Yesterday I needed to export data from Excel 2010 (or 2007) to WEKA datamining software, and found out that Excel's CSV export is pretty much broken. Hey, MS developers, ever heard about the first word of CSV acronym? Yes, it's COMMA, not SEMICOLON.

Also, WEKA does want strings enclosed in "'s, and on my czech locale, Excel exports decimal numbers with comma instead of dot (that's probably the source of semicolon messup).

Therefore, I wrote the addin that exports active selection as a proper CSV, or WEKA's preferred ARFF format (numeric and discrete attributes are supported by simple key: first row is headers, if all other rows are numbers, it's numeric, otherwise it is a set of discrete values).

You can easily add support for another file formats by inheriting from ITextFileFormat, adding instance of it to list in exportButton_Click, and recompiling.

• Source
• Installer (for Excel 2007 & 2010)

^{*) Works on my PC, no further guarrantees :)
**) If you modify/improve it, drop me a note, and I'll be happy to re-release with your changes}