axis() produces junk on DEC alpha (PR#274)

[maechler@stat.math.ethz.ch]

>>>>> On Mon, 13 Sep 1999 17:41:07 +0200 (MET DST), ripley@stats.ox.ac.uk (Brian D. Ripley) said:

    >> Date: Mon, 13 Sep 1999 10:57:23 +0200 (MET DST)
    >> From: Albrecht Gebhardt <albrecht.gebhardt@uni-klu.ac.at>
    >>
    >> On Mon, 13 Sep 1999, Prof Brian D Ripley wrote:

    BDR> [...]

    BDR> I'm puzzled.  Are you saying -Inf passes R_FINITE and passes
    BDR> ISNAN? (Wow!, if so.) In any case, let us try and fix the macros
    BDR> (which crop up in many places) not two instances.
    BDR>
    >> NaN passed R_FINITE (see above). Then it gets multiplied by some
    >> values and serves as tickmark length.
    >>
    >> >
    >> > There are too many options in Arith.h to guess: can you please tell us
    >> > what path is being taken (HAVE_FINITE, IEEE_754, FINITE_BROKEN, ...).

    >> in src/include/Rconfig.h:
    >> /* Floating Point Arithmetic */
    >> /* #undef HAVE_MATHERR */               /* System V */
    >> #define HAVE_ISNAN 1            /* IEEE Arith indicator */
    >> #define HAVE_FINITE 1
    >>
    >> /* #undef HAVE_FLOATINGPOINT_H */
    >> /* #undef HAVE_FPU_CONTROL_H */
    >> /* #undef HAVE_IEEEFP_H */              /* "-Wall" */
    >> /* #undef HAVE_IEEE754_H */             /* Linux */
    >>
    >> #ifdef HAVE_ISNAN
    >> #ifdef HAVE_FINITE
    >> #define IEEE_754
    >> #endif
    >> #endif
    >>
    >> and some lines below:
    >> /* Bug Workarounds */
    >> /* #undef HAVE_OSF_SPRINTF_BUG */
    >> #define CALLOC_BROKEN 1
    >> #define FINITE_BROKEN 1
    >> #define LOG_BROKEN 1
    >>
    >>
    >> >
    >> > I believe this can all be tested from interpreted R code. I believe you
    >> > should get  (is.na(c(2.0, Inf, -Inf, NaN, NA)) etc)
    >> >            2.0 Inf -Inf NaN NA
    >> > is.na       F   F    F   T   T
    >> > is.finite   T   F    F   F   F
    >> > is.infinite F   T    T   F   F
    >> > is.nan      F   F    F   T   F
    >>
    >>
    >> > is.na(c(2.0, Inf, -Inf, NaN, NA))
    >> [1] FALSE FALSE FALSE  TRUE  TRUE
    >> > is.finite(c(2.0, Inf, -Inf, NaN, NA))
    >> [1] TRUE TRUE TRUE TRUE TRUE
    >> > is.infinite(c(2.0, Inf, -Inf, NaN, NA))
    >> [1] FALSE FALSE FALSE FALSE FALSE
    >> > is.nan(c(2.0, Inf, -Inf, NaN, NA))
    >> [1] FALSE FALSE FALSE  TRUE FALSE
    >>
    >> Seems that everything is R_FINITE!

    BDR> [...]

    BDR> OK, so I think you are at the line

    BDR> #   define R_FINITE(x)          ((x) != R_NaReal)

    BDR> in Arith.h, and that is clearly inadequate (although it should have
    BDR> caught the NA, I think). Can you please try replacing that line by

    BDR> static int R_FINITE(double x) {
    BDR> return !isnan(x) & (x != R_PosInf) & (x != R_NegInf);
    BDR> }

    BDR> and try those tests again.

    BDR> (Kurt: looks like finite can be broken in more ways than one. I suggest
    BDR> return(finite(1./0.) & finite(0./0.) & finite(-1./0.)) in aclocal.m4,

shouldn't this be "|" instead of "&"   [broken if either is finite] ?

    BDR> and if FINITE_BROKEN going directly to some function like the
    BDR> above, and not trying to be efficient, just right!)
{weak voice in the background:
 it may be worth tyring to be both right and efficient ..
 but I agree that "right" is much more important!
}

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