Hello, R friends...
I am very new to R, and I need some help. I am trying to construct a simulation for my dissertation. I need to create 1000 datasets of 1000 subjects with the following variables... Treatment variable - Drawn from a binomial distribution (1 run, prob=.13) Covariate 1 - Drawn from a normal distribution (mean=100, sd=16) Covariate 2 - Drawn from a normal distribution (mean=200, sd=9) Covariates 1 and 2 need to be correlated (say, r=.80) Covariate 3 - Drawn from a binomial distribution (1 run, prob=.5) Covariate 4 - Drawn from a distribution of discrete variables where 1 has an 80% chance of being selected, 2 - 10%, 3 - 5% and 4 - 5%. This variable would need to be recoded into 4 binary variables. Covariate 5 - Drawn from a normal distribution (mean=84, sd=2) Covariate 6 - Drawn from a binomial distribution (1 run, prob=.15) Covariate 6 needs to correlate with Covariate 2 (r=.70, or so) I need each dataset saved as a new datafile with an iterative filename (e.g. sample1, sample2, etc.). Please help! Thanks! Shane ______________________________________________ [hidden email] 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. |
What have you tried so far?
It is often helpful to begin with a much simpler problem, then add complexity incrementally until you've constructed the desired model. Best wishes. Charles Annis, P.E. [hidden email] 561-352-9699 http://www.StatisticalEngineering.com -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Shane Phillips Sent: Friday, April 15, 2011 2:50 PM To: [hidden email] Subject: [R] Monte Carlo Simulation Hello, R friends... I am very new to R, and I need some help. I am trying to construct a simulation for my dissertation. I need to create 1000 datasets of 1000 subjects with the following variables... Treatment variable - Drawn from a binomial distribution (1 run, prob=.13) Covariate 1 - Drawn from a normal distribution (mean=100, sd=16) Covariate 2 - Drawn from a normal distribution (mean=200, sd=9) Covariates 1 and 2 need to be correlated (say, r=.80) Covariate 3 - Drawn from a binomial distribution (1 run, prob=.5) Covariate 4 - Drawn from a distribution of discrete variables where 1 has an 80% chance of being selected, 2 - 10%, 3 - 5% and 4 - 5%. This variable would need to be recoded into 4 binary variables. Covariate 5 - Drawn from a normal distribution (mean=84, sd=2) Covariate 6 - Drawn from a binomial distribution (1 run, prob=.15) Covariate 6 needs to correlate with Covariate 2 (r=.70, or so) I need each dataset saved as a new datafile with an iterative filename (e.g. sample1, sample2, etc.). Please help! Thanks! Shane ______________________________________________ [hidden email] 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. ______________________________________________ [hidden email] 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. |
Here's a script of what I have so far. I have a few problems. First, the correlations. Next, recoding that categorical variable into dichotomous variables. Finally, the iterative filename thing.
Thanks! S -----Original Message----- From: Charles Annis, P.E. [mailto:[hidden email]] Sent: Friday, April 15, 2011 3:01 PM To: Shane Phillips; [hidden email] Subject: RE: [R] Monte Carlo Simulation What have you tried so far? It is often helpful to begin with a much simpler problem, then add complexity incrementally until you've constructed the desired model. Best wishes. Charles Annis, P.E. [hidden email] 561-352-9699 http://www.StatisticalEngineering.com -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Shane Phillips Sent: Friday, April 15, 2011 2:50 PM To: [hidden email] Subject: [R] Monte Carlo Simulation Hello, R friends... I am very new to R, and I need some help. I am trying to construct a simulation for my dissertation. I need to create 1000 datasets of 1000 subjects with the following variables... Treatment variable - Drawn from a binomial distribution (1 run, prob=.13) Covariate 1 - Drawn from a normal distribution (mean=100, sd=16) Covariate 2 - Drawn from a normal distribution (mean=200, sd=9) Covariates 1 and 2 need to be correlated (say, r=.80) Covariate 3 - Drawn from a binomial distribution (1 run, prob=.5) Covariate 4 - Drawn from a distribution of discrete variables where 1 has an 80% chance of being selected, 2 - 10%, 3 - 5% and 4 - 5%. This variable would need to be recoded into 4 binary variables. Covariate 5 - Drawn from a normal distribution (mean=84, sd=2) Covariate 6 - Drawn from a binomial distribution (1 run, prob=.15) Covariate 6 needs to correlate with Covariate 2 (r=.70, or so) I need each dataset saved as a new datafile with an iterative filename (e.g. sample1, sample2, etc.). Please help! Thanks! Shane ______________________________________________ [hidden email] 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. ______________________________________________ [hidden email] 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. |
In reply to this post by Shane Phillips
Hi Shane,
See ?rbinom, ?rnorm, ?mvrnorm (in the MASS package), ?sample, ?for and ?write.table Best, Ista On Fri, Apr 15, 2011 at 2:49 PM, Shane Phillips <[hidden email]> wrote: > Hello, R friends... > > I am very new to R, and I need some help. I am trying to construct a simulation for my dissertation. > > I need to create 1000 datasets of 1000 subjects with the following variables... > > Treatment variable - Drawn from a binomial distribution (1 run, prob=.13) > Covariate 1 - Drawn from a normal distribution (mean=100, sd=16) > Covariate 2 - Drawn from a normal distribution (mean=200, sd=9) > Covariates 1 and 2 need to be correlated (say, r=.80) > Covariate 3 - Drawn from a binomial distribution (1 run, prob=.5) > Covariate 4 - Drawn from a distribution of discrete variables where 1 has an 80% chance of being selected, 2 - 10%, 3 - 5% and 4 - 5%. This variable would need to be recoded into 4 binary variables. > Covariate 5 - Drawn from a normal distribution (mean=84, sd=2) > Covariate 6 - Drawn from a binomial distribution (1 run, prob=.15) > Covariate 6 needs to correlate with Covariate 2 (r=.70, or so) > > I need each dataset saved as a new datafile with an iterative filename (e.g. sample1, sample2, etc.). > > Please help! > > Thanks! > > Shane > > ______________________________________________ > [hidden email] 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. > -- Ista Zahn Graduate student University of Rochester Department of Clinical and Social Psychology http://yourpsyche.org ______________________________________________ [hidden email] 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. |
In reply to this post by Shane Phillips
On 15 April 2011 12:03, Shane Phillips <[hidden email]> wrote:
> Here's a script of what I have so far. I have a few problems. First, the correlations. Next, recoding that categorical variable into dichotomous variables. Finally, the iterative filename thing. > Where? Perhaps give the list one question at a time? Here's a start for one of the questions, selected (almost) at random. Give 80% of people a score of 1 on a x1, and 20% of people zero. tempVar <- runif(1000) x1 <- ifelse(tempVar < 0.8, 1, 0) rm(tempVar) Tell us how far you've got. Do you need to know about write.table() for the saving the files, or is the problem with splitting a large file, or generating the 1000 names ... Jeremy -- Jeremy Miles Psychology Research Methods Wiki: www.researchmethodsinpsychology.com ______________________________________________ [hidden email] 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. |
In reply to this post by Charles Annis, P.E.
I apologize for my last post. here is the script I forgot to paste!
subject=1:1000 treat=rbinom(1*1000,1,.13) gender=rbinom(1*1000,1,.5) eth=runif(1*1000, min=1, max=4) cogat=rnorm(1*1000, 100, 16) map=rnorm(1*1000, 200, 9) growth=0 simtest=data.frame (subject=subject, treat=treat, gender=gender, eth=round(eth,digits=0), cogat=round(cogat,digits=0),map=round(map,digits=0),growth) simtest<-transform(simtest, growth=rnorm(1000,m=ifelse(treat==0,0.1,0.5),s=0.03)) simtest Once again the issues are the correlations, the recoding of the categorical variable and the iterations. Thanks to all who have helped so far! You are all so smart! S ________________________________________ From: Charles Annis, P.E. [[hidden email]] Sent: Friday, April 15, 2011 3:00 PM To: Shane Phillips; [hidden email] Subject: RE: [R] Monte Carlo Simulation What have you tried so far? It is often helpful to begin with a much simpler problem, then add complexity incrementally until you've constructed the desired model. Best wishes. Charles Annis, P.E. [hidden email] 561-352-9699 http://www.StatisticalEngineering.com -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Shane Phillips Sent: Friday, April 15, 2011 2:50 PM To: [hidden email] Subject: [R] Monte Carlo Simulation Hello, R friends... I am very new to R, and I need some help. I am trying to construct a simulation for my dissertation. I need to create 1000 datasets of 1000 subjects with the following variables... Treatment variable - Drawn from a binomial distribution (1 run, prob=.13) Covariate 1 - Drawn from a normal distribution (mean=100, sd=16) Covariate 2 - Drawn from a normal distribution (mean=200, sd=9) Covariates 1 and 2 need to be correlated (say, r=.80) Covariate 3 - Drawn from a binomial distribution (1 run, prob=.5) Covariate 4 - Drawn from a distribution of discrete variables where 1 has an 80% chance of being selected, 2 - 10%, 3 - 5% and 4 - 5%. This variable would need to be recoded into 4 binary variables. Covariate 5 - Drawn from a normal distribution (mean=84, sd=2) Covariate 6 - Drawn from a binomial distribution (1 run, prob=.15) Covariate 6 needs to correlate with Covariate 2 (r=.70, or so) I need each dataset saved as a new datafile with an iterative filename (e.g. sample1, sample2, etc.). Please help! Thanks! Shane ______________________________________________ [hidden email] 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. ______________________________________________ [hidden email] 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. |
In reply to this post by Jeremy Miles-2
See below:
-- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 -----Original Message----- From: Jeremy Miles <[hidden email]> Date: Fri, 15 Apr 2011 14:17:13 -0700 To: Shane Phillips <[hidden email]> Cc: "[hidden email]" <[hidden email]> Subject: Re: [R] Monte Carlo Simulation >On 15 April 2011 12:03, Shane Phillips <[hidden email]> wrote: >> Here's a script of what I have so far. I have a few problems. First, >>the correlations. Next, recoding that categorical variable into >>dichotomous variables. Finally, the iterative filename thing. >> > > Where? > >Perhaps give the list one question at a time? > >Here's a start for one of the questions, selected (almost) at random. >Give 80% of people a score of 1 on a x1, and 20% of people zero. > >tempVar <- runif(1000) >x1 <- ifelse(tempVar < 0.8, 1, 0) >rm(tempVar) x1 <- rbinom(1000,1,0.8) > > >Tell us how far you've got. Do you need to know about write.table() >for the saving the files, or is the problem with splitting a large >file, or generating the 1000 names ... > > >Jeremy > > > >-- >Jeremy Miles >Psychology Research Methods Wiki: www.researchmethodsinpsychology.com > >______________________________________________ >[hidden email] 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. ______________________________________________ [hidden email] 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. |
In reply to this post by Shane Phillips
The filenames can be done within a loop, like this:
for (id in 1:1000) { ## the filename fname <- paste('sample', formatC(id,width=4,flag='0'),'.tsv',sep='') ## more stuff } -Don -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 -----Original Message----- From: Shane Phillips <[hidden email]> Date: Fri, 15 Apr 2011 11:49:48 -0700 To: "[hidden email]" <[hidden email]> Subject: [R] Monte Carlo Simulation >Hello, R friends... > >I am very new to R, and I need some help. I am trying to construct a >simulation for my dissertation. > >I need to create 1000 datasets of 1000 subjects with the following >variables... > >Treatment variable - Drawn from a binomial distribution (1 run, prob=.13) >Covariate 1 - Drawn from a normal distribution (mean=100, sd=16) >Covariate 2 - Drawn from a normal distribution (mean=200, sd=9) >Covariates 1 and 2 need to be correlated (say, r=.80) >Covariate 3 - Drawn from a binomial distribution (1 run, prob=.5) >Covariate 4 - Drawn from a distribution of discrete variables where 1 has >an 80% chance of being selected, 2 - 10%, 3 - 5% and 4 - 5%. This >variable would need to be recoded into 4 binary variables. >Covariate 5 - Drawn from a normal distribution (mean=84, sd=2) >Covariate 6 - Drawn from a binomial distribution (1 run, prob=.15) >Covariate 6 needs to correlate with Covariate 2 (r=.70, or so) > >I need each dataset saved as a new datafile with an iterative filename >(e.g. sample1, sample2, etc.). > >Please help! > >Thanks! > >Shane > >______________________________________________ >[hidden email] 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. ______________________________________________ [hidden email] 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. |
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