How do I sum the values of a variable by group but RETAIN all records

Question

I have a data frame like this...

Ticker     Date            rec_count

 A            1/1/2019     1

A             2/1/2019     1

A             3/1/2019     1

B             1/1/2019     1

B             2/1/2019     1

B             3/1/2019     1

B             4/1/2019     1

And I basically want to create another variable SUM of the records, so that the new data table would retain all the records in the dataset and include the generated sum field.  Like this...

Ticker     Date            rec_count   sum_recs

 A            1/1/2019     1                 3

A             2/1/2019     1                 3

A             3/1/2019     1                 3

B             1/1/2019     1                 4

B             2/1/2019     1                 4

B             3/1/2019     1                 4

B             4/1/2019     1                 4

I have scoured the internet looking for a solution, but I cannot find one.  Please help!  I am new to R and while to some this may be an elementary question...it is absolutely driving me crazy!

Thanks!

Answer 1

Hey @Kirk, what you can do is, edit your existing dataframe by creating a new column for the variable sum_rec. Something like this:

datframe$sum_rec <- (3,3,3,4,4,4,4)