Error: Invalid number of points in arc

Error Message

Issuing the ARCLINES command to draw coverage arcs in ArcPlot displays the following error message:

"Invalid number of points in arc"


One or more arcs in the coverage have more than 499 vertices in the arc. In the coverage data model, an arc can only have 499 vertices per feature.

Solution or Workaround

An arc in a coverage can only have 499 vertices per arc. The 500th vertex is converted to a node, and a new arc is begun at that node.

CLEAN must not be run on a coverage in a Geographic Coordinate System with units of decimal degrees. If the coverage is in geographic coordinates, PROJECT the coverage to a Projected Coordinate System, such as StatePlane or UTM, which uses linear units before performing the following steps.

Make a copy of the coverage before proceeding, in case CLEAN produces unexpected results:

Arc: copy <coverage_name> <copy_name>

  1. Set the FUZZY tolerance for the coverage to a very small value to avoid snapping features that are not coincident. At the Arc: prompt type the following:

    Arc: tolerance <cover_name> fuzzy .001

  2. Run CLEAN for LINE on the coverage to create proper ARC/NODE topology, with the following syntax:

    Arc: clean <cover_name> # # # line