On 26.02.2011 15:43, Frank Harrell wrote:
Yao,
I wonder how likely it is that log transformations fit the data. More often
I find that the flexibility of restricted cubic splines is needed.
One of the things that people take for granted when using log() is that they
are assuming that k=0 in making the transformation log(x + k). It is often
the case the the proper origin is not zero. This also impacts the problem
you encountered.
Besides all that, you can specify limits to predictors to nomogram() in a
variety of ways as listed in the help file. Try that.
Frank
-----
Frank Harrell
Department of Biostatistics, Vanderbilt University
Frank,
looks like you are also using this Nabble interface now:
1. You have written to the R-help mailing list only rather than to
"Yao". Please answer also directly: not all posters are on the mailing list.
2. Please quote the original question, otherwise readers of the list
cannot remember and do not learn too much without having the context
apparent.
Best,
Uwe
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