# Goals: A first look at R objects - vectors, lists, matrices, data frames. # To make vectors "x" "y" "year" and "names" x <- c(2,3,7,9) y <- c(9,7,3,2) year <- 1990:1993 names <- c("payal", "shraddha", "kritika", "itida") # Accessing the 1st and last elements of y -- y[1] y[length(y)] # To make a list "person" -- person <- list(name="payal", x=2, y=9, year=1990) person # Accessing things inside a list -- person$name person$x # To make a matrix, pasting together the columns "year" "x" and "y" # The verb cbind() stands for "column bind" cbind(year, x, y) # To make a "data frame", which is a list of vectors of the same length -- D <- data.frame(names, year, x, y) nrow(D) # Accessing one of these vectors D$names # Accessing the last element of this vector D$names[nrow(D)] # Or equally, D$names[length(D$names)]