How to remove values in a column based on other column values equaling the column values above it?-CodePudding

I am currently coding in R and merged two dataframes together so I could include all the information together but I don't want the one column "Cost" to be duplicated multiple times (it was due to the unique values of the last 3 columns). I want it to include the cost 100 only in the first column and then for every other instance where the columns "State", "Market", "Date", and "Cost" are the same as above. I attached what the dataframe looks like and what I want it to be changed to. Thank you!

What it currently looks like

What it should look like

CodePudding user response：

Please use index like in this example:

name_of_your_dataset[nrow_init:nrow_fin, ncol] <- NA

In your case, assuming the name of your dataset as 'data'

data[2:4,4]<- NA

Just leave a positive feedback and if I was useful, just vote this answer up.

CodePudding user response：

Here is a solution using duplicated with your dataframe (df)

     State  Market    Date Cost    Word format               Type
1    AZ Phoenix 10-20-2020  100   HELLO     AM     Sports related
2    AZ Phoenix 10-21-2020   NA GOODBYE     PM Non Sports related
3    AZ Phoenix 10-22-2020   NA     YES     FM            Country
4    AZ Phoenix 10-23-2020   NA    NONE     CM               Rock

Set duplicates to NA

df$Cost[duplicated(df$Cost)] <- NA

Output:

  State  Market       Date Cost    Word format               Type
1    AZ Phoenix 10-20-2020  100   HELLO     AM     Sports related
2    AZ Phoenix 10-21-2020   NA GOODBYE     PM Non Sports related
3    AZ Phoenix 10-22-2020   NA     YES     FM            Country
4    AZ Phoenix 10-23-2020   NA    NONE     CM               Rock