[R] Looping through a dataframe

[e-mail ma015k3113]

Dear All, I have a dataframe which has a few thousand companies with unique company numbers and names and  each company has data for several years and each year is stored in a separate row.

I want to get a total for the number of years of data for each company. When I loop through the data with the following command  I get a value of ‘1’ rather than a total of the rows for each company

All_companies$count <-0

while All_companies$COMPANY_NAME == All_companies$COMPANY_NAME + 1

+ {All_companies$count=All_companies$count+1}

Can you kindly help me on this?

Ahson
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