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I need to create a column with unique ID, basically add the row number as an own column. My current data frame looks like this:
V1 V2 1 23 45 2 45 45 3 56 67 How to make it look like this:
V1 V2 V3 1 23 45 2 45 45 3 56 67 ?
Many thanks
467
To Generate Row number to the dataframe in R we will be using seq.int() function. Seq.int() function along with nrow() is used to generate row number to the dataframe in R. We can also use row_number() function to generate row index.
How do I add a column to a DataFrame in R? To add a new column to a dataframe in R you can use the $-operator. For example, to add the column “NewColumn”, you can do like this: dataf$NewColumn <- Values . Now, this will effectively add your new variable to your dataset.
Two tidyverse alternatives (using sgibb's example data):
tibble::rowid_to_column(d, "ID") which gives:
ID V1 V2 1 1 23 45 2 2 45 45 3 3 56 67
Or:
dplyr::mutate(d, ID = row_number()) which gives:
V1 V2 ID 1 23 45 1 2 45 45 2 3 56 67 3
As you can see, the rowid_to_column-function adds the new column in front of the other ones while the mutate&row_number()-combo adds the new column after the others.
And another base R alternative:
d$ID <- seq_along(d[,1]) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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