Problem: Large GRIDPOINT values are rounded


GRIDPOINT may round large numbers. For example, a value of 18,000,001 in a grid may become 18,000,000 in a coverage.

This document shows how to reapply the values before they were rounded from an integer grid.


This is a known issue with GRIDPOINT.

Solution or Workaround

  1. Add small unique identifier values to each record of the grid's VAT. For example, you can use the $RECNO (record number) of the VAT.

    Tables: ADDITEM mygrid.vat newval 6 6 i
    Tables: SELECT mygrid.vat
    Tables: CALCULATE newval = $recno

  2. Convert the grid to a coverage based on this new value item.

    Arc: GRIDPOINT mygrid mypoint newval

  3. Join the original VAT to the new PAT using the unique value item as the relate_item between them.

    Arc: JOINITEM mypoint.pat mygrid.vat mypoint.pat newval