Question about checks for min and max values

[Henry Melancon]

Nancy,

Thanks for the information.  Teach anytime you feel like it.  I will listen.  It is amazing what you learn when you simple listen......

Henry


> -----Original Message-----
> From: Nancy Palmquist [mailto:nlp at vss3.com]
> Sent: Friday, July 22, 2005 12:10 PM
> To: Henry Melancon
> Cc: filepro-list at lists.celestial.com
> Subject: Re: Question about checks for min and max values
> 
> Henry Melancon wrote:
> > So is this Filepro behavior normal or is this a bug?  How do other data
> base programs handle a situation like this?  I do not like the fact that a
> "blank" and zero are treated equal in some cases.
> >
> 
> I would say that it is as expected - mostly.
> 
> It can be confusing, I know.
> 
> Here are basically the rules I use:
> 
> 1) always compare like types -
> 
> aa eq ab where aa(8,.2) and ab(8,.2)  - like that
> 
> it is not the same type when you do the following:
> 
> aa eq "2.5"
> 
> filepro has to convert the 2.5 to a type of it's choosing (likely to be
> the same as aa, but this ascii to binary convertion can sometimes give
> unpredicible results, where it might not test true or false when it
> looks like it should.
> 
> Also:
> 
> ab(8,*)="2.5" will never test equal to aa(8,.2)="2.5"
> 
> aa ne ab  - this will never be true because you are comparing:
> "2.5     " eq "    2.50"
> 
> These will not ever work correctly.
> 
> 
> 3)  aa=aa+"0" will change "" to "0" -
> 
> When you are keeping a total, and instead of increasing and reducing the
> number, for some reason you reset it to zero, many programmers will just
> blank it.  These will values, "" and "0" will be treated as the same for
> calculations and most purposes.
> 
> 4)  In a calulation, precision and accuracy can affect the outcome.
> 
> Precision refers to how many decimal places are given in the number.
> 
> If I have 1 1/2 apples, and represent that with 1.50000 - I am
> indicating how well I measured the half by giving the additional
> precision.  I would find that hard to justify when just cutting an apple
> in half.  I would have to use much better measurement tools to provide a
> measurement to 100,000ths.
> 
> Accuracy refers to the number of places that provide actual data.  In
> our apple case, the 1.5 would indicate the correct accuracy for our
> number not 1.50000.
> 
> For calculations, it may be necessary to add precision to provide places
> for rounding but the final answer should be represented only to the
> accuracy of the least precise value.
> 
> (Sorry - I regressed back to my teaching days.  Please forgive me.)
> 
> DATE ASIDE:
> 
> I have had issue with dates stored with dashes instead of slashes
> testing and indexing true.  My solution is simple, on any date that the
> end user can enter, I add this type of wlf for that date.  Then they can
> type what they want - I always get what I want.
> 
> @wlf12	'12 is (8,mdy/)
> 	if 12 ne ""
> 	then: 	12=12+"0";display
> 	then: end
> 
> This will change the date to the slash format very easily.
> 
> 
> 
> Nancy
> 
> --
> Nancy Palmquist 		MOS & filePro Training Available
> Virtual Software Systems	Web Based Training and Consulting
> PHONE: (412) 835-9417		   Web site:  http://www.vss3.com