Actually that's not a big trick
date.getFractionalTimestamp() returns date.m_dt which is a double. The
substraction on double is the "usual one" and
date_end.getFractionalTimestamp()-date_begin.getFractionalTimestamp()
gives a positive number if and only if date_end>date_begin.
My only regret is that it gives longer code line and less ease of reading.
But I clearly understand that it's a matter of convention and if other have
integrated this convention this cannot be changed now, otherwise it will
become a bug for them...
at the end a "bug" is only a missinterpretation of something somewhere ? :)
lots of .getFractionalTimestamp() everywhere for me ...
R.
----- Mail original -----
De: "stat quant" <statquant at outlook.com>
?: "Robin Girard" <robin.girard at mines-paristech.fr>
Cc: rcpp-devel at lists.r-forge.r-project.org
Envoy?: Dimanche 31 Mars 2013 11:32:08
Objet: Re: [Rcpp-devel] Datetime substraction bug ?
Thanks a lot for reporting this I would surely have been caught (may be I
am I'll go through code I wrote using this) by this bug.
Posting your workaround would not hurt I think...
Thanks and cheers
2013/3/30 Robin Girard < robin.girard at mines-paristech.fr >
Thanks you're right I already wrote it myself with getFractional...
and indeed that's not really what we should call a "bug" but it took me a
while to understand that
if date1-date2>0 then date1<date2 ;)
R.
----- Mail original -----
De: "Dirk Eddelbuettel" < edd at debian.org >
?: "Robin Girard" < robin.girard at mines-paristech.fr >
Cc: rcpp-devel at lists.r-forge.r-project.org
Envoy?: Samedi 30 Mars 2013 00:44:08
Objet: Re: [Rcpp-devel] Datetime substraction bug ?
On 29 March 2013 at 23:37, Robin Girard wrote:
| Hi List
|
| why is it that we have in the Datetime definition
| (here
http://dirk.eddelbuettel.com/code/rcpp/html/Date_8cpp_source.html#l00271 )
|
| double operator-(const Datetime& d1, const Datetime& d2) { return
d2.m_dt - d1.m_dt; }
| bool operator<(const Datetime &d1, const Datetime& d2) { return d1.m_dt
< d2.m_dt; }
|
| I feel there is a contradiction
| substraction shoulb be d1.m_dt - d2.m_dt; no ?
It's been a while since I wrote that and I think I followed the difftime()
convention in R. Or maybe not. To me d1 comes before d2 in the way the
arguments are given, so d2 is larger and I want to subtract d1 from d2.
In any event, if it bugs you greatly you are always free to write your own
function. ;-)
Dirk
|
| Robin
|
| Dr. Girard Robin
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