a simple reflection (on the y-axis) of x is -x, but you have to ensure that there are only nonnegative numbers if you want to use the log transformation. So you should reflect on a postive number z greater than abs(min(x)), if min(x)<0. This is done by z-x. Why don't you simply shift your data by this amount z or use a box-cox-transformation at all?
Am Wed, 23 Aug 2006 14:08:08 +0200 schrieb <[EMAIL PROTECTED]>: > Hi, > > This problem may be very easy, but I can't think of how to do it. I > have constructed histograms of various variables in my dataset. Some of > them are negatively skewed, and hence need data transformations > applied. I know that you first need to reflect the negatively skewed > data and then apply another transformation such as log, square root etc > to bring it towards normailty. How is it that I reflect data in R? I'm > sorry if this seems a very simple task, I think it involves going back > to Maths GCSE and relearning reflection, rotation, translation etc! I > have searched the internet, but cannot come up with anything useful on > how to reflect data. > >> hist(Lsoc) #how do I reflect Lsoc in R? > > I am grateful for any help regarding this matter, it is just a very > small part of my analysis and doesn't seem worth agonising hours over. > I will probably kick myself when someone tells me the answer! > > Thank you very much, > > Zoe > > ______________________________________________ > [email protected] 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. > ______________________________________________ [email protected] 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.
