Hello, A quick question relating to the documentation of the jitter function: http://127.0.0.1:15714/library/base/html/jitter.html jitter(x, factor = 1, amount = NULL) "If amount is NULL (default), we set a <- factor * d/5 where d is the smallest difference between adjacent unique (apart from fuzz) x values." Therefore if length(x) = 1, then d = 0, which means jitter(x) should be equal to x? Which is not the case, i.e.> x <- 1 > jitter(x)[1] 0.9842914 So how does jitter deals with this situation? Does it assume d = x? Thanks IC ________________________________ This message and any attachments contain information that may be RMS Inc. confidential and/or privileged. If you are not the intended recipient (or authorized to receive for the intended recipient), and have received this message in error, any use, disclosure or distribution is strictly prohibited. If you have received this message in error, please notify the sender immediately by replying to the e-mail and permanently deleting the message from your computer and/or storage system. [[alternative HTML version deleted]]
Hello, You can see the code for jitter by typing its name at the prompt. Inline. Em 09-10-2014 18:19, Ingrid Charvet escreveu:> Hello, > > A quick question relating to the documentation of the jitter function: > http://127.0.0.1:15714/library/base/html/jitter.html > > jitter(x, factor = 1, amount = NULL) > > "If amount is NULL (default), we set a <- factor * d/5 where d is the smallest difference between adjacent unique (apart from fuzz) x values." > > Therefore if length(x) = 1, then d = 0, which means jitter(x) should be equal to x? > Which is not the case, i.e. > >> x <- 1 >> jitter(x) > [1] 0.9842914 > > So how does jitter deals with this situation? Does it assume d = x?It doesn't assume, it computes range(x) and acts accordingly. The code lines are z <- diff(r <- range(x[is.finite(x)])) if (z == 0) z <- abs(r[1L]) It has the effect of setting z to x. Try running them. (And with x <- 2 to see the difference.) Hope this helps, Rui Barradas> > Thanks > IC > > ________________________________ > This message and any attachments contain information that may be RMS Inc. confidential and/or privileged. If you are not the intended recipient (or authorized to receive for the intended recipient), and have received this message in error, any use, disclosure or distribution is strictly prohibited. If you have received this message in error, please notify the sender immediately by replying to the e-mail and permanently deleting the message from your computer and/or storage system. > > > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. >
On Oct 9, 2014, at 10:19 AM, Ingrid Charvet wrote:> Hello, > > A quick question relating to the documentation of the jitter function: > http://127.0.0.1:15714/library/base/html/jitter.html > > jitter(x, factor = 1, amount = NULL) > > "If amount is NULL (default), we set a <- factor * d/5 where d is the smallest difference between adjacent unique (apart from fuzz) x values." > > Therefore if length(x) = 1, then d = 0, which means jitter(x) should be equal to x? > Which is not the case, i.e. > >> x <- 1 >> jitter(x) > [1] 0.9842914 > > So how does jitter deals with this situation? Does it assume d = x?The code is right at your fingertips. Just type: jitter -- David.> > [[alternative HTML version deleted]] > > ______________________________________________ > 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.David Winsemius Alameda, CA, USA