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Subscripting problem with is.na()

Dear Georg,

You need to learn a bit more about the subsetting methods, depending on 
the object structure you're trying to subset.

More specifically, when you run this: ds_test[is.na(ds_test$var1)]
you get this error: "Error in `[.data.frame`(ds_test, 
is.na(ds_test$var1)) : undefined columns selected"

This means that R does not understand which column you're trying to 
select. But you're actually trying to select rows.

Using a single bracket '[' on a data.frame does the same as for 
matrices: you need to specify rows and columns, like this:
ds_test[is.na(ds_test$var1), ] ## notice the last comma
ds_test[is.na(ds_test$var1), ] <- 0 ## works on all columns because you 
didn't specify any after the comma

If you want it only for "var1", then you need to specify the column:
ds_test[is.na(ds_test$var1), "var1"] <- 0

It's the same problem with your 2nd and 4th tries (4th one has other 
problems). Your 3rd try does not change ds_test at all.

HTH,
Ivan

--
Ivan Calandra, PhD
Scientific Mediator
University of Reims Champagne-Ardenne
GEGENAA - EA 3795
CREA - 2 esplanade Roland Garros
51100 Reims, France
+33(0)3 26 77 36 89
ivan.calandra at univ-reims.fr
--
https://www.researchgate.net/profile/Ivan_Calandra
https://publons.com/author/705639/

Le 23/06/2016 ? 15:57, G.Maubach at weinwolf.de a ?crit :