R tutorial and example for Beginners - R Program to extract specific column from a data frame using column name

R Program to extract specific column from a data frame using column name

How to extract specific column from a data frame using column name

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.

How to extract a specific column from a data frame using column name in the R program

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.

ALGORITHM

• 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

R Source Code

df = 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:")

## [1] "Original dataframe:"

print(df)

##        N    S A   Q
## 1   Jhon 10.0 2 yes
## 2  Hialy  9.5 1  no
## 3 Albert 12.2 2 yes
## 4  James 11.0 4  no
## 5  Delma  8.0 1  no

print("Extract Specific columns:")

## [1] "Extract Specific columns:"

result <- data.frame(df$N,df$S)
print(result)

##     df.N df.S
## 1   Jhon 10.0
## 2  Hialy  9.5
## 3 Albert 12.2
## 4  James 11.0
## 5  Delma  8.0