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" <statqu...@outlook.com> À: "Robin Girard" <robin.gir...@mines-paristech.fr> Cc: rcpp-devel@lists.r-forge.r-project.org Envoyé: 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.gir...@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" < e...@debian.org > À: "Robin Girard" < robin.gir...@mines-paristech.fr > Cc: rcpp-devel@lists.r-forge.r-project.org Envoyé: 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 | Chargé de Recherche | | MINES-ParisTech / Département Energétique et Procédés / PERSEE / Groupe ERSEI | Centre Procédés, Energies Renouvelables et Systèmes Energétiques (PERSEE) | Center for Processes, Renewables Energies and Energy Systems | Renewable Energies & Smartgrids (ERSEI) | | 1 Rue Claude Daunesse - CS 10207 - F-06904 Sophia Antipolis Cedex | Tel: +33.4.93.67.89.64 (~99), Fax: +33.4.93.95.75.35 | e-mail : robin.gir...@mines-paristech.fr | | web page perso http://www.mines-paristech.fr/Services/Annuaire/&?id=8828 | statoverflow : http://stats.stackexchange.com/users/223/robin-girard | web page centre PERSEE : http://www.cep.mines-paristech.fr/ | linkedin : http://www.linkedin.com/profile/view?id=14907272&trk=tab_pro | | Le lien vaut mieux que le bien. | ________________________________________________________ | | CONFIDENTIALITY : This e-mail and any attachments are | confidential and may be privileged. If you are not a | named recipient, please notify the sender immediately and | do not disclose the contents to another person, use it for | any purpose or store or copy the information in any medium. | | CONFIDENTIALITE : Ce message et les éventuelles pièces | attachées sontconfidentiels et peuvent être une | communication protégée. Si vous n'êtes pas dans la liste | des destinataires, veuillez informer l'expéditeur | immédiatement et ne pas ouvrir ni divulguer le contenu | à une tierce personne, ne pas l'utiliser pour quelque | raison que ce soit, ne pas stocker ou copier l'information | qu'il contient sur un quelconque support. | | _______________________________________________ | Rcpp-devel mailing list | Rcpp-devel@lists.r-forge.r-project.org | https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel -- Dirk Eddelbuettel | e...@debian.org | http://dirk.eddelbuettel.com _______________________________________________ Rcpp-devel mailing list Rcpp-devel@lists.r-forge.r-project.org https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel _______________________________________________ Rcpp-devel mailing list Rcpp-devel@lists.r-forge.r-project.org https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
