The required input for Amelia for Gauss is either the string name of a Gauss dataset or a data matrix. If your data is already in Gauss-format and you want the imputed datasets also to be in that format, all you need to do is specify the string name of the dataset as the only argument for the program.
Alternatively, if your data are in ascii text files, load your data into Gauss and specify the data matrix as the only argument for the program. The easiest way to get ascii data into Gauss is to use the loada procedure that comes with Amelia: For a data set with 5 variables in columns separated by spaces or commas, use dataset=loada("file.txt",5);. Furthermore, the Gauss commands import and importf will read data from a variety of text, spreadsheet, and database formats (which is easier than the external Gauss command, ATOG). Finally, the public domain program DataLoad(see http://gurukul.ucc.american.edu/econ/gaussres/UTILITYS/DATALOAD.HTM) which we use in Amelia for Windows, and commercial program DBMSCopy (see http://www.conceptual.com/) convert back and forth between Gauss-format and the formats of most commercial statistical, data base, and spreadsheet programs.
In addition to Gauss-format (.DAT), the imputed datasets may, if using a Windows operating system, be outputted in ASCII character delimited (.TXT, .CSV, .ASC), ASCII formatted (.PRN), Lotus v1.0 (.WKS), Excel v2.1 (.XLS), Quattro v1.0 (.WQ1), Symphony v1.0 (.WRK), dBase II (.DB2), dBase III (.DBF), Paradox v3.0 (.DB). Setting the global _AMtype changes the output file format. Users running Gauss on other operating systems must output the imputed datasets in Gauss format.