How To: Transfer e00 files from one platform to another
How do I suucessfully EXPORT and IMPORT between different platforms?
The following is a list of what you must keep in mind when transferring an export file from one platform to another.
- Run EXPORT with the NONE option. This creates non-compressed ASCII files that are easier to handle than fully or partially compressed ASCII files. Fully or partially compressed ASCII files can cause problems when transferring data across different platforms, such as Sun to PC, or a Sun to an Alpha.
- Always IMPORT the e00 file back into the host platform before transferring, this is to make sure that the e00 file is error free. EXPORT does not check for errors within the coverage, IMPORT does. If changes need to be made to the coverage, they have to be done at the original site, not to the e00 file.
- If transferring data from a workstation to a PC, make sure the exported data is in single precision. Use the ARC COPY command with the SINGLE option to do this. PC ARC/INFO, version 3.4.2d, will accept double precision export files and convert them to single precision for use.
- Use the MAX_LINES option in EXPORT to create more than one volume for the export file. A value of 20 000 will create volumes that are able to fit onto a floppy disk. Use a finite number so that at least two volumes are created. Transfer both files to the other platform and make sure that they are in the same directory when using the IMPORT command. IMPORT automatically searches for the next volume when more than one volume is created.
- CLEAN the coverage with a fuzzy tolerance of 2.0, if it is in real world coordinates, such as UTM or Stateplane. It is advisable to always run CLEAN and BUILD before trying to EXPORT a coverage.
- If any numeric (N-TYPE) items exist, make sure they have one or more decimal places. Use ALTER to change items with 0 decimal places.
- If there is a character (C-TYPE) item, make sure that there is a value in it, do not leave it blank. Place any character, or characters, in any empty records, such as 'x' or 'undefined'.
- If there is a binary (B-TYPE) item, make sure the internal width is 2 or 4.
- If there are any floating (F-TYPE) items, make sure that the internal width is 4 or 8.
- For integer (I-TYPE) items, the maximum width is 16 and the range is +/- 2,147,483,647.
- Make sure that the COVER-ID's are unique in all FAT's, that is if transferring a coverage from a workstation to a PC. The COVER-ID is used for all links to additional user attribute items in PC ARC/INFO, while the COVER# item is used in workstation ArcInfo. CALC the COVER-ID = COVER# in INFO, if the COVER-ID was set to a non-unique set, for the arc and point attribute tables. For the polygon attribute table use CALC COVER-ID = COVER# - 1, as the universe polygon must be 0. Run IDEDIT at the ARC prompt, and then EXPORT.
- If the host cover has .ADD files and/or redefined items, you need to run ADDFIX before importing the coverage to PC ARC/INFO, because the PC does not support redefined items. If this is not done, addressmatching will not work. For Arcview 2.0, there is a patch disk available, with an IMPORT command modified to take care of the problem.
- When transferring from a PC to a UNIX workstation or vice versa, make sure that the ASCII export file is in the proper format. Use dos2unix or unix2dos for Sun, or dosread, doswrite for IBM platforms. If FTP is used this conversion will be done automatically, but it never hurts to make sure. If the e00 file is in DOS format, it will have ^M characters when viewed on a unix platform. PC ARC/INFO, version 3.4.2, provides the unix2dos and dos2unix commands.
- Make sure that any file transfer program used, such as FTP, does so in ASCII format if the NONE option was used. If the PARTIAL or FULL options were used (which is not suggested), set the transfer mode to binary. ie.
'FTP> Mode set to A
'FTP> Mode set to binary
11754 - Copy ArcInfo coverages between machines