Hi, I'm analysing dose-response data of several treatments using the DRC package. My observation is that the results for every single treatment changes if there are other treatments contained in the same data frame. My understanding (mis-?) is that the function drm() provides for this case: 'drm(formula, curveid, pmodels, weights, data = NULL, ... Arguments: (...) curveid - a numeric vector or factor containing the grouping of the data.' Is it correct use to provide drm() with a data.frame containing doses, responses and several treatments or is the only way to split everything up into one data frame per treatment? Cheers, Hendrik ______________________________________________________________________ The information in this email is confidential and intend...{{dropped:4}}

Hi Hendrik, I recall using DRC some time ago and being pleased with it, however I also recall it being a CRAN package (not bioc). Have you tried contacting the package author via their webpage ( http://www.bioassay.dk/ ) ? Not to say this is exclusive with people who may have used the package on bioc-list, but the authors are perhaps the best source for information about how their functions were intended to be used. Best, --t On Mon, Feb 25, 2013 at 8:39 PM, Hendrik Falk <falk@wehi.edu.au> wrote: > Hi, > > I'm analysing dose-response data of several treatments using the DRC > package. My > observation is that the results for every single treatment changes if > there are > other treatments contained in the same data frame. > > My understanding (mis-?) is that the function drm() provides for this case: > 'drm(formula, curveid, pmodels, weights, data = NULL, ... > > Arguments: > (...) > curveid - a numeric vector or factor containing the grouping of the data.' > > Is it correct use to provide drm() with a data.frame containing doses, > responses and > several treatments or is the only way to split everything up into one data > frame per > treatment? > > Cheers, > Hendrik > > > > ______________________________________________________________________ > The information in this email is confidential and inte...{{dropped:21}}