QGIS algorithm - v.generalize

QGIS Algorithm provided by GRASS v.generalize (grass:v.generalize). Vector based generalization.

grass_v_generalize(
  input = qgisprocess:::qgis_default_value(),
  type = qgisprocess:::qgis_default_value(),
  cats = qgisprocess:::qgis_default_value(),
  where = qgisprocess:::qgis_default_value(),
  method = qgisprocess:::qgis_default_value(),
  threshold = qgisprocess:::qgis_default_value(),
  look_ahead = qgisprocess:::qgis_default_value(),
  reduction = qgisprocess:::qgis_default_value(),
  slide = qgisprocess:::qgis_default_value(),
  angle_thresh = qgisprocess:::qgis_default_value(),
  degree_thresh = qgisprocess:::qgis_default_value(),
  closeness_thresh = qgisprocess:::qgis_default_value(),
  betweeness_thresh = qgisprocess:::qgis_default_value(),
  alpha = qgisprocess:::qgis_default_value(),
  beta = qgisprocess:::qgis_default_value(),
  iterations = qgisprocess:::qgis_default_value(),
  .t = qgisprocess:::qgis_default_value(),
  .l = qgisprocess:::qgis_default_value(),
  output = qgisprocess:::qgis_default_value(),
  error = 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 - Input layer. Path to a vector layer.

type

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

cats

string - Category values. 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.

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.

method

enum of ("douglas", "douglas_reduction", "lang", "reduction", "reumann", "boyle", "sliding_averaging", "distance_weighting", "chaiken", "hermite", "snakes", "network", "displacement") - Generalization algorithm. Number of selected option, e.g. '1'. Comma separated list of options, e.g. '1,3'.

threshold

number - Maximal tolerance value. 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.

look_ahead

number - Look-ahead parameter. 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.

reduction

number - Percentage of the points in the output of 'douglas_reduction' algorithm. 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.

slide

number - Slide of computed point toward the original point. 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.

angle_thresh

number - Minimum angle between two consecutive segments in Hermite method. 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.

degree_thresh

number - Degree threshold in network generalization. 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.

closeness_thresh

number - Closeness threshold in network generalization. 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.

betweeness_thresh

number - Betweenness threshold in network generalization. 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.

alpha

number - Snakes alpha parameter. 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.

beta

number - Snakes beta parameter. 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.

iterations

number - Number of iterations. 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.

.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.

.l

boolean - Disable loop support. 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: -l.

output

vectorDestination - Generalized. Path for new vector layer.

error

vectorDestination - Errors. 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

• error - outputVector - Errors

• output - outputVector - Generalized