# [R] generating points over a function, its possible???

Peter Dalgaard BSA p.dalgaard at biostat.ku.dk
Fri Jun 21 23:04:03 CEST 2002

```kjetil halvorsen <kjetilh at umsanet.edu.bo> writes:

> what you need is rnorm, which gives N(0,1) variates, and then multiply
> with the standard deviation you have estimated, sqrt(13.01403). Then
>
> x (your data ve ctor)
> yhat <- 9.7909 + 0.035*x
> ysim <- yhat + sqrt(13.01403)*rnorm(x)

Or, using the fact that rnorm has further arguments:

ysim <- rnorm(length(x), mean=9.7909+0.035*x, sd=sqrt(13.01403))

(Yes, you can use x instead of length(x), but once bitten...)

--
O__  ---- Peter Dalgaard             Blegdamsvej 3
c/ /'_ --- Dept. of Biostatistics     2200 Cph. N
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```