On 10 May 2011, at 19:20, Dave Walker wrote: > Dilwyn, > > Writing such routines from scratch is likely to be a non-trivial task! >
I would agree with this. > The c68 library has a whole set of support routines written in assembler for > this purpose that conform to the IEEE standard for Double Precision floating > point. I suspect it would not be that hard to put some Basic keywords at > the front-end of them to make them accessible from SuperBasic. They have > the advantage that they have been put through a formal test suite to check > that they give the correct answers which might be important? > > If you could give an indication of how you expect to use them then I could > have a quick look to see if I think the c68 routines could be adapted to > that purpose. It would be nice to know what operations you want to carry > out if it is more than simply arithmetic operations. Possibly important is > how you expect to load up and extract the values without losing precision. > > Of course if you wanted to use them from C then they are ready to go - you > just need to use the 'long double' data type. > I would think it MUCH easier to use C68 to do the arithmetic. A small program could be started by EW from a BASIC program. > Dave Walker > > Tel: +44 (0)1707 652791 > Mob: +44 (0)7999 218953 > Web: http://www.itimpi.com > Skype: itimpi > >> -----Original Message----- >> From: ql-users-boun...@lists.q-v-d.com [mailto:ql-users- >> boun...@lists.q-v-d.com] On Behalf Of Dilwyn Jones >> Sent: 10 May 2011 18:14 >> To: ql-users@lists.q-v-d.com >> Subject: [Ql-Users] Arithmetic precision >> >> Does anyone know of any routines for the QL which can handle double >> precision floating point maths? >> >> When asked, all I could think of was Helmut AInger's math toolkit, but >> I haven't looked at it yet. >> >> Alternatively, if anyone knows how to write such a routine (a BASIC >> demo would do) or has a sample listing showing how to achieve this I'd >> be very grateful. >> >> At this stage, accuracy is more important than speed. >> >> Dilwyn Jones >> >> George _______________________________________________ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
