I have a following dataframe (df) and generated a variable of summation of sales by industry (ksic2). I want to attach this new variable to the original df so that I construct a new dataframe. Any help please?
aggregate(df$sales, by=list(ksic2=df$ksic2), FUN=sum)
structure(list(firmid = structure(c("016090", "002070", "009270",
"007700", "005800", "014990", "001460", "001460", "005800", "014990",
"002070", "016090", "007700", "009270", "001460", "007700", "014990",
"005800", "016090", "002070", "009270", "009270", "002070", "016090",
"007980", "014990", "005800", "007700", "001460", "016090", "007980",
"002070", "001460", "009270", "014990", "007700", "005800", "009270",
"001460", "014990", "020000", "016090", "002070", "007980", "005800",
"007700", "007980", "002070", "007700", "001460"), format.stata = "%-6s"),
year = structure(c(1992, 1992, 1992, 1992, 1992, 1992, 1992,
1993, 1993, 1993, 1993, 1993, 1993, 1993, 1994, 1994, 1994,
1994, 1994, 1994, 1994, 1995, 1995, 1995, 1995, 1995, 1995,
1995, 1995, 1996, 1996, 1996, 1996, 1996, 1996, 1996, 1996,
1997, 1997, 1997, 1997, 1997, 1997, 1997, 1997, 1997, 1998,
1998, 1998, 1998), format.stata = "%9.0g"), ksic2 = structure(c("M) Apparel",
"M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel",
"M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel",
"M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel",
"M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel",
"M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel",
"M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel",
"M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel",
"M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel",
"M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel",
"M) Apparel", "M) Apparel", "M) Apparel", "M) Apparel"), label = "classification", format.stata = "%-62s"),
sales = structure(c(89881001984, 118717997056, 167806992384,
18667999232, 107579998208, 105812000768, 313181995008, 323294003200,
97535000576, 125405003776, 119427997696, 98385002496, 19235999744,
222712004608, 356682989568, 17685999616, 174042005504, 98319998976,
130714001408, 126674001920, 359814987776, 477821992960, 129806000128,
198731005952, 56521998336, 254710005760, 108176998400, 18386999296,
374637002752, 234864001024, 87393001472, 131512999936, 338225004544,
578683994112, 340619984896, 28804999168, 111874998272, 824554029056,
303513010176, 236455002112, 78887002112, 241608998912, 140156993536,
85182996480, 121896001536, 38905999360, 1.37216e+11, 126850998272,
32975998976, 241390993408), format.stata = "%9.0g")), row.names = c(NA,
-50L), class = c("tbl_df", "tbl", "data.frame"))