Introduction to R: Ein unkommentiertes Skript

#Basic Commands

x <- c(1,2,3,4,5)
x

x = c(5,3,9)
x

y = c(3,7,2)

class(x)
length(x)

x+y
z = x+y
z

ls()
rm(z)
ls()
rm(list=ls())
ls()

?matrix
x = matrix(data=c(1,2,3,4), nrow=2, ncol=2)
x
x = matrix(c(1:6), 2, 2)
x
matrix(c(1:6), 2, 2, byrow=TRUE)

sqrt(x)
x^2

x = rnorm(50)
x
x = rnorm(50)
x
set.seed(123)
x = rnorm(50)
x
set.seed(123)
x = rnorm(50)
x
y = x+rnorm(50, mean=50, sd=.1)
cor(x,y)

#Gaphics

plot(x,y)
plot(x,y, xlab="x-axis", ylab="y-axis", main="Plot of X vs Y")

?contour
x = seq(-pi, pi, length=50)
y=x
f=outer(x,y, function(x,y) cos(y)/(1+x^2))
contour(x,y,f)
contour(x,y,f, nlevels=45, add=T)
fa = (f-t(f))/2
contour(x,y,fa,nlevels=15)

image(x,y,fa)
persp(x,y,fa)
persp(x,y,fa, theta=30)

#Indexing Data

A = matrix(1:16,4,4)
A
A[2,3]
A[c(1,3),c(2:4)]
A[2,]
A[,2]
A[,1:2]
A[-3,]
dim(A)
A = A[-4,]
dim(A)
dim(A)[1]

#Loading Data and Plotting

gallup = read.csv("http://www.utexas.edu/cola/_webservices/policyagendas/mip/instances.csv?from=1945&to=2012")
View(gallup)

plot(Year, Percentage)
plot(gallup$Year, gallup$Percentage)
plot(gallup$MajorTopic, gallup$Percentage)
plot(as.factor(gallup$MajorTopic), gallup$Percentage)
hist(gallup$Percentage)
pairs(gallup)

summary(gallup)
summary(gallup$MajorTopic)

write.csv(gallup, "gallup.csv")