Lab 0 - Introduction to R

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The lab sheet can be found here.

Support Material §

• A (very) short introduction to R.

R Cheatsheets §

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• Graph Parameters CheatSheet.

• Base R CheatSheet.

• Data Transformation CheatSheet.

• Full manual here.

• Short reference card.

• Examples here.

• Typical user wiki.

Notes §

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• R is case-sensitive, so view doesn’t work but View does.

• When a data point is not available we use NA: j = c(1,2,NA).

  • If you want to compute anyways: max(j, na.rm=TRUE).

Creating Scatterplots §

• Column name:
  • plot(mydata$column1, mydata$column2)
• Column location:
  • plot(mydata[,9], mydata[,11])
• Histogram:
  • hist(mydata$temp)
• Line plot:
  • plot(mydata$temp, type="l")
• Plot colours, for example X and Y according to temperature:
  • plot(mydata$X, mydata$Y, col=mydata$temp)
• Statistics:
  • Mean, median, maximum and minimum:
    • meantemp = mean(mydata$temp)
• Write to a file:
  • write.csv(meantemp, file = "output.csv")
• Build a linear model:

  plot(mydata$temp, mydata$ISI)
  lmfire=line(mydata$ISI~mydata$temp)
  abline(coef(lmfire))

Commands §

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mydata = read.csv('/Users/pietra/projects/university/year3/cs3002/lab1/forestfires.csv', sep=',')
 
plot(mydata)
View(mydata)
 
plot(mydata$column1, mydata$column2)
plot(mydata[,9], mydata[,11])
hist(mydata$temp)
plot(mydata$temp, type="l")
plot(mydata$X, mydata$Y, col=mydata$temp)
meantemp = mean(mydata$temp)
write.csv(meantemp, file = "output.csv")
 
plot(mydata$temp, mydata$ISI)
lmfire=line(mydata$ISI~mydata$temp)
abline(coef(lmfire))