Converting factors to bounded random numerical data
This should work:
a <- data.frame(X=rnorm(25, 20, 4), Y=rnorm(25, 15, 3),
Z=sample(c(LETTERS[1:3]), 25, replace=TRUE))
head(a)
X Y Z 1 17.77449 14.425221 B 2 19.95400 13.408439 A 3 13.40162 12.219984 A 4 15.89822 19.214026 B 5 18.55717 14.568691 B 6 19.86619 11.606099 B
Zfact <- data.frame(factor=LETTERS[1:3], low=c(1, 5, 10), high=c(4, 9,
12))
Zfact
factor low high 1 A 1 4 2 B 5 9 3 C 10 12
set.seed(42) a$Zval <- runif(nrow(a), Zfact$low[as.numeric(a$Z)],
Zfact$high[as.numeric(a$Z)])
head(a, 10)
X Y Z Zval 1 17.77449 14.42522 B 8.659224 2 19.95400 13.40844 A 3.811226 3 13.40162 12.21998 A 1.858419 4 15.89822 19.21403 B 8.321791 5 18.55717 14.56869 B 7.566982 6 19.86619 11.60610 B 7.076384 7 14.72275 18.38715 A 3.209765 8 26.09711 17.79988 C 10.269333 9 18.72558 15.64477 C 11.313985 10 17.33280 19.03034 B 7.820259 ---------------------------------------------- David L Carlson Associate Professor of Anthropology Texas A&M University College Station, TX 77843-4352
-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
project.org] On Behalf Of jim holtman
Sent: Wednesday, October 10, 2012 8:32 PM
To: KoopaTrooper
Cc: r-help at r-project.org
Subject: Re: [R] Converting factors to bounded random numerical data
You need to include how many random numbers you want to create; you
are asking for only 1, that is why they are are the same. You
probably want something like:
a$Z<-ifelse(a$Z=="L"
,sample(1:4, nrow(a), TRUE)
,ifelse(a$Z=="M"
,sample(5:9, nrow(a), TRUE)
,ifelse(a$Z=="U"
,sample(10:12, nrow(a), TRUE)
, -42 # you had a character which would have converted
everything to character
)
)
)
On Wed, Oct 10, 2012 at 8:36 PM, KoopaTrooper <ncooper1 at tulane.edu>
wrote:
I have a data set (a) with three columns (X,Y,Z). The first 2 columns
are
numeric. The third (Z) is a factor with three levels A,B,C. I want to
turn
each A into a different random number between 1 and 4, each B into a different random number between 5 and 8, etc. I tried this: a$Z<-
ifelse(a$Z=="L",sample(1:4,1),ifelse(a$Z=="M",sample(5:9,1),ifelse(a$Z= ="U",sample(10:12,1),"")
and it almost worked but changed all the "A's" into the same random
number.
I need a different random number for each A. Ideas? Thanks, -- View this message in context:
http://r.789695.n4.nabble.com/Converting-factors-to-bounded-random- numerical-data-tp4645801.html
Sent from the R help mailing list archive at Nabble.com.
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and provide commented, minimal, self-contained, reproducible code.
-- Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it.
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting- guide.html and provide commented, minimal, self-contained, reproducible code.