Hello,
I would like to write a loop to 1) run 100 linear regressions, and 2)
compile the slopes of all regression into one vector. Sample input data
are:
y1<-rnorm(100, mean=0.01, sd=0.001)
y2<-rnorm(100, mean=0.1, sd=0.01)
x<-(c(10,400))
#I have gotten this far with the loop
for (i in 1:100) {
#create the linear model for each data set
model1<-lm(c(y1[i],y2[i])~x)
slope1<-model1$coefficients[2]
}
How can I compile the slopes from all 100 regressions into one vector?
Thanks,
Jake
[[alternative HTML version deleted]]
Create an output vector to hold your slopes before starting the loop, then
use your index i to place each new slope in the appropriate position in your
vector.
y1<-rnorm(100, mean=0.01, sd=0.001)
y2<-rnorm(100, mean=0.1, sd=0.01)
x<-(c(10,400))
my.slopes = vector("numeric",100) # initialize a numeric vector,
length
100, filled with zeros initially
for (i in 1:100) {
#create the linear model for each data set
model1<-lm(c(y1[i],y2[i])~x)
slope1<-model1$coefficients[2]
my.slopes[i] = slope1 # stick each new slope value into my.slopes[i]
}
You could skip the slope1 <- model1$coefficients[2] step and just put the
slope directly into my.slopes[i] as well.
On Fri, Sep 16, 2011 at 3:25 PM, <Beaulieu.Jake@epamail.epa.gov> wrote:
> Hello,
>
> I would like to write a loop to 1) run 100 linear regressions, and 2)
> compile the slopes of all regression into one vector. Sample input data
> are:
>
> y1<-rnorm(100, mean=0.01, sd=0.001)
> y2<-rnorm(100, mean=0.1, sd=0.01)
>
> x<-(c(10,400))
>
> #I have gotten this far with the loop
>
> for (i in 1:100) {
>
> #create the linear model for each data set
> model1<-lm(c(y1[i],y2[i])~x)
> slope1<-model1$coefficients[2]
> }
>
> How can I compile the slopes from all 100 regressions into one vector?
>
> Thanks,
> Jake
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
--
___________________________
Luke Miller
Postdoctoral Researcher
Marine Science Center
Northeastern University
Nahant, MA
(781) 581-7370 x318
[[alternative HTML version deleted]]
Just a minor aside; I would have done my.slopes <- numeric(100) Note that:> class(numeric(5))[1] "numeric" -Don -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 On 9/16/11 12:37 PM, "Luke Miller" <millerlp at gmail.com> wrote:>Create an output vector to hold your slopes before starting the loop, then >use your index i to place each new slope in the appropriate position in >your >vector. > >y1<-rnorm(100, mean=0.01, sd=0.001) >y2<-rnorm(100, mean=0.1, sd=0.01) > >x<-(c(10,400)) > >my.slopes = vector("numeric",100) # initialize a numeric vector, length >100, filled with zeros initially > >for (i in 1:100) { > >#create the linear model for each data set >model1<-lm(c(y1[i],y2[i])~x) >slope1<-model1$coefficients[2] >my.slopes[i] = slope1 # stick each new slope value into my.slopes[i] >} > >You could skip the slope1 <- model1$coefficients[2] step and just put the >slope directly into my.slopes[i] as well. > >On Fri, Sep 16, 2011 at 3:25 PM, <Beaulieu.Jake at epamail.epa.gov> wrote: > >> Hello, >> >> I would like to write a loop to 1) run 100 linear regressions, and 2) >> compile the slopes of all regression into one vector. Sample input data >> are: >> >> y1<-rnorm(100, mean=0.01, sd=0.001) >> y2<-rnorm(100, mean=0.1, sd=0.01) >> >> x<-(c(10,400)) >> >> #I have gotten this far with the loop >> >> for (i in 1:100) { >> >> #create the linear model for each data set >> model1<-lm(c(y1[i],y2[i])~x) >> slope1<-model1$coefficients[2] >> } >> >> How can I compile the slopes from all 100 regressions into one vector? >> >> Thanks, >> Jake >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help at r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide >> http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> > > > >-- >___________________________ >Luke Miller >Postdoctoral Researcher >Marine Science Center >Northeastern University >Nahant, MA >(781) 581-7370 x318 > > [[alternative HTML version deleted]] > >______________________________________________ >R-help at r-project.org mailing list >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide >http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code.
You did ask for a loop, but if you are willing to consider sapply(), the result you want can be obtained with a single (admittedly long) command:> slope<-sapply(1:100, function(x) lm(c(rnorm(1, mean=.01, sd=.001),rnorm(1, mean=.1, sd=.01))~c(10,400))$coefficients[2])> head(slope)c(10, 400) c(10, 400) c(10, 400) c(10, 400) c(10, 400) c(10, 400) 0.0001994346 0.0002118383 0.0002729246 0.0002249865 0.0002323564 0.0002113820 If the "c(10, 400)" labels are distracting, you can replace them with consecutive integers:> names(slope)<-1:100 > head(slope)1 2 3 4 5 6 0.0001994346 0.0002118383 0.0002729246 0.0002249865 0.0002323564 0.0002113820 ---------------------------------------------- David L Carlson Associate Professor of Anthropology Texas A&M University College Station, TX 77843-4352 -----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of MacQueen, Don Sent: Friday, September 16, 2011 6:58 PM To: Luke Miller; Beaulieu.Jake at epamail.epa.gov Cc: r-help at r-project.org Subject: Re: [R] Help writing basic loop Just a minor aside; I would have done my.slopes <- numeric(100) Note that:> class(numeric(5))[1] "numeric" -Don -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 On 9/16/11 12:37 PM, "Luke Miller" <millerlp at gmail.com> wrote:>Create an output vector to hold your slopes before starting the loop, then >use your index i to place each new slope in the appropriate position in >your >vector. > >y1<-rnorm(100, mean=0.01, sd=0.001) >y2<-rnorm(100, mean=0.1, sd=0.01) > >x<-(c(10,400)) > >my.slopes = vector("numeric",100) # initialize a numeric vector, length >100, filled with zeros initially > >for (i in 1:100) { > >#create the linear model for each data set >model1<-lm(c(y1[i],y2[i])~x) >slope1<-model1$coefficients[2] >my.slopes[i] = slope1 # stick each new slope value into my.slopes[i] >} > >You could skip the slope1 <- model1$coefficients[2] step and just put the >slope directly into my.slopes[i] as well. > >On Fri, Sep 16, 2011 at 3:25 PM, <Beaulieu.Jake at epamail.epa.gov> wrote: > >> Hello, >> >> I would like to write a loop to 1) run 100 linear regressions, and 2) >> compile the slopes of all regression into one vector. Sample input data >> are: >> >> y1<-rnorm(100, mean=0.01, sd=0.001) >> y2<-rnorm(100, mean=0.1, sd=0.01) >> >> x<-(c(10,400)) >> >> #I have gotten this far with the loop >> >> for (i in 1:100) { >> >> #create the linear model for each data set >> model1<-lm(c(y1[i],y2[i])~x) >> slope1<-model1$coefficients[2] >> } >> >> How can I compile the slopes from all 100 regressions into one vector? >> >> Thanks, >> Jake >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help at r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide >> http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> > > > >-- >___________________________ >Luke Miller >Postdoctoral Researcher >Marine Science Center >Northeastern University >Nahant, MA >(781) 581-7370 x318 > > [[alternative HTML version deleted]] > >______________________________________________ >R-help at r-project.org mailing list >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide >http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code.______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
