[R] looking for a more efficient R code.

[Daniel Nordlund]

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch [mailto:r-help-bounces at stat.math.ethz.ch]
> On Behalf Of Taka Matzmoto
> Sent: Monday, June 26, 2006 5:21 PM
> To: r-help at stat.math.ethz.ch
> Subject: [R] looking for a more efficient R code.
> 
> Dear R-users
> 
> I have four simple linear models, which are all in the form of a*X+b
> The estimated parameter vectors are
> 
> a <- c(1,2,3,4)
> b <- c(4,3,2,1)
> 
> My goal is to draw a plot where x-axis is X (range from -100 to 100) and
> y-axis is the sum of
> all four linear models
> 
> X <- seq(-100,100, length=10000)
> plot(X, sum of the four linear functions)
> 
> I started with a function for summing
> 
> summing <- function(a,b)
> {temp <-0;
> for (i in 1:length(a))
> temp <- temp + a[i]*X+b[i]
> }
> 
> plot(X, summing(a,b))
> 
> I am a R beginner.  I am looking for a more efficient R code.
> 
> Any help or advice will be appreciated.
> 
> Taka,
> 

Taka,

I won't claim more efficient, that is for you to decide.  But you might try something like:

plot(x, colSums(t(x %*% t(b)) + a))

Dan

Daniel Nordlund
Bothell, WA