function for inverse normal transformation
I have a continuous data. So to calculate the inverse normal transformation, I thought that I should first calculate the Z-score normalized data and then, calculate the p-value et the quantile transformation. Does this seem to be more sensible my_data.p =2*pnorm(abs(scale(my_data)),lower.tail=FALSE) my_data.q= qnorm(my_data.p) The attached file shows the histogram of a small data set before transformation, the p-value generated from the Z-score normalized data and then, the qnorm-transformed data. Thanks for your feedback,
From: Duncan Murdoch <murdoch.duncan at gmail.com>
To: carol white <wht_crl at yahoo.com>
Cc: "r-help at stat.math.ethz.ch" <r-help at stat.math.ethz.ch>
Sent: Friday, July 20, 2012 1:42 PM
Subject: Re: [R] function for inverse normal transformation
To: carol white <wht_crl at yahoo.com>
Cc: "r-help at stat.math.ethz.ch" <r-help at stat.math.ethz.ch>
Sent: Friday, July 20, 2012 1:42 PM
Subject: Re: [R] function for inverse normal transformation
On 12-07-20 7:36 AM, carol white wrote: > Thanks for your reply. > > So to derive it from a given data set, is the following correct to do? > > my_data.p =2*pnorm(abs(my_data),lower.tail=FALSE) > > my_data.q = qnorm(my_data.p) I don't know what you're trying to do, but that doesn't look like it does something sensible.? It would take a value like 2, compute the p to be 0.045, and return the corresponding quantile of the normal distribution, i.e. -1.69 or so.? I don't know why you'd want to do that. Duncan Murdoch > > Cheers, > > > ________________________________ >? From: Duncan Murdoch <murdoch.duncan at gmail.com> > To: carol white <wht_crl at yahoo.com> > Cc: "r-help at stat.math.ethz.ch" <r-help at stat.math.ethz.ch> > Sent: Friday, July 20, 2012 1:23 PM > Subject: Re: [R] function for inverse normal transformation > > On 12-07-20 6:21 AM, carol white wrote: >> Hi, >> What is the function for inverse normal transformation? > > qnorm > > Duncan Murdoch > >> Thanks, >> >> Carol >> >>? ? ? [[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. >> -------------- next part -------------- A non-text attachment was scrubbed... Name: tmp.png Type: image/png Size: 16620 bytes Desc: not available URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20120720/d5ed78bd/attachment.png>