On Tue, May 18, 2010 at 6:32 PM, baptiste auguie <baptiste.aug...@googlemail.com> wrote: > Dear all, > > I got a couple of warnings using panel.levelplot.raster, > > In panel.levelplot.raster(..., interpolate = TRUE) : > 'y' values are not equispaced; output will be wrong > > although I was quite sure my data were equally spaced (indeed, I > created them with seq()). A closer look at the source code reveals > that the function tests for exact uniformity in grid spacing, > > if (length(unique(diff(uy))) != 1) > warning("'x' values are not equispaced; output will be wrong")
Maybe a better test would be isTRUE(all.equal(diff(range(diff(ux))), 0)) I'll try that out for the next release. -Deepayan > > The following dummy example would suggest that a strict equality is > not always suitable, > > x <- seq(0, 50, length=100) > ux <- sort(unique(x[!is.na(x)])) > length(unique(diff(ux))) > # 8 > sd(unique(diff(ux))) > # 2.462951e-15 > > Suggestions / comments are welcome. > > Best regards, > > baptiste > > > sessionInfo() > R version 2.11.0 RC (2010-04-16 r51754) > i386-apple-darwin9.8.0 > > locale: > [1] en_GB.UTF-8/en_GB.UTF-8/C/C/en_GB.UTF-8/en_GB.UTF-8 > > attached base packages: > [1] stats graphics grDevices utils datasets methods base > > other attached packages: > [1] lattice_0.18-5 > > loaded via a namespace (and not attached): > [1] grid_2.11.0 tools_2.11.0 > > > > -- > ____________________ > > Baptiste Auguié > > Departamento de Química Física, > Universidade de Vigo, > Campus Universitario, 36310, Vigo, Spain > > tel: +34 9868 18617 > http://webs.uvigo.es/coloides > ____________________ > > ______________________________________________ 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.