为ar数据框分配一个列名

Question

Please pardon my ignorance ,Since i am beginner in R

In R i am transposing a dataframe (certain rows to columns) and saving the result back to a data frame which is exactly what i need . But the column name for the 1st column is missing which i need to join it with other data frames .

Data frame result and function used

dish_pair<-as.data.frame.matrix(xtabs(count~primary_id+subcategory_name, dishes))

output

But How can i get the 1st column name as primary_id
which are holding row values 50792 ,50793

(I just need the 1st column name value as primary_id ,renaming data frame values are correct)

Answer 1

The first column on the picture is just the row names. You need to add it to the data frame and give the column a name:

 dish_pair <- data.frame(primary_id=rownames(dish_pair), dish_pair)