43 lines
1.4 KiB
Plaintext
43 lines
1.4 KiB
Plaintext
|
|
||
|
|
R Under development (unstable) (2020-12-17 r79644) -- "Unsuffered Consequences"
|
||
|
|
Copyright (C) 2020 The R Foundation for Statistical Computing
|
||
|
|
Platform: x86_64-pc-linux-gnu (64-bit)
|
||
|
|
|
||
|
|
R is free software and comes with ABSOLUTELY NO WARRANTY.
|
||
|
|
You are welcome to redistribute it under certain conditions.
|
||
|
|
Type 'license()' or 'licence()' for distribution details.
|
||
|
|
|
||
|
|
R is a collaborative project with many contributors.
|
||
|
|
Type 'contributors()' for more information and
|
||
|
|
'citation()' on how to cite R or R packages in publications.
|
||
|
|
|
||
|
|
Type 'demo()' for some demos, 'help()' for on-line help, or
|
||
|
|
'help.start()' for an HTML browser interface to help.
|
||
|
|
Type 'q()' to quit R.
|
||
|
|
|
||
|
|
> library(survival)
|
||
|
|
> library(splines)
|
||
|
|
>
|
||
|
|
> # the nsk function should give the same solution as ns, but with a different
|
||
|
|
> # parameterization
|
||
|
|
> #
|
||
|
|
> xx <- runif(500, 1, 100)
|
||
|
|
> yy <- 10*log(xx) + rnorm(500, 0, 2)
|
||
|
|
> tdata <- data.frame(xx=xx, yy=yy)
|
||
|
|
> fit1 <- lm(yy ~ ns(xx, df=4), tdata, model=TRUE)
|
||
|
|
> fit2 <- lm(yy ~ nsk(xx, df=4, b=0), tdata)
|
||
|
|
> all.equal(predict(fit1), predict(fit2)) # same solution
|
||
|
|
[1] TRUE
|
||
|
|
>
|
||
|
|
> xattr <- attributes(fit1$model[[2]])
|
||
|
|
> allknots <- sort(c(xattr$knots, xattr$Boundary.knots)) # knots that were used
|
||
|
|
> pred.knot <- predict(fit1, newdata=list(xx=allknots))
|
||
|
|
> all.equal(pred.knot[-1] - pred.knot[1], coef(fit2)[-1],
|
||
|
|
+ check.attributes = FALSE)
|
||
|
|
[1] TRUE
|
||
|
|
>
|
||
|
|
>
|
||
|
|
> proc.time()
|
||
|
|
user system elapsed
|
||
|
|
0.857 0.036 0.887
|