“ITEM_GROUP” is passed as an argument to the group_by() function. In below example the row numbers are generated by is “ITEM_GROUP”.
1:n() of the dplyr package also used to generate the row number by group by using group_by() function.
Row number is generated and stored in a column using 1:n() function. Next: Write a R program to get all prime numbers up to a given number (based on the sieve of Eratosthenes). Previous: Write a R program to create a vector which contains 10 random integer values between -50 and +50. Generate Row number of the dataframe by group Contribute your code (and comments) through Disqus. Here, we create a vector of three real numbers. create a vector of real numbers in R vec <- c(1.5, 3.14, 2.71) display the vector print(vec) Output: 1 1.50 3.14 2.71. Note that both integers and real numbers are represented with the numeric type in R. So the resultant dataframe with row number or row index generated and stored in the name of row_number Let’s now create a vector of real numbers. My_basket$row_num % mutate(row_number= 1:n()) Row number is generated and stored in a column using seq.int() function # Generate row number or row index using seq.int() function Generate Row number or Row index to the dataframe using seq.int(): set.seed (12) to obtain a random sample of 10. index <- seqlen (nrow (mtcars)) step 2: sample the index vector. head (mtcars) step 1: create an index vector for the elements/rows. Price = c(100,80,80,90,65,70,60,70,25,60,40,35,50,120), To sample observations (rows) from a data frame or a list, we don’t sample the rows directly but the indices into an object. My_basket = ame(ITEM_GROUP = c("Fruit","Fruit","Fruit","Fruit","Fruit","Vegetable","Vegetable","Vegetable","Vegetable","Dairy","Dairy","Dairy","Dairy","Dairy"), Let’s first create the dataframe # Create dataframe
Sample Function in R with dataset with replacement: As we have set seeds it will give the same set of 5 rows as a sample.