Hi The the gcc on Redhat 7.2 with default C compiler configuration setting CFLAGS="-g -O2" produces some worrying differences in output compared to CFLAGS="-g -Wall -pedantic" The following differences were seen in graphical output from running examples: besselI DIFFERENCE in example 4 DIFFERENCE in example 5 (1e+00 becomes 1e-00 in axis label) -- co.intervals DIFFERENCE in example 8 (third y-value in lowess curve different)!!! -- dnbinom DIFFERENCE in example 2 (contour line labels at different locations) -- pbirthday DIFFERENCE in example 1 (1e+00 becomes 1e-00 in axis label) -- persp DIFFERENCE in example 3 (order of drawing surface facets different) ####### Reproduction details Differences were detected in graphics output using the graphicsQC package (see http://www.stat.auckland.ac.nz/~paul/index.html) and ... model.graphics(package="base", device="postscript", format="pbm", model.loc="model", verbose=TRUE) ... to produce output for CFLAGS="-g -O2" and ... test.graphics(package="base", device="postscript", format="pbm", model.loc="model", test.loc="test", verbose=TRUE) ... to produce output for CFLAGS="-g -Wall -pedantic" Paul --please do not edit the information below-- Version: platform = i686-pc-linux-gnu arch = i686 os = linux-gnu system = i686, linux-gnu status = beta major = 1 minor = 8.0 year = 2003 month = 10 day = 07 language = R Search Path: .GlobalEnv, package:methods, package:ctest, package:mva, package:modreg, package:nls, package:ts, package:lattice, package:grid, package:graphicsQC, Autoloads, package:base -- Dr Paul Murrell Department of Statistics The University of Auckland Private Bag 92019 Auckland New Zealand 64 9 3737599 x85392 paul@stat.auckland.ac.nz http://www.stat.auckland.ac.nz/~paul/