Displaying 2 results from an estimated 2 matches for "gbsg".
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gbs
2012 Jan 09
2
Joint confidence interval for fractional polynomial terms
Dear R users,
The package 'mfp' that fits fractional polynomial terms to predictors.
Example:
data(GBSG)
f <- mfp(Surv(rfst, cens) ~ fp(age, df = 4, select = 0.05)
+ fp(prm, df = 4, select = 0.05), family = cox, data = GBSG)
print(f)
To describe the association between the original predictor, eg. age and
risk for different values of age I can plot it the polynomials and fitted
co...
2005 Sep 02
1
C-index : typical values
...tting values less than 0.5
on real datasets. Can someone tell me where I am going wrong please ?
Here is an example using the German Breast Study Group data available in
the mfp package. The predictors in the model were selected by stepAIC().
library(Design); library(Hmisc); library(mfp); data(GBSG)
fit <- cph( Surv( rfst, cens ) ~ htreat + tumsize + tumgrad +
posnodal + prm, data=GBSG, x=T, y=T )
val <- validate.cph( fit, dxy=T, B=200 )
round(val, 3)
index.orig training test optimism index.corrected n
Dxy -0.377 -0.383 -0.3...