Please do read the posting guide and the FAQ. E.g. the posting guide says Common posting mistakes: ... Finding a bug in an old version of R that has been fixed in the most recent version.
This was a bug in 1.8.0, but the current version of R is 2.0.0 with 2.0.1 in beta test. We can't fix bugs retrospectively. If you take a look at the `bugs fixed' lists since 1.8.0 you will think you were remiss not to have upgrade a long time ago. On Fri, 5 Nov 2004 [EMAIL PROTECTED] wrote: > Full_Name: Christian Lederer > Version: 1.8.0 > OS: Linux > Submission from: (NULL) (217.229.7.13) > > > R-1.8.0 seems to calculate wrong covariances, when the argument of cov() > is a matrix or a data frame. > The following should produce a matrix of zeroes and NaNs: Actually of zeroes and NAs, and it does in current R. > x <- matrix(c(NA ,NA ,0.9068995 ,NA ,-0.3116229, > -0.06011117 ,0.7310134 ,NA ,1.738362 ,0.6276125, > 0.6615581 ,NA ,NA ,-2.646011 ,-2.126105, > NA ,1.081825 ,NA ,1.253795 ,1.520708, > 0.2822814 ,NA ,NA ,NA ,NA, > 0.03291028 ,NA ,NA ,NA ,NA, > NA ,NA ,NA ,-0.5462126 ,-0.1997394, > NA ,-0.3419413 ,-0.2675226 ,-1.000133 ,-0.1346234, > NA ,NA ,-0.411743 ,1.301612 ,NA, > 0.922197 ,NA ,0.9513522 ,0.2357021 ,NA), > nrow=10, ncol=5) > > c1 <- cov(x, use="pairwise.complete") > > c2 <- matrix(nrow=5, ncol=5) > for (i in 1:5) > { > for (j in 1:5) > { > c2[i,j] <- cov(x[,i], x[,j], use="pairwise.complete") > } > } > > c2-c1 > > Instead, R-1.8.0 produces this result: > > [,1] [,2] [,3] [,4] [,5] > [1,] 0.00000000 -0.03053828 NA -0.0144996353 -0.03485883 > [2,] -0.03053828 -0.01649857 NA 0.0137259383 -0.02960707 > [3,] NA NA -0.1296134 NA NA > [4,] -0.01449964 0.01372594 NA -0.0003152629 0.08717648 > [5,] -0.03485883 -0.02960707 NA 0.0871764791 0.04961190 > > This happens as well under Linux (Suse 9.1) as well as under Windows NT. > > Under 1.9.1 (Linux) and 1.9.0 (Windows) i get the expected matrix of > zeroes and NaNs. > > This example is not very special. Under R-1.8.0 cov produced wrong result > for any random matrix i tried. > > Doesn't this mean, that *any* result obtained under R 1.8.0 is unreliable? >From cov(x, use="pairwise.complete"), yes. But that is a very unusual usage. > By the way, i just recompiled R-1.8.0 from source under Linux and tried > 'make check'. All tests were ok. > Does there exist a more detailed set of tests, which could insure that > at least the most basic R functions work correctly? This is not a `most basic R function'. Look in the test directory in the sources to see that we do have an extensive series of tests. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-devel