QGIS algorithm - v.extract

QGIS Algorithm provided by GRASS v.extract (grass:v.extract). Selects vector objects from a vector layer and creates a new layer containing only the selected objects.

grass_v_extract(
  input = qgisprocess:::qgis_default_value(),
  where = qgisprocess:::qgis_default_value(),
  type = qgisprocess:::qgis_default_value(),
  file = qgisprocess:::qgis_default_value(),
  random = qgisprocess:::qgis_default_value(),
  new = qgisprocess:::qgis_default_value(),
  .d = qgisprocess:::qgis_default_value(),
  .t = qgisprocess:::qgis_default_value(),
  .r = qgisprocess:::qgis_default_value(),
  output = qgisprocess:::qgis_default_value(),
  GRASS_REGION_PARAMETER = qgisprocess:::qgis_default_value(),
  GRASS_SNAP_TOLERANCE_PARAMETER = qgisprocess:::qgis_default_value(),
  GRASS_MIN_AREA_PARAMETER = qgisprocess:::qgis_default_value(),
  GRASS_OUTPUT_TYPE_PARAMETER = qgisprocess:::qgis_default_value(),
  GRASS_VECTOR_DSCO = qgisprocess:::qgis_default_value(),
  GRASS_VECTOR_LCO = qgisprocess:::qgis_default_value(),
  GRASS_VECTOR_EXPORT_NOCAT = qgisprocess:::qgis_default_value(),
  ...,
  .complete_output = .complete_output_option(),
  .quiet = .quiet_option(),
  .messages = .message_option()
)

Arguments

input

source - Vector layer. Path to a vector layer.

where

string - WHERE conditions of SQL statement without 'where' keyword. String value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

type

enum of ("point", "line", "boundary", "centroid", "area", "face") - Input feature type. Number of selected option, e.g. '1'. Comma separated list of options, e.g. '1,3'.

file

file - Input text file with category numbers/number ranges to be extracted. Path to a file.

random

number - Number of random categories matching vector objects to extract. A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

new

number - Desired new category value (enter -1 to keep original categories). A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

.d

boolean - Dissolve common boundaries. 1 for true/yes. 0 for false/no. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression. Original algorithm parameter name: -d.

.t

boolean - Do not copy attributes. 1 for true/yes. 0 for false/no. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression. Original algorithm parameter name: -t.

.r

boolean - Reverse selection. 1 for true/yes. 0 for false/no. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression. Original algorithm parameter name: -r.

output

vectorDestination - Selected. Path for new vector layer.

GRASS_REGION_PARAMETER

extent - GRASS GIS region extent. A comma delimited string of x min, x max, y min, y max. E.g. '4,10,101,105'. Path to a layer. The extent of the layer is used..

GRASS_SNAP_TOLERANCE_PARAMETER

number - v.in.ogr snap tolerance (-1 = no snap). A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

GRASS_MIN_AREA_PARAMETER

number - v.in.ogr min area. A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

GRASS_OUTPUT_TYPE_PARAMETER

enum of ("auto", "point", "line", "area") - v.out.ogr output type. Number of selected option, e.g. '1'. Comma separated list of options, e.g. '1,3'.

GRASS_VECTOR_DSCO

string - v.out.ogr output data source options (dsco). String value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

GRASS_VECTOR_LCO

string - v.out.ogr output layer options (lco). String value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

GRASS_VECTOR_EXPORT_NOCAT

boolean - Also export features without category (not labeled). Otherwise only features with category are exported. 1 for true/yes. 0 for false/no. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

...

further parameters passed to qgisprocess::qgis_run_algorithm()

.complete_output

logical specifying if complete out of qgisprocess::qgis_run_algorithm() should be used (TRUE) or first output (most likely the main) should read (FALSE). Default value is TRUE.

.quiet

logical specifying if parameter .quiet for qgisprocess::qgis_run_algorithm() Default value is TRUE.

.messages

logical specifying if messages from qgisprocess::qgis_run_algorithm() should be printed (TRUE) or not (FALSE). Default value is FALSE.

Details

Outputs description

• output - outputVector - Selected