Problem: All the Coverage to Grid tools fail when using a Lookup table (LUT)


The Point Coverage to Grid, Line Coverage to Grid, or Polygon Coverage to Grid tools fail when using an item from a Lookup table (LUT). The execution error message will contain one or more of the following:

1. LUT is character in one file and numeric in the other.
2. Cannot access input grid codes.
3. Unable to grid coverage.
4. Bailing out of POLYGRID.


The item, in both the feature attribute table (FAT) and the LUT, must be numeric. This tool requires that the Value Item be numeric in the LUT to match the chosen FAT's numeric Value Item.

Solution or Workaround

Ensure the LUT item is numeric by checking its type on the LUT property page (Item tab in ArcCatalog).

If the item is not numeric, then you can perform either of the following:

  • Create a new, numeric item and copy the values into it.

    A. Open ArcMap.
    B. Add the Table.
    C. Right-click the table name.
    D. Click Open.
    E. Click Options.
    F. Click Add Field.
    G. Add a numeric field to the table. Make sure the data type, input width, display width, and name(s) match the FAT's column attributes.
    H. Click OK.
    I. Right-click the numeric field that was added in step E.
    J. Click Calculate Values to bring up the Field Calculator dialog.
    K. Type CINT([Char_field]) in the expression box. Char_field is the character field you wish to convert to integers.

    [O-Image] Transfer char field to a numeric field using the Field Calculator
  • Alter the original items data type to numeric.

    1. Start ArcCatalog.
    2. Right-click the table and select Properties.
    3. Go to the Items tab.
    4. Select the field whose properties you wish to change.
    5. Click Edit button.
    6. Click on the Item type and choose a different type from the dropdown list.

    [O-Image] Change a field from one type to another