Buffer (Coverage)

This tool only works with an ArcInfo license and will only be available in ArcToolbox if you have installed ArcInfo Workstation.

Creates buffer polygons around specified input coverage features.

Learn more about how Buffer works


Buffer illustration

Usage tips


Buffer_arc (in_cover, out_cover, feature_type, buffer_item, buffer_table, buffer_distance, fuzzy_tolerance, buffer_shape, buffer_side)
Parameter Explanation Datatype
Input Coverage (Required)

The coverage containing features to be buffered.

Output Coverage (Required)

The polygon buffer coverage to be created.

Feature Type (Optional)

The feature class to be buffered:

  • LINE—Arcs will be buffered. This is the default option.
  • POLY—Polygons will be buffered.
  • POINT—Points will be buffered.
  • NODE—Nodes will be buffered.

Buffer Item (Optional)

An item in the feature attribute table of input coverage whose value is used as the feature's buffer distance. If a buffer table is used, the buffer item functions as a lookup item in the buffer table.

Buffer Table (Optional)

An INFO lookup table that lists a buffer distance for each buffer item. A buffer table can be specified only if the buffer item is specified. The buffer table contains at least two items:

  • Buffer Item—Defined the same as buffer item in the input coverage feature attribute table. The buffer table must be sorted on this item in ascending order.
  • DIST—The buffer distance for each buffer item value. DIST must be defined as a numeric item (that is, N, I, F, or B). A lookup table will categorize item values.

ArcInfo Table
Buffer Distance (Optional)

The distance used to create buffer zones around input coverage features when buffer item and buffer table are not specified. The default buffer distance is 0.125 coverage units. This default buffer distance will be applied whenever a value for this parameter is not specified. The smallest buffer distance that can be computed is 0.00000005 coverage units. Specifying a buffer distance below this threshold will result in an empty output coverage. For polygon features, if a negative buffer distance is used, buffers will be generated on the insides of polygons.

Fuzzy Tolerance (Optional)

The minimum distance between coordinates in the output coverage. By default, the minimum fuzzy tolerance value from the input coverage and erase coverage is used. Learn more about how the Default Fuzzy Tolerance is Calculated

Buffer Shape (Optional)

For lines, the shape of the buffer at the line endpoints.

  • ROUND—Will make an end in the shape of a halfcircle.
  • FLAT—Will construct rectangular line endings with the middle of the short side of the rectangle coincident with the endpoint of the line.

Buffer Side (Optional)

For lines, the topological side on which the buffer may be generated.

  • FULL—On all sides. This is the default.
  • LEFT—"Half buffer" on the topological left side of a line.
  • RIGHT—"Half buffer" on the topological right side of a line.

Data types for geoprocessing tool parameters

Script Example

import arcgisscripting
gp = arcgisscripting.create()

gp.workspace = "c:/base_data"
gp.toolbox = "arc"
gp.buffer_arc("road", "roadbuf", "line", "#", "#", "200", "0.5",  "round", "full")

See Also

  • Buffer (Analysis)
  • Dissolve (Coverage)
  • Eliminate (Data Management)
  • Eliminate (Coverage)