This is a low priority bug that has been around for a while, but I came acr= oss it again while alpha testing 2.8.
The resulting function for splinefun gives incorrect deriv values when x is= less than the smallest x-value used to create the function (at least in on= e circumstance), but does the correct thing for x greater than the largest = x-value. Here is an example: > x <- 1:10 > y <- sin(x) > > splfun <- splinefun(x,y, method=3D'natural') > > # these should be linear (and are) > splfun( seq(0,1, 0.1) ) [1] 0.5682923 0.5956102 0.6229280 0.6502459 0.6775638 0.7048816 0.7321995 [8] 0.7595174 0.7868352 0.8141531 0.8414710 > > # these should all be the same > splfun( seq(0,1, 0.1), deriv=3D1 ) [1] -0.34287807 -0.22582729 -0.12109764 -0.02868912 0.05139826 0.1191645= 1 [7] 0.17460962 0.21773359 0.24853643 0.26701813 0.27317870 > > # these should all be 0 > splfun( seq(0,1, 0.1), deriv=3D2 ) [1] 1.2321135 1.1089022 0.9856908 0.8624795 0.7392681 0.6160568 0.4928454 [8] 0.3696341 0.2464227 0.1232114 0.0000000 > splfun( seq(0,1, 0.1), deriv=3D3 ) [1] -1.232114 -1.232114 -1.232114 -1.232114 -1.232114 -1.232114 -1.232114 [8] -1.232114 -1.232114 -1.232114 -1.232114 > > > # everything works like it should on the right end > splfun( seq(10,11, 0.1) ) [1] -0.5440211 -0.6444546 -0.7448881 -0.8453215 -0.9457550 -1.0461885 [7] -1.1466220 -1.2470554 -1.3474889 -1.4479224 -1.5483559 > splfun( seq(10,11, 0.1), deriv=3D1 ) [1] -1.004335 -1.004335 -1.004335 -1.004335 -1.004335 -1.004335 -1.004335 [8] -1.004335 -1.004335 -1.004335 -1.004335 > splfun( seq(10,11, 0.1), deriv=3D2 ) [1] 0 0 0 0 0 0 0 0 0 0 0 > splfun( seq(10,11, 0.1), deriv=3D3 ) [1] 0 0 0 0 0 0 0 0 0 0 0 > --please do not edit the information below-- Version: platform =3D i386-pc-mingw32 arch =3D i386 os =3D mingw32 system =3D i386, mingw32 status =3D alpha major =3D 2 minor =3D 8.0 year =3D 2008 month =3D 10 day =3D 01 svn rev =3D 46589 language =3D R version.string =3D R version 2.8.0 alpha (2008-10-01 r46589) Windows XP (build 2600) Service Pack 3 Locale: LC_COLLATE=3DEnglish_United States.1252;LC_CTYPE=3DEnglish_United States.12= 52;LC_MONETARY=3DEnglish_United States.1252;LC_NUMERIC=3DC;LC_TIME=3DEnglis= h_United States.1252 Search Path: .GlobalEnv, package:stats, package:graphics, package:grDevices, package:ut= ils, package:datasets, package:methods, Autoloads, package:base -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare [EMAIL PROTECTED] 801.408.8111 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
