Here we are explaining how to write an R program to extract a specific column from a data frame using a column name. Here we are using a built-in function data.frame() for this. A data frame is used for storing data tables which has a list of vectors with equal length. The data frames are created by function data.frame(), which has tightly coupled collections of variables. The syntax of this function is
data.frame(…, row.names = NULL, check.rows = FALSE,check.names = TRUE, fix.empty.names = TRUE,stringsAsFactors = default.stringsAsFactors())
Where dots(...) indicates the arguments are of either the form value or tag = value and row. name is a NULL or a single integer or character string.
Below are the steps used in the R program to extract specific columns from a data frame using a column name. In this R program, we directly give the data frame to a built-in function. Here we are using variables E, N, S, A, Q for holding different types of vectors. Call the function data.frame() for creating dataframe.
STEP 1: Assign variables E,N,S,A,Q with vector values
STEP 2: First print original vector values
STEP 3: Call the function data.frame for extracting specific column as data.frame(E$N,E$S)
STEP 4: Assign variable result with the result of data.frame function
STEP 5: print the variable result which holding the result
E = data.frame( N = c('Jhon', 'Hialy', 'Albert', 'James', 'Delma'), S = c(10, 9.5, 12.2, 11, 8), A = c(2, 1, 2, 4, 1), Q = c('yes', 'no', 'yes', 'no', 'no') ) print("Original dataframe:") print(E) print("Extract Specific columns:") result <- data.frame(E$N,E$S) print(result)
 "Original dataframe:" name score attempts qualify 1 Jhon 10 2 yes 2 Hialy 9.5 1 no 3 Albert 12.2 2 yes 4 James 11 4 no 5 Delma 8 1 no  "Extract Specific columns:" E.N E.S 1 Jhon 10 2 Hialy 9.5 3 Albert 12.2 4 James 11 5 Delma 8