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R video tutorial number 2

Filed in Encyclopedia ,R
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READ TEXT FILES, RUN MODELS

rtut2.gif

The Decision Science News R video tutorials continue with number 2. (If you missed that last one, you will want to watch R Video Tutorial Number 1 first.) The Goldstein pedometer dataset can be downloaded from http://www.dangoldstein.com/flash/Rtutorial2/pedometer.csv

High Res Version: http://www.dangoldstein.com/flash/Rtutorial2/Rtutorial2.html

Topics covered this week include:

  • Tricking R into starting in your working directory
  • Reading in text files
  • Accessing columns in data frames
  • Creating histograms
  • Side effects and optional parameters of function calls
  • Fitting simple linear models
  • Adding least-squares and loess lines to plots

The commands in the tutorial are:

myData=read.table("pedometer.csv", header=TRUE, sep=",")
x=hist(myData$Steps,col="lightblue")
x=hist(myData$Steps,breaks=20,col="lightblue")
plot(myData$Steps ~ myData$Observation,col="blue")
myModel=lm(myData$Steps ~ myData$Observation)
summary(myModel)
lines(fitted(myModel))
lines(fitted(loess(myModel)),col="red")

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