Replacing variables in one dataset with those from another
Hi: Letting d1 and d2 be your two data frames,
merge(d1, d2, by.x = 'x1', by.y = 'num', all.x = TRUE)[, c(2, 4, 3)]
grpnum uniqueid x2 1 D <NA> 276 2 B <NA> 898 3 A GHU82RK02HD7D6 334 4 C GHU82RK02IXPC7 4077 If you want x1 to be the variable name for the new dataset, then dmerge <- merge(d1, d2, by.x = 'x1', by.y = 'num', all.x = TRUE)[, c(2, 4, 3)] names(dmerge)[2] <- 'x1' HTH, Dennis
On Wed, Jun 1, 2011 at 11:30 AM, mcginnis21 <mcginnis at montana.edu> wrote:
Hoping someone out there can help me...this seems like an easy task but I can't figure it out... I want to replace variables in one dataset (Dataset1) with a variable from another dataset (Dataset2). All the values for variables x1 and x2 in Dataset1 have a unique match to the variable uniquenum in Dataset2. ?For example, in Dataset1 grpnum A has a value of 343 for variable x1. ?In Dataset2, 343 will only be found once for variable uniquenum. ?I would like to create a new dataset where the variable x1 from Dataset1 will be replaced by uniqueid from Dataset2. ?So variable x1 for grpnum A now would equal GHU82RK02HD7D6 rather than 343. ? Below is an abbreviated example from my datasets to show what I?m trying to do rather than explain in words because I?m not sure my question is coming across very clearly. ? I have about 100 columns in Dataset1 (x1, x2, etc.) and the variable uniquenum in Dataset2 has about 4,000 values. Dataset1 grpnum ?x1 ? ? ?x2 A ? ? ? 343 ? ? 334 B ? ? ? 313 ? ? 898 C ? ? ? 4076 ? ?4077 D ? ? ? 275 ? ? 276 Dataset2 unique num ? ? ?uniqueid 343 ? ? GHU82RK02HD7D6 4076 ? ?GHU82RK02IXPC7 4077 ? ?GHU82RK02HICZ2 261 ? ? GHU82RK02FLOFU 4100 ? ?GHU82RK02IDO7K 4101 ? ?GHU82RK02HQYQL 4102 ? ?GHU82RK02GADV1 4103 ? ?GHU82RK02G7RQH 4104 ? ?GHU82RK02HQD2E NewDataset grpnum ?x1 ? ? ?x2 a ? ? ? GHU82RK02HD7D6 ? ?Na b ? ? ? Na ? ? ?Na c ? ? ? GHU82RK02IXPC7 ?GHU82RK02HICZ2 d ? ? ? Na ? ? ?Na Thanks for your time and thoughts. ?I hope someone can help! -- View this message in context: http://r.789695.n4.nabble.com/Replacing-variables-in-one-dataset-with-those-from-another-tp3566552p3566552.html Sent from the R help mailing list archive at Nabble.com.
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