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

[Peter Dalgaard BSA]

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   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907
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