Addendum: The simplified expression removes the division, because 2 * .50 is one, and anything divided by one is itself:
(.50 * (int( 2 * (MoneyValue + .25)))) Bill On Tue, Aug 30, 2011 at 8:31 AM, Bill Downall < [email protected]> wrote: > Oops. The QA department here is going to get fired. There are 2 50 centses > in a dollar, so to use INT, I need to multiple halves into wholes, and then > divide by 2 again. > > (Also had a parenthesis missing in the previous try.) > > You can simplify the math below, but this seems to work, and shows all the > numbers in my twisted logic. > > create table Money (moneyValue CURR, roundGoal CURR) > insert into money values (1.24, 1.0) > insert into money values (1.26, 1.5) > insert into money values (1.49, 1.5) > insert into money values (1.51, 1.5) > insert into money values (1.74, 1.5) > insert into money values (1.76, 2.0) > SELECT MoneyValue, + > (.50 * (int(( 2 * (MoneyValue + .25))) / (2 * .50) )) as > RoundExpression, + > RoundGoal + > FROM Money > MoneyValue RoundExpression RoundGoal > --------------- --------------- --------------- > $1.24 1. $1.00 > $1.26 1. $1.50 > $1.49 1.5 $1.50 > $1.51 1.5 $1.50 > $1.74 1.5 $1.50 > $1.76 2.0 $2.00 > > Bill > > On Tue, Aug 30, 2011 at 8:10 AM, William Stacy > <[email protected]>wrote: > >> Something still wrong there, Bill. plug in 8.55 and you get 8.00. >> >> I think Albert's approach is right and was working on a single rather >> colmplex expression to do the same thing, but then I thought to myself, >> "Self, why are you doing this?" I mean why would anyone want to purposely >> detune data like that? Computers and R:base inherently are accurate to a >> penny withhout any effort on our part... Plus rounding can introduce a >> compounding of errors in certain cases. Envision a carpenter trading in his >> 1/16 inch graduated tape for one with 1/2 inch graduations. >> >> On Tue, Aug 30, 2011 at 3:44 AM, Bill Downall < >> [email protected]> wrote: >> >>> Sorry, Tom, I didn't think it through. Try this: >>> >>> Add .25 to your value, then take the (truncated) integer of the result, >>> and divide that by .50. That gives you the number of 50-cents in your >>> answer, so multiply all that by .50, (or divide by 2). >>> >>> (.50 * (int((currvalue + .25) / .50 )) >>> >>> Bill >>> >>> >>> On Mon, Aug 29, 2011 at 7:40 PM, TOM HART <[email protected]>wrote: >>> >>>> Bill, >>>> I tried 7.46 and it returned 7.4, but I want 7.5 >>>> Tom >>>> >>>> ------------------------------ >>>> *From:* Bill Downall <[email protected]> >>>> *To:* RBASE-L Mailing List <[email protected]> >>>> *Sent:* Mon, August 29, 2011 4:59:29 PM >>>> *Subject:* [RBASE-L] - Re: Rounding >>>> >>>> Tom, >>>> >>>> Multiply by fifty, find the nearest integer, then divide by 50. >>>> >>>> ((nint((50 * currencycolumn)) / 50) >>>> >>>> Bill >>>> >>>> On Mon, Aug 29, 2011 at 5:17 PM, TOM HART <[email protected]>wrote: >>>> >>>>> Is there a way to round currency to the nearest .50, what I want to do >>>>> is round currency the the nearest dollar or .50 >>>>> eg >>>>> >>>>> $1.76 to $2.00 >>>>> $1.74 to $1.50 >>>>> etc >>>>> >>>>> Tom Hart >>>>> >>>>> >>>> >>> >> >> >> -- >> William Stacy, O.D. >> >> Please visit my website by clicking on : >> >> http://www.folsomeye.net >> >> >> >> >
