[R] generating points over a function, its possible???
Roger Peng
rpeng at stat.ucla.edu
Fri Jun 21 21:55:01 CEST 2002
How about this?
f <- function(x) { 9.7909 - 0.035 * x }
x <- 1:100 ## or whatever
sigma <- sqrt(13.01403)
sim.y <- f(x) + sigma * rnorm(length(x))
This uses Normal errors, which (by your picture) seems like what you want.
You might want to use set.seed() so that you can reproduce the results.
-roger
_______________________________
UCLA Department of Statistics
rpeng at stat.ucla.edu
http://www.stat.ucla.edu/~rpeng
On Fri, 21 Jun 2002, Ronaldo Reis Jr. wrote:
> Hi,
> I have a new (for me) situation.
> I have a function for one linear model:
> y = 9.7909-0.035*x
> I have the variance of system
> var = 13.01403
> Is possible to create a random vector points of Y (simulating the real data)
> over this curve using the function and the variance? I need this to a
> discipline.
>
> I have this:
>
> | \
> | \ -> y = 9.7909-0.035*x and var = 13.014
> | \
> | \
> | \
> | \
> |__________
>
> I need something like this (generate this points):
>
> |* \*
> | * \**
> | **\ *
> | *\ **
> | * \*
> | * \ *
> | *\
> |____________
>
> Thanks for all
> Ronaldo
> --
> "It ain't over until it's over."
> -- Casey Stengel
> --
> | //|\\ [*****************************][*******************]
> || ( õ õ ) [Ronaldo Reis Júnior ][PentiumIII-600 ]
> | V [ESALQ/USP-Entomologia, CP-09 ][HD: 30 + 10 Gb ]
> || / l \ [13418-900 Piracicaba - SP ][RAM: 128 Mb ]
> | /(lin)\ [Fone: 19-429-4199 r.229 ][Video: SiS620-8Mb ]
> ||/(linux)\ [chrysopa at insecta.ufv.br ][Modem: Pctel-onboar]
> |/ (linux) \[ICQ#: 5692561 ][SO: CL 7.0 (2.2.19)]
> || ( x ) [*****************************][*******************]
> ||| _/ \_Powered by Conectiva Linux 7.0 D+:) | Lxuser#: 205366
>
>
> -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
> r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
> Send "info", "help", or "[un]subscribe"
> (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch
> _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
>
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
More information about the R-help
mailing list