Hi Carolina, it could be a syntaxis ommition indeed, I see a space that I think it must not be there, between < and the minus - , (probably = is simpler but I use <- too):
> step.forward < - ordistep(rda(main ~ 1, data=second), scope=formula(RDA.all), direction="forward", pstep=1000) > step.forward <- ordistep(rda(main ~ 1, data=second), scope=formula(RDA.all), direction="forward", pstep=1000) Check that, just in case. Hope this helps, Olmo. El Sat, 4 Feb 2012 15:03:08 -0400 carolina monmany <[email protected]> escribió: > Dear all, > > I am running a redundancy analysis in vegan and I am using ordistep to > perform a forward selection of variables in my model. I'm following > Borcard et al. (2011) for this. I got stuck in one of the steps and > couldn't find out why. > > > RDA.all <- rda(main ~ ., data=second) > > RDA.all > Call: rda(formula = main ~ MeanAsp + SDAsp + MenaSlo + SDSlo + Urban + > Treelines + TreeGroups + > SolTress + IntermGrass + TallGrass + Highways + Canals + DistDCA + > MeanTrackDens + SDTrackDens + > MeanMagnetism, data = second) > > Inertia Proportion Rank > Total 0.005999 1.000000 > Constrained 0.005999 1.000000 9 > Unconstrained 0.000000 0.000000 0 > Inertia is variance > Some constraints were aliased because they were collinear (redundant) > > Eigenvalues for constrained axes: > RDA1 RDA2 RDA3 RDA4 RDA5 RDA6 RDA7 > RDA8 RDA9 > 4.421e-03 1.406e-03 8.930e-05 5.354e-05 1.413e-05 8.836e-06 4.612e-06 > 1.324e-06 3.500e-07 > > # And here's the problem, > > > step.forward < - ordistep(rda(main ~ 1, data=second), > scope=formula(RDA.all), direction="forward", pstep=1000) > Error: object 'step.forward' not found > > I hope it's a syntaxis ommition or error. Any clue? > > Thanks a lot, > > Carolina > _______________________________________________ R-sig-ecology mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
