# http://www.r-project.org/ # http://cran.r-project.org/ # http://www.google.com/ ### Environment Functions. q() help() help("ls") help.start() # Or Web help pages. a <- 1 .a <- 2 ls() ls(all.names = TRUE) a .a rm(list = ls()) ls() ls(all.names = TRUE) rm(list = ls(all.names = TRUE)) ls(all.names = TRUE) getwd() setwd("C:/Documents and Settings/snoweye/Desktop/") setwd("C:\\Documents and Settings\\snoweye\\Desktop\\") # Or by clicking from the top menu "File -> Change dir ..." ### Library Functions. search() library() library("base") demo() demo("graphics") demo("image") ### Basic notation. b <- c("a", "string", "vector", "in", "b") length(b) d <- matrix(1:15, nrow = 3, ncol = 5) dim(d) d d[c(1, 3), ] d[-2,] d[, 1:2] e <- data.frame(v1 = 1:3, v2 = 4:6, v3 = 7:9) names(e) colnames(e) rownames(e) str(f.1) e[c(1, 3), ] e[-2,] e[, 1:2] e$v1 e[, c("v1", "v3")] ### I/O Functions. save(list = ls(), file = "all.rda") rm(list = ls(all.names = TRUE)) load("all.rda") ls(all.names = TRUE) write.csv(e, file = "e-1.csv") f.1 <- read.csv("e-1.csv") write.csv(e, file = "e-2.csv", row.names = FALSE) f.2 <- read.csv("e-2.csv") ### Description Statistics. sum(e) min(e) max(e) mean(e) var(e) median(e) quantile(e, prob = c(0.25, 0.75)) ### Distribution Related Functions. dnorm(0, mean = 0, sd = 1) qnorm(0) pnorm(0) set.seed(123) rnorm(10) ### Plot Functions. plot() lines() points() # http://addictedtor.free.fr/graphiques/ par() axis() box() main() legend() colors() ### Exercises. # Ex 1. rm(list = ls()) set.seed(1234) x <- 1:30 y1 <- rnorm(30) summary(y1) (y2 <- rnorm(30)) plot(x, y1) # Ex 2. windows() par(mfrow = c(2, 2)) plot(x, y1, type = "n", xlab = "x", ylab = "y", main = "Exercise 2") points(x, y1, col = "green", pch = 2) lines(x, y2, col = 4, lty = 2) legend(3, 2.7, c("y1", "y2"), lty = c(0, 2), pch = c(2, -1), col = c("green", 4)) boxplot(y1, y2) hist(y1) plot(y1, y2) ### 5 minutes paper: answering the following questions. # 1. (Notations) # What do the functions of "seq()" and "rep()" for? # What are the results of "seq(1, 5)" and "rep(1, 5)"? # # 2. (Distribution) # a. Find the distribution related functions for Chi Square, # t, F, Binomial, and Poisson distributions. List them by objectives: # # | density/mass | quantile | cdf | radom number # ---------+--------------+----------+-------------+------------- # Normal | dnorm() | qnorm() | pnorm() | rnorm() # Chi^2 | | | | # t | | | | # F | | | | # Binomial | | | | # Poisson | | | | # # b. What library do these functions belong to? # # 3. (Probability) # Are the following statements equal and why? # a. "1 - qnorm(0.95)" and "qnorm(0.05, lower.tail = FALSE)" # b. "1 - pexp(0.25)" and "pexp(0.25, lower.tail = FALSE)" # # 4. (Graph) # a. What library do these functions "hist()" and "boxplot()" belong to? # b. What are these functions "pdf()", "bitmap()", and "png()" for? # # 5. (Statistics) # a. What purpose are these functions "wilcox.test", "anova()", "lm()" for? # b. Use Google to find which library the function "lme()" belong to. #