Re: [R] Normalization and missing values

2005-04-14 Thread Jonathan Baron
On 04/13/05 21:05, Chris Bergstresser wrote: This article is great; thanks for providing it. The authors recommend either using "ML Estimation" or "Multiple Imputation" to fill in the missing data. They don't talk much about which is better for certain situations, however. Multiple imput

Re: [R] Normalization and missing values

2005-04-14 Thread Adaikalavan Ramasamy
What the best missing value imputation ? It depends on how the values were generated (e.g. missing at random, informative missing ) and what type of data (e.g. counts, continuous). If you are interested in this you could either : 1) take the dataset of complete cases and impute missing values acc

Re: [R] Normalization and missing values

2005-04-13 Thread Chris Bergstresser
I'd just like to thank everyone who wrote in in response to my questions -- it's been greatly helpful, and appreciated. Jonathan Baron wrote: On 04/13/05 11:36, Chris Bergstresser wrote: First, I didn't see a function in R which does normalization -- did I miss it? What's the best way t

RE: [R] Normalization and missing values

2005-04-13 Thread Ted Harding
On 13-Apr-05 Berton Gunter wrote: > You can't expect statistical procedures to rescue you from > poor data. But they can "kiss it better". (:-x) Ted. E-Mail: (Ted Harding) <[EMAIL PROTECTED]> Fax-to-email: +44 (0)870 094 086

Re: [R] Normalization and missing values

2005-04-13 Thread WeiWei Shi
the way of scaling, IMHO, really depends on the distribution of each column in your original files. if each column in your data follows a normal distrbution, then a standard "normalization" will fit your requirement. My previous research in microarray data shows me a simple "linear standardization

Re: [R] Normalization and missing values

2005-04-13 Thread Achim Zeileis
On Wed, 13 Apr 2005 14:33:25 -0300 (ADT) Rolf Turner wrote: > > Bert Gunter wrote: > > > You can't expect statistical procedures to rescue you from poor > > data. > > That should ***definitely*** go into the fortune package > data base!!! :-) added for the next release. Z >

Re: [R] Normalization and missing values

2005-04-13 Thread Wensui Liu
before I know the scale() function, I just do it by coding it myself. But probably you could find some cool stuffs in dprep library. I've never tried it anyway. for missing values, it is way more complex and also depends on the methodology you are going to use. some methods are more tolerant to mi

Re: [R] Normalization and missing values

2005-04-13 Thread Jonathan Baron
On 04/13/05 11:36, Chris Bergstresser wrote: Hi all -- I've got a large dataset which consists of a bunch of different scales, and I'm preparing to perform a cluster analysis. I need to normalize the data so I can calculate the difference matrix. First, I didn't see a function in R

RE: [R] Normalization and missing values

2005-04-13 Thread Rolf Turner
Bert Gunter wrote: > You can't expect statistical procedures to rescue you from poor > data. That should ***definitely*** go into the fortune package data base!!! cheers, Rolf Turner

RE: [R] Normalization and missing values

2005-04-13 Thread Berton Gunter
Bergstresser > Sent: Wednesday, April 13, 2005 9:37 AM > To: r-help@stat.math.ethz.ch > Subject: [R] Normalization and missing values > > Hi all -- > > I've got a large dataset which consists of a bunch of different > scales, and I'm preparing to perfo

[R] Normalization and missing values

2005-04-13 Thread Chris Bergstresser
Hi all -- I've got a large dataset which consists of a bunch of different scales, and I'm preparing to perform a cluster analysis. I need to normalize the data so I can calculate the difference matrix. First, I didn't see a function in R which does normalization -- did I miss it? What's