[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
log2 replacement
From: |
John W. Eaton |
Subject: |
log2 replacement |
Date: |
Tue, 29 Apr 2008 14:19:17 -0400 |
On 25-Apr-2008, Jaroslav Hajek wrote:
| hello,
|
| please consider the attached changeset.
| The current log2 behaviour with two outputs (`[f, e] = log2(x)') is
| inconsistent with Matlab in a number of cases, (x = Inf, x = NaN) or
| just plain wrong (x = realmax). Also, on most of the systems the
| 2-output version can be mapped directly to frexp (a C89 function),
| which is probably what Matlab also does. I have implemented the
| single-output log2 as a mapper for octave_value (aka log, log10 etc),
| and the two-output version as an overload in liboctave/lo-mappers.cc
| with a replacement if frexp is not detected. The DEFUN is in
| DLD-FUNCTIONS rather than mappers.cc directly, because it is not a
| simple mapper and thus did not seem to fit "aesthetically" to
| mappers.cc (but that can be easily changed).
|
| Note that the 2-output version is also extended beyond matlab
| behaviour for complex input - while matlab ignores the imaginary part
| (with a warning), this new version gives the result with f complex,
| satisfying 1/2 <= abs(f) < 1, e integer - because it makes good sense
| also for complex numbers.
With this patch, I see the following error with make check:
src/DLD-FUNCTIONS/hex2num.cc ........................... PASS 2/2
src/DLD-FUNCTIONS/log2.cc .............................. PASS 0/2 FAIL 2
src/DLD-FUNCTIONS/lookup.cc ............................ PASS 16/16
src/DLD-FUNCTIONS/lsode.cc ............................. PASS 5/5
src/DLD-FUNCTIONS/luinc.cc ............................. PASS 2/2
src/DLD-FUNCTIONS/matrix_type.cc ....................... PASS 51/51
src/DLD-FUNCTIONS/max.cc ............................... PASS 12/12
src/DLD-FUNCTIONS/qr.cc ................................ PASS 21/21
src/DLD-FUNCTIONS/quad.cc .............................. PASS 6/6
src/DLD-FUNCTIONS/rand.cc .............................. PASS 57/57
src/DLD-FUNCTIONS/regexp.cc ............................ PASS 81/81
src/DLD-FUNCTIONS/time.cc .............................. PASS 13/13
src/DLD-FUNCTIONS/tsearch.cc ........................... PASS 6/6
src/data.cc ............................................ PASS 98/98
src/mappers.cc ......................................... PASS 7/7
src/ov-fcn-handle.cc ...................................panic: Segmentation
fault -- stopping myself...
make[2]: *** [check] Segmentation fault
make[2]: Leaving directory `/scratch/jwe/build/octave-tmp/test'
make[1]: *** [check] Error 2
make[1]: Leaving directory `/scratch/jwe/build/octave-tmp'
make: *** [check] Error 2
Does it work properly for you?
jwe