I'm getting some unexpected behavior with the stack() command. The attached spreadsheet has data structured as in the "by variable" example on p. 23 of the user's guide. I followed the sample script as on p. 24, except I opened the file as .xlsx and do the stacking from v2..v13 since v1 is the country names. When I open the spreadsheet, the "variables" v2, v3, etc have the correct column information, but the resulting variables x1 and x2 aren't correct. For example, x1 becomes integer-valued. I can't figure out what I'm doing wrong here; suggestions welcome!