R script

Author: jonsan21

1.Introduction/Introduction.R

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+#A first session
+
+set.seed(476)
+x<-rnorm(100)
+head(x)
+mean(x)
+sd(x)
+min(x)
+max(x)
+
+#Basic operations
+
+2+2
+7*17
+sqrt(9)
+3^3
+log(7)
+log10(7)
+
+#Precision
+
+sin(pi/2)
+pi
+options(digits=22)
+pi
+
+#Infinity or not defined, and missings
+
+1/0  
+2*Inf
+-1/0
+0/0
+c(1,2,3,NA,5)
+mean(c(1,2,3,NA,5))
+
+#Assignments to variables
+
+rm(list=ls())
+options(digits=7)
+x <- 5
+x
+# x=5 can be used; not recommended
+x*x
+y <- x+5
+ls()
+rm(x)
+ls()
+
+#Internal help function
+
+?mean    # shorthand for help(mean)
+example(mean)
+??"fitting linear model"   # shorthand for 
+# help.search("fitting linear model")
+#Manuals
+
+help.start()