[R] tansformation of variables in cph from rms package

[Frank Harrell]

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

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Frank Harrell
Department of Biostatistics, Vanderbilt University
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