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

[Roger Peng]

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."
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