On Fri, Jan 7, 2011 at 8:42 AM, Henrique Dallazuanna <www...@gmail.com> wrote: > Try this: > > rowSums(rowsum(t(m), rep(1:3, c(2, 2, 1)), na.rm = TRUE)) > > > On Fri, Jan 7, 2011 at 2:29 PM, emj83 <stp08...@shef.ac.uk> wrote: > >> >> Hi, >> >> I would like to sum some specific columns in my matrix- for example, my >> matrix looks like this: >> [,1] [,2] [,3] [,4] [,5] >> [1,] 1 NA NA NA NA >> [2,] 2 1 NA 1 NA >> [3,] 3 2 1 2 1 >> [4,] 4 3 2 3 2 >> [5,] NA NA NA 4 3 >> [6,] NA NA NA 5 NA >> >> I would like to find the sum of the first two columns, the second two >> columns and the last column: >> i.e I am left with a vector of c(16, 18, 6).
Can you help me extend this example? I'd like to get (PL_Pos - Costs) for each row in Data1, sum those results for each matching date in Result1, and put the result in a new column in Result1 called 'Daily'. Been messing with this for an hour now. Nothing comes close. Thanks, Mark Result1 = structure(list(TradeDates = structure(c(14249, 14250, 14251, 14252, 14253, 14256, 14257, 14258, 14259, 14260, 14263, 14264 ), class = "Date")), .Names = "TradeDates", row.names = c(NA, 12L), class = "data.frame") Data1 = structure(list(Trade = c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22), PosType = c(1, 1, -1, -1, -1, -1, -1, 1, -1, -1, -1, 1, 1, -1, -1, 1, 1, -1, 1, 1, 1, -1), EnDate = structure(c(14249, 14250, 14251, 14253, 14256, 14256, 14256, 14257, 14258, 14258, 14259, 14259, 14260, 14264, 14264, 14265, 14266, 14267, 14270, 14271, 14273, 14274), class = "Date"), EnTime = c(1406, 1318, 838, 846, 846, 1038, 1102, 918, 838, 950, 1134, 1254, 1110, 846, 1318, 854, 950, 838, 1246, 838, 854, 902), ExDate = structure(c(14249, 14250, 14251, 14253, 14256, 14256, 14256, 14257, 14258, 14258, 14259, 14259, 14260, 14264, 14264, 14265, 14266, 14267, 14270, 14271, 14273, 14274 ), class = "Date"), ExTime = c(1515, 1515, 1030, 942, 1030, 1046, 1110, 1515, 942, 1030, 1142, 1515, 1515, 1030, 1326, 1515, 1515, 1030, 1515, 1515, 1515, 1022), PL_Pos = c(133.5, -41.5, 171, 483.5, 333.5, -29, -54, -291.5, 596, -141.5, -54, 558.5, 533.5, 521, -41.5, 883.5, 358.5, -979, -191.5, 196, -791.5, 446), Costs = c(29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29 ), PL = c(104.5, -70.5, 142, 454.5, 304.5, -58, -83, -320.5, 567, -170.5, -83, 529.5, 504.5, 492, -70.5, 854.5, 329.5, -1008, -220.5, 167, -820.5, 417)), .Names = c("Trade", "PosType", "EnDate", "EnTime", "ExDate", "ExTime", "PL_Pos", "Costs", "PL" ), row.names = c(NA, 22L), class = "data.frame") Result1 Data1 ______________________________________________ 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.