I'm sure there's an easier way, but it's going to be easiest to get a
useful response if we have a reproducible, minimal example, as the
posting guide requests. ?tapply is probably involved.
Stuart Luppescu wrote:
Hello, I have to construct 5 new columns in a data frame depending on
the value of another of the columns in the data frame. The only way I
could figure out to do this was to subset the data frame five times, do
the variable construction, and then rbind the subsets back together.
Here's part of the code I used:
read001 <- read[read$existstr=="001",]
read001$era1end <- NA
read001$era2base <- NA
read001$era2end <- NA
read001$era3base <- read001$era1base
read001$era3end <- read001$era3base + (6 * read001$era3tr)
read011 <- read[read$existstr=="011",]
read011$era1end <- NA
read011$era2base <- read011$era1base
read011$era2end <- read011$era2base + (4 * read011$era2tr)
read011$era3base <- read011$era2end
read011$era3end <- read011$era2end + (6 * read011$era3tr)
...
read2 <- rbind(read001, read011, read100, read110, read111)
Isn't there an easier way to do this?
Thanks.
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