Alfredo Alessandrini wrote: > I've a matrix like this: > > 1985 1.38 1.27 1.84 2.10 0.59 3.47 > 1986 1.05 1.13 1.21 1.54 0.21 2.14 > 1987 1.33 1.21 1.77 1.44 0.27 2.85 > 1988 1.86 1.06 2.33 2.14 0.55 1.40 > 1989 2.10 0.65 2.74 2.43 1.19 1.45 > 1990 1.55 0.00 1.59 1.94 0.99 2.14 > 1991 0.92 0.72 0.50 1.29 0.54 1.22 > 1992 2.15 1.28 1.23 2.26 1.22 3.17 > 1993 1.50 0.87 1.68 1.97 0.83 2.55 > 1994 0.69 0.00 0.76 1.89 0.60 0.87 > 1995 1.13 1.04 1.19 1.52 1.13 1.78 > > Can I utilise a cumsum inverse? from 1995 to 1985? > i guess you mean columnwise cumsums computed starting from the bottom up? then this should do (given that your data is in matrix m, and years are row labels, not data):
rc = nrow(m) cumsums = apply(m[rc:1,], 2, cumsum)[rc:1,] vQ ______________________________________________ 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.
