> -----Original Message----- > From: Jonathan Williams > [mailto:[EMAIL PROTECTED] > Sent: 15 March 2004 12:48 > To: Ethz. Ch > Subject: [R] imputation of sub-threshold values > > > Security Warning: > If you are not sure an attachment is safe to open contact > Andy on x234. > There are 0 attachments with this message. > ________________________________________________________________ > > Is there a good way in R to impute values which exist, > but are less than the detection level for an assay? > Thanks, >
There's no failsafe way to do this in ANY language. Imputing using the value of the detection level, or half way between there and zero (for strictly positive parameters) are two methods commonly used in the pharma industry, if the proportion of results below detection level is small. Simon Fear Senior Statistician Syne qua non Ltd Tel: +44 (0) 1379 644449 Fax: +44 (0) 1379 644445 email: [EMAIL PROTECTED] web: http://www.synequanon.com Number of attachments included with this message: 0 This message (and any associated files) is confidential and\...{{dropped}} ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
