relevant if the minimum distance between points is set (and greater than 0).

Random seed

可选

SEED

[数字]

Default: Not set

The seed to use for the random number generator.

Include polygon attributes

INCLUDE_POLYGON_ATTRIBUTES

[boolean]

Default: True

If set, a point will get the attributes from the line on which it is placed.

输出

标注

名称

类型

描述

Random points in polygons

OUTPUT

[vector: point]

The output random points layer.

Number of features with empty or no geometry

FEATURES_WITH_EMPTY_OR_NO_GEOMETRY

[数字]

Total number of points generated

OUTPUT_POINTS

[数字]

Number of missed points

POINTS_MISSED

[数字]

The number of points that could not be generated due to the minimum distance constraint.

Number of features with missed points

POLYGONS_WITH_MISSED_POINTS

[数字]

Not including features with empty or no geometry

Python代码

Algorithm ID: native:randompointsinpolygons

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.13. Random points inside polygons

Creates a new point layer with a given number of random points inside each polygon of the input polygon layer.

Two sampling strategies are available:

  • Points count: number of points for each feature

  • Points density: density of points for each feature

A minimum distance can be specified, to avoid points being too close to each other.

Default menu: Vector ► Research Tools

参数

标注

名称

类型

描述

输入图层

INPUT

[vector: polygon]

Input polygon vector layer

Sampling strategy

STRATEGY

[enumeration]

Default: 0

Sampling strategy to use. One of:

  • 0 --- Points count: number of points for each feature

  • 1 --- Points density: density of points for each feature

Point count or density

VALUE

[number dataDefine]

默认值:1.0

The number or density of points, depending on the chosen Sampling strategy.

Minimum distance between points

MIN_DISTANCE

[数字]

Default: 0.0

The minimum distance between points

Random points

OUTPUT

[vector: point]

Default: [Create temporary layer]

The output random points. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

输出

标注

名称

类型

描述

Random points

OUTPUT

[vector: point]

The output random points layer.

Python代码

Algorithm ID: qgis:randompointsinsidepolygons

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.14. Random points on lines

Creates a point layer with points placed on the lines of another layer.

For each feature (line / multi-line) geometry in the input layer, the given number of points is added to the result layer.

Per feature and global minimum distances can be specified in order to avoid points being too close in the output point layer. If a minimum distance is specified, it may not be possible to generate the specified number of points for each feature. The total number of generated points and missed points are available as output from the algorithm.

The illustration below shows the effect of per feature and global minimum distances and zero/non-zero minimum distances (generated with the same seed, so at least the first point generated will be the same).

../../../../_images/randompointsonlines_mindistance.png

图 27.45 Five points per line feature, left: min. distances = 0, middle: min.distances != 0, right: min. distance != 0, global min. distance = 0

The maximum number of tries per point can be specified. This is only relevant for non-zero minimum distance.

A seed for the random number generator can be provided, making it possible to get identical random number sequences for different runs of the algorithm.

The attributes of the line feature on which a point was generated can be included (Include line attributes).

If you want approximately the same point density for all the line features, you can data-define the number of points using the length of the line feature geometry.

参数

Basic parameters

标注

名称

类型

描述

Input line layer

INPUT

[vector: line]

Input line vector layer

Number of points for each feature

POINTS_NUMBER

[number dataDefine]

Default: 1

Number of points to create

Minimum distance between points (per feature)

可选

MIN_DISTANCE

[number dataDefine]

Default: 0.0

The minimum distance between points within one line feature

Random points on lines

OUTPUT

[vector: point]

Default: [Create temporary layer]

The output random points. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

Advanced parameters

标注

名称

类型

描述

Global minimum distance between points

可选

MIN_DISTANCE_GLOBAL

[number dataDefine]

Default: 0.0

The global minimum distance between points. Should be smaller than the Minimum distance between points (per feature) for that parameter to have an effect.

Maximum number of search attempts (for Min. dist. > 0)

可选

MAX_TRIES_PER_POINT

[number dataDefine]

Default: 10

The maximum number of tries per point. Only relevant if the minimum distance between points is set (and greater than 0).

Random seed

可选

SEED

[数字]

Default: Not set

The seed to use for the random number generator.

Include line attributes

INCLUDE_LINE_ATTRIBUTES

[boolean]

Default: True

If set, a point will get the attributes from the line on which it is placed.

输出

标注

名称

类型

描述

Random points on lines

OUTPUT

[vector: point]

The output random points layer.

Number of features with empty or no geometry

FEATURES_WITH_EMPTY_OR_NO_GEOMETRY

[数字]

Number of features with missed points

LINES_WITH_MISSED_POINTS

[数字]

Not including features with empty or no geometry

Total number of points generated

POINTS_GENERATED

[数字]

Number of missed points

POINTS_MISSED

[数字]

The number of points that could not be generated due to the minimum distance constraint.

Python代码

Algorithm ID: native:randompointsonlines

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.15. Raster pixels to points

Creates a vector layer of points corresponding to each pixel in a raster layer.

Converts a raster layer to a vector layer, by creating point features for each individual pixel's center in the raster layer. Any nodata pixels are skipped in the output.

参数

标注

名称

类型

描述

Raster layer

INPUT_RASTER

[栅格]

Input raster layer

Band number

RASTER_BAND

[raster band]

Raster band to extract data from

Field name

FIELD_NAME

[string]

Default: 'VALUE'

Name of the field to store the raster band value

Vector points

OUTPUT

[vector: point]

Default: [Create temporary layer]

Specify the resulting point layer of pixels centroids. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

输出

标注

名称

类型

描述

Vector points

OUTPUT

[vector: point]

Resulting point layer with pixels centroids

Python代码

Algorithm ID: native:pixelstopoints

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.16. Raster pixels to polygons

Creates a vector layer of polygons corresponding to each pixel in a raster layer.

Converts a raster layer to a vector layer, by creating polygon features for each individual pixel's extent in the raster layer. Any nodata pixels are skipped in the output.

参数

标注

名称

类型

描述

Raster layer

INPUT_RASTER

[栅格]

Input raster layer

Band number

RASTER_BAND

[raster band]

Raster band to extract data from

Field name

FIELD_NAME

[string]

Default: 'VALUE'

Name of the field to store the raster band value

Vector polygons

OUTPUT

[vector: polygon]

Default: [Create temporary layer]

Specify the resulting polygon layer of pixel extents. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

输出

标注

名称

类型

描述

Vector polygons

OUTPUT

[vector: polygon]

Resulting polygon layer of pixel extents

Python代码

Algorithm ID: native:pixelstopolygons

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。

27.1.16.17. Regular points

Creates a new point layer with its points placed in a regular grid within a given extent.

The grid is specified either by the spacing between the points (same spacing for all dimensions) or by the number of points to generate. In the latter case, the spacing will be determined from the extent. In order to generate a full rectangular grid, at least the number of points specified by the user is generated for the latter case.

Random offsets to the point spacing can be applied, resulting in a non-regular point pattern.

Default menu: Vector ► Research Tools

参数

标注

名称

类型

描述

Input extent (xmin, xmax, ymin, ymax)

EXTENT

[范围]

Map extent for the random points

Available methods are:

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

  • Calculate from layout map…: uses extent of a layout map item in the active project

  • Calculate from bookmark…: uses extent of a saved bookmark

  • Use map canvas extent

  • Draw on canvas: click and drag a rectangle delimiting the area to take into account

  • Enter the coordinates as xmin, xmax, ymin, ymax

Point spacing/count

SPACING

[数字]

Default: 100

Spacing between the points, or the number of points, depending on whether Use point spacing is checked or not.

Initial inset from corner (LH side)

INSET

[数字]

Default: 0.0

Offsets the points relative to the upper left corner. The value is used for both the X and Y axis.

Apply random offset to point spacing

RANDOMIZE

[boolean]

Default: False

If checked the points will have a random spacing

Use point spacing

IS_SPACING

[boolean]

Default: True

If unchecked the point spacing is not taken into account

Output layer CRS

CRS

[crs]

Default: Project CRS

CRS of the random points layer

Regular points

OUTPUT

[vector: point]

Default: [Create temporary layer]

Specify the output regular point layer. One of:

  • Create Temporary Layer (TEMPORARY_OUTPUT)

  • 保存到文件…

  • Save to Geopackage…

  • Save to Database Table…

文件编码也可以在此更改。

输出

标注

名称

类型

描述

Regular points

OUTPUT

[vector: point]

The output regular point layer.

Python代码

Algorithm ID: qgis:regularpoints

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

当你在数据处理工具箱某个算法前悬停时,算法 id 将会展现。*参数字*将会提供参数的名称与数值。参考详见`数据处理_控制台`以获取如何从Python控制台中运行数据处理算法。