day5-halfday
mieu
December 1, 2015
My first R Markdown document
loading the car dataset
In this section, I shall explain how to load the build-in dataset named mtcars.
str(mtcars)## 'data.frame': 32 obs. of 11 variables:
## $ mpg : num 21 21 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 ...
## $ cyl : num 6 6 4 6 8 6 8 4 4 6 ...
## $ disp: num 160 160 108 258 360 ...
## $ hp : num 110 110 93 110 175 105 245 62 95 123 ...
## $ drat: num 3.9 3.9 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 ...
## $ wt : num 2.62 2.88 2.32 3.21 3.44 ...
## $ qsec: num 16.5 17 18.6 19.4 17 ...
## $ vs : num 0 0 1 1 0 1 0 1 1 1 ...
## $ am : num 1 1 1 0 0 0 0 0 0 0 ...
## $ gear: num 4 4 4 3 3 3 3 4 4 4 ...
## $ carb: num 4 4 1 1 2 1 4 2 2 4 ...plotting graph wt against mpg
ggplot(mtcars, aes(wt, mpg)) + geom_point(aes(colour=factor(cyl), size =qsec))
plotting graph wt against mpg
ggplot(mtcars, aes(wt, mpg)) + geom_point(aes(colour=factor(cyl), size =qsec)) plotting graph wt against mpg
introduction
First simulate code
x<-rnorm(100)
y<-x+rnorm(100, sd=0.5)plot(x,y, main = "My Simulated Data")
plotting graph wt against mpg The mean of the miles-per-gallon in the mtcars dataset is 20.090625.
# generate some random data
dat = matrix(runif(100000), ncol=5)
dat[, 3] = -.2 * dat[, 1] + .8 * dat[, 2] # to make the plot less boringpairs(dat)