search for: noncommut

Displaying 3 results from an estimated 3 matches for "noncommut".

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2004 Sep 07
2
noncommutative addition: NA+NaN != NaN+NA
Hi guys. Check this out: > NaN +NA [1] NaN > NA + NaN [1] NA I thought "+" was commutative by definition. What's going on? > R.version _ platform powerpc-apple-darwin6.8 arch powerpc os darwin6.8 system powerpc, darwin6.8 status major 1 minor 9.0 year 2004 month 04 day 12 language R > (Both give NA under linux, so it looks
2009 Apr 30
2
NA_real_ <op> NaN -> NA or NaN, should we care?
On Linux when I compile R 2.10.0(devel) (src/main/arithmetic.c in particular) with gcc 3.4.5 using the flags -g -O2 I get noncommutative behavior when adding NA and NaN: > NA_real_ + NaN [1] NaN > NaN + NA_real_ [1] NA If I compile src/main/arithmetic.c without optimization (just -g) then both of those return NA. On Windows, using a precompiled R 2.8.1 from CRAN I get NA for both answers. On Linux, after com...
2003 Nov 04
1
glm offset and interaction bugs (PR#4941)
...<- glm(seedlings ~ vegtype + burn01 + burn02 + offset(log(totalseeds)), data = mydata, family = poisson) summary(out) So is is only partially bogus -- very dangerous for users that are less than hyperalert. The difference between out.barfu and out.ok shows that "+" in formulas is noncommutative, which is very mind bending. The regression in out.ok is o. k. It checks by hand. For a more complete explanation (if more is wanted), including the printout from these summary commands on my machine and the check of out.ok "by hand", see http://www.stat.umn.edu/geyer/5931/mle...