library(rms) #RCS
载入需要的程辑包：Hmisc
载入需要的程辑包：lattice
载入需要的程辑包：Formula
载入程辑包：‘Hmisc’
The following objects are masked from ‘package:base’:
format.pval, units
载入需要的程辑包：SparseM
载入程辑包：‘SparseM’
The following object is masked from ‘package:base’:
backsolve
Warning messages:
1: In .recacheSubclasses(def@className, def, env) :
undefined subclass "packedMatrix" of class "replValueSp"; definition not updated
2: In .recacheSubclasses(def@className, def, env) :
undefined subclass "packedMatrix" of class "mMatrix"; definition not updated