[Gretl-users] changes to "join" command in CVS and snapshots

Hello all, A heads-up for those using gretl's "join" command: there are some changes in current CVS and the snapshots for Windows and Mac. Most of the changes represent substantial enhancements. In particular we now support a much more flexible filter; see the updated chapter on join in the current Gretl User's Guide for details. But please note a couple of backward-incompatible points: 1) We now check the column headings in the CSV file from which data are to be drawn, and if they're not valid gretl identifiers (e.g. they contain spaces) we "fix" them. In the context of the join command you must use the fixed names. The fix-up rule is quite simple and is set out in the help for the new fixname() function, which you can use if you're in doubt as to what will happen to a given column name under the new policy. Example: eval fixname("1. Some name") gives the result "Some_name". 2) If you want to use a string constant in a join filter you must enclose it in backslash-escaped double quotes. For example, suppose the CSV file contains a string-valued column named "gender" with values "F" and "M" and you want to filter on gender = "F". Your filter option must then look like this --filter="gender==\"F\"" Alternatively you can define a string variable and use it in place of the string constant. So after doing string wanted = "F" you could use --filter="gender==wanted" and get the same result. Allin Cottrell