Dear all
I took the liberty to create a Zenodo Community for CDRs (https://zenodo.org/communities/cdr/)
The main advantage of the Zenodo setup is that it assigns DOIs to he uploaded documents. In that way each CDR can also be cited in an unambiguous way across the Internet.
If it is ok with all the submitters I will (slowly) upload the CDRs to the Zenodo Community with all the appropriate attributions. If you feel that something should not be uploaded or if you think there may be some problems with its uploading, do let me know. For the time being I will not upload the CLOS CDR as there may be some issue with it, although it is probably not that important anymore.
Cheers
MA
--
Marco Antoniotti, Associate Professor tel. +39 - 02 64 48 79 01
DISCo, Università Milano Bicocca U14 2043 http://bimib.disco.unimib.it
Viale Sarca 336
I-20126 Milan (MI) ITALY
Please check: http://cdac2019.lakecomoschool.org
Please check: http://troncopackage.org
Please check: https://www.frontiersin.org/research-topics/7394/network-bioscience
Please note that I am not checking my Spam-box anymore.
Please do not forward this email without asking me first (cum grano salis).
Hello,
I am fooling around IEEE 754 (don't ask why) and I started asking questions to various CL impleentations about the usual corner cases. Take for example the function ACOS.
prompt> (acos 42.0)
#C(0.0 4.430675)
Seems legit, according to CLHS. Now, suppose you do (e.g. in CCL)
CCL prompt> (acos 1D++0) ; 1D++0 is positive infinity
Error: FLOATING-POINT-INVALID-OPERATION detected
performing * on (0.0D0 1D++0)
While executing: CCL::%DOUBLE-FLOAT*-2!, in process Listener(4).
Type cmd-. to abort, cmd-\ for a list of available restarts.
Type :? for other options.
1 >
SBCL prompt> (acos 1D++0) ; No, you can't write that in SBCL, but ber with me.
arithmetic error FLOATING-POINT-INEXACT signalled
[Condition of type FLOATING-POINT-INEXACT]
Restarts:
0: [RETRY] Retry SLIME REPL evaluation request.
1: [*ABORT] Return to SLIME's top level.
2: [REMOVE-FD-HANDLER] Remove #<SB-IMPL::HANDLER INPUT on descriptor 8: #<CLOSURE (LABELS SWANK/SBCL::RUN :IN SWANK/BACKEND:ADD-FD-HANDLER) {12974D1D}>>
3: [ABORT] Exit debugger, returning to top level.
LW prompt> (acos 1D++0)
#C(6.283185307179586D0 1D+-0 #| 1D+-0 is double-float not-a-number |#)
ACOS (and friends) also take complex numbers.
CL-USER 19 > (acos #C( 42 42))
#C(0.785469 -4.7773905)
Things get even more interesting when you pass to ACOS (and friends) a complex number with an infinity RE or IM part.
LW prompt> (acos (complex 42 1D++0))
#C(1D+-0 #| 1D+-0 is double-float not-a-number |# -1D++0 #| -1D++0 is double-float minus-infinity |#)
CCL prompt> (acos (complex 1.0 1D++0))
#C(1.5707963267948966D0 -1D++0)
SCBL prompt> (acos (complex 1.0 1D++0))
arithmetic error FLOATING-POINT-INEXACT signalled
[Condition of type FLOATING-POINT-INEXACT]
Restarts:
0: [RETRY] Retry SLIME REPL evaluation request.
1: [*ABORT] Return to SLIME's top level.
2: [REMOVE-FD-HANDLER] Remove #<SB-IMPL::HANDLER INPUT on descriptor 8: #<CLOSURE (LABELS SWANK/SBCL::RUN :IN SWANK/BACKEND:ADD-FD-HANDLER) {12974D1D}>>
3: [ABORT] Exit debugger, returning to top level.
Now, now, now. We do not like this state of affairs, do we?
So, the question is: what should ACOS (and friends) do in these cases?
What about the LIA ISO/IEC 10967 standards?
All the best
Marco
--
Marco Antoniotti, Associate Professor tel. +39 - 02 64 48 79 01
DISCo, Università Milano Bicocca U14 2043 http://bimib.disco.unimib.it
Viale Sarca 336
I-20126 Milan (MI) ITALY
Please check: http://cdac2019.lakecomoschool.org
Please check: http://troncopackage.org
Please check: https://www.frontiersin.org/research-topics/7394/network-bioscience
Please note that I am not checking my Spam-box anymore.
Please do not forward this email without asking me first (cum grano salis).
