Hello, The answer is in one page of the R Wiki (just created to address such a question, by the way): http://wiki.r-project.org/rwiki/doku.php?id=tips:data-manip:calc_on_two_tables
..............................................<°}))><........ ) ) ) ) ) ( ( ( ( ( Prof. Philippe Grosjean ) ) ) ) ) ( ( ( ( ( Numerical Ecology of Aquatic Systems ) ) ) ) ) Mons-Hainaut University, Belgium ( ( ( ( ( .............................................................. Felix Wave wrote: > Hello, > I have got two matrices with different length. The matrices have 3 > columuns. The first two are coordinates. The third is a measurement. > > Now I want to get a subtraction between every single value of the > third column (between matrix1 and matrix2), but only if the two > first coordinates in matrix1 and matrix2 are the same. > > I tried "FUN=?" in aggregate and ave, but I don't know the command > for such a subtraction? > > > Thank's a lot. > Felix > > > --------------- > > The matrixes (examlple): > > 1 0.1 0.0042 > 1 0.2 0.00423 > 1 0.4 0.00467 > 1 0.5 0.00518 > 1 0.6 0.0061 > > > 1 0.1 0.0043 > 1 0.2 0.00442 > 1 0.3 0.00433 > 1 0.4 0.0045 > 1 0.5 0.00524 > 1 0.7 0.006 > > > > My aim: > ------- > 1 0.1 -0.0001 > 1 0.2 -0.00019 > 1 0.4 0.00017 > 1 0.5 -0.00006 > > ______________________________________________ > [email protected] 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. > ______________________________________________ [email protected] 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.
