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Handling large numbers of farms in NAADSM
NAADSM 3.1
I have a large number of farms for the population that I would like to include in my NAADSM model: I currently have about 85,000 farms, and want to add about 4,000 more. I realize that this is a large data set so I wasn't sure if NAADSM would handle it. I imported my population one province at a time. After I had entered the last province I got the message: "Too many units. There are too many units (zyx) to display practically in this program. You may use Microsoft Access or a similar application to edit units in your scenario database." I also get this message when I go to "Set Up units". Can I enter the remaining data into Access directly? | ||
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Re: Handling large numbers of farms in NAADSM
NAADSM/PC will run models that contain many units, but it is limited in the number of units that can be displayed in the "Set up starting units" window: the application can display only about 65,000 units in the "Set up starting units" window. (This limit, not entirely coincidentally, is also the maximum number of rows that users can have in older versions of Microsoft Excel.)
If you wish to include or edit more units than this in your NAADSM scenario file, you will need to edit the scenario file directly in Microsoft Access. Every NAADSM scenario file is a relational database that is compatible with and can be opened directly in Microsoft Access.
To edit your units in Access, view the table named dynHerd. In this table you will find all of the same columns that the herd list editor in NAADSM offers. As long as your data is in the proper format, you should be able to import additional units into Access from whatever data source you choose to use (Excel spreadsheets, plain text, or any of a number of other applications). the NAADSM User's Guide documents the database tables, and should provide enough information that you can format your data correctly.
Once your units are in the scenario database file, you can open the file with NAADSM as usual, and the map will display all of them. (Note, though, that the map display becomes less useful if there are a lot of units, as they are too close together to clearly distinguish from one another.)
Good luck, and let us know if you have any problems!
Re: Handling large numbers of farms in NAADSM
I tested the import and append of a large number of units and can not replicate this error in verion 3.1.26 or 3.1.28. The dialog box did not correctly show the total number of units when the count exceeds 65,535 (it simply showed "zyx"), but that has been fixed and the dialog will show the correct total count in future releases. In my tests I imported over 70,000 herds and was able to proceed to the next parameter form without the application freezing. After import, adding the data to the database does take several seconds (on my PC about 10 seconds). As Aaron indicated, the units will be imported, but having more than 65,535 will prevent you from editing the herd list in NAADSM. If you wish to have me test an import using your data please contact me at: ric.hupalo@colostate.edu