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Message-ID: <4BA21430AE44494AA396994140AF7E0A5AD4ED@mexchange.Mango.local> Date: 2012-11-16T11:04:02Z From: Agnieszka Matoga Subject: Can you have a by variable in Lag function as in SAS An embedded and charset-unspecified text was scrubbed... Name: not available URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20121116/08e1bb86/attachment.pl>