Dear R users, Can someone help me on this? I would like to find the sum of the Rain if the Month appears more than once. For example in row 3 and 4, October appear more than once, so I want to find the sum of the two rows and replace it so that the Month just appear once. It some sort of merge but by finding the sum for the third column. This is my data:
structure(list(Year = c(1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1972L, 1972L, 1972L, 1972L, 1972L, 1972L, 1973L, 1973L, 1973L, 1973L, 1973L, 1973L, 1973L, 1973L, 1973L, 1973L, 1974L, 1974L, 1974L, 1974L, 1974L, 1974L, 1974L, 1974L, 1974L, 1975L, 1975L, 1975L, 1975L, 1975L, 1975L, 1975L, 1976L, 1976L, 1976L, 1976L, 1976L, 1976L, 1976L, 1976L, 1976L), Month = c(3L, 6L, 10L, 10L, 11L, 11L, 11L, 11L, 12L, 2L, 9L, 12L, 12L, 12L, 12L, 3L, 9L, 10L, 11L, 11L, 11L, 11L, 12L, 12L, 12L, 8L, 9L, 11L, 11L, 11L, 11L, 11L, 12L, 12L, 1L, 2L, 4L, 10L, 11L, 12L, 12L, 10L, 11L, 11L, 11L, 11L, 11L, 11L, 11L, 11L), Rain = c(196, 88.8, 96, 70.6, 104.9, 80, 102.8, 161.5, 123.4, 70.8, 99, 77.7, 130.8, 134.1, 86.3, 213.3, 169.9, 89.4, 78.7, 81.5, 100.3, 107.1, 93.2, 83.8, 253.2, 75.4, 134.5, 84.5, 82.5, 82.5, 119.5, 119.5, 134.5, 83.5, 372.5, 79.5, 112, 80.5, 129.5, 120.5, 126, 73, 93.5, 86.5, 140.5, 76, 180.5, 75, 130.5, 130.5)), .Names = c("Year", "Month", "Rain"), row.names = c(NA, 50L), class = "data.frame") Thank you so much for the help. Arshad [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.