R data types
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This document discusses R data types. It explains that in R, variables are assigned objects that determine the data type. The main data types covered are scalars, vectors, matrices, factors, data frames, and lists. Vectors store one-dimensional arrays, matrices are two-dimensional arrays of the same type, factors represent categorical variables, data frames contain different data types, and lists store ordered collections of varied objects. Examples are provided for creating each type of data structure in R.
R data types
- 2. Beauty of R Data Types OBJECT
- 3. R - objects In R programming language, • Variables are not declared as some data types • Variables are assigned with R – objects • The data type of R-object becomes the data type of the variable. NOTE: -> everything is just R - object
- 4. Basic Data Types in R R Programming works with various data types, –Scalars –Vectors –Matrices –Factors –Data frames –Lists
- 5. Basic Types • Numeric • Integers • Logical • Characters
- 6. VECTORS • A vector is a one-dimensional array. • We can create a vector with all the basic data type we learnt before. • The simplest way to build a vector in R, is to use the ‘ c ‘ command. Ex: num_vec <- c(1, 2, 3, 4) chr_vec <- c(“a”, ”b”, ”c”)
- 7. MATRIX • A matrix is a 2-dimensional array that has m number of rows and n number of columns. • In other words, matrix is a combination of two or more vectors with the same data type. NOTE: In R, more than two-dimensional arrays can also be created Semantic: matrix( data, nrow, ncol, byrow = TRUE/FALSE)
- 8. FACTORS • Factor is a variable in R which take on a limited number of different values; such variables are often referred to as categorical variables. • In other words, R stores categorical variables into a factor. Semantic: factor(x = character(), levels, labels = levels, ordered = is.ordered(x) )
- 9. Data frames • A data frame is a list of vectors which are of equal length. • A matrix contains only one type of data, while a data frame accepts different data types (numeric, character, factor, etc.). Semantic: data.frame( df, stringsAsFactors = TRUE)
- 10. Lists • A list store many kinds of object in the order expected. • It can include matrices, vectors data frames or lists. • A list is similar; we can store a collection of objects and use them when we need them. Semantic: list( element_1, element_2, ... ) arguments: -element_1: store any type of R object -...: pass as many objects as specifying. Each object needs to be separated by a comma.