Hi,
Th String maths routines (SDIV, SMULT etc) that Martin alludes to at the bottom of his post are very effective, but do require code changes to all the calcuations in the program. You can achieve the same effect in Universe by putting $OPTIONS STRING.MATH at the top of the program. However, there may be other reasons for getting rounding errors. For example, if you have a an invoice for a number of items and you wish to calculate the tax on that invoice, you can do this one of two ways. You can calculate and round the tax on each item and then add up the individual tax amounts. Or you can add up the value of the items and calculate and round the tax on the total value. The two methods can give different figures. I know most people in the list will be familiar with that scenario but sometimes it is worth making sure that the obvious issues are covered before looking for something more unusual. cheers, asvin > > The problem here is that, just as there are numbers that cannot be > represented accurately in decimal such as 1/3, there are numbers that cannot > be represented accurately in the binary notiation used by the computer. As > an easy example, the number 0.2 cannot be represented accurately and ends up > as something like 0.20000000000000001 as a close approximation. Because IEEE > floating point has a limited number of bits to store the matissa part of the > value, the whole thing scales with bigger numbers. Essentially, a number > cannot have lots of significant figures, wherever they may be in relation to > the decimal point. > > If you add up a large number of figures with these rounding errors they may > accumulate to something significant. Even worse, if you decide to do decimal > scaling with a simple multiply instead of an MD conversion code, the > inaccuracies get scaled too. > > This problem is not unique to UniVerse. It is a well known probelm of > floating point numbers in computer systems. The usual fix in the multivalue > world is to scale numbers (dollars to cents, for example) so that all our > numbers are integers. UV also provides a set of character string arithmetic > functions if you really want to get clever. > > > Martin Phillips > Ladybridge Systems Ltd > 17b Coldstream Lane, Hardingstone, Northampton, NN4 6DB > +44-(0)1604-709200 > ------- > u2-users mailing list > u2-users@listserver.u2ug.org > To unsubscribe please visit http://listserver.u2ug.org/ ************************************************************ HSBC Bank plc may be solicited in the course of its placement efforts for a new issue, by investment clients of the firm for whom the Bank as a firm already provides other services. It may equally decide to allocate to its own proprietary book or with an associate of HSBC Group. This represents a potential conflict of interest. HSBC Bank plc has internal arrangements designed to ensure that the firm would give unbiased and full advice to the corporate finance client about the valuation and pricing of the offering as well as internal systems, controls and procedures to identify and manage conflicts of interest. HSBC Bank plc Registered Office: 8 Canada Square, London E14 5HQ, United Kingdom Registered in England - Number 14259 Authorised and regulated by the Financial Services Authority. ************************************************************ ----------------------------------------- SAVE PAPER - THINK BEFORE YOU PRINT! This transmission has been issued by a member of the HSBC Group "HSBC" for the information of the addressee only and should not be reproduced and/or distributed to any other person. Each page attached hereto must be read in conjunction with any disclaimer which forms part of it. Unless otherwise stated, this transmission is neither an offer nor the solicitation of an offer to sell or purchase any investment. Its contents are based on information obtained from sources believed to be reliable but HSBC makes no representation and accepts no responsibility or liability as to its completeness or accuracy. ------- u2-users mailing list u2-users@listserver.u2ug.org To unsubscribe please visit http://listserver.u2ug.org/
