[ale] Decimal Degrees in MySQL

[Greg Freemyer]

Is it a big deal if the last digit of accuracy changes due to rounding issues?

If so, you need to really test all the corner cases.  ie. Float has a
real tendency to take  2.999999 and turn it into 3.000000 or 2.999998.

On Fri, Mar 14, 2008 at 10:17 AM, Christopher Fowler
<cfowler at outpostsentinel.com> wrote:
> I actually used a signed double(10,2)
>
>  It seems to work for now.
>
>
>  On Fri, 2008-03-14 at 10:05 -0400, Chris Kleeschulte wrote:
>  >
>  > I am assuming you mean decimal degrees as it relates to GIS to express
>  > lat and long coordinates. Using a floats can be really really tricky
>  > if resolution of this magnitude is required. Computers cannot
>  > represent certain floats accurately just as humans have problems
>  > computing PI accurately. I would use a string or convert to an integer
>  > where there is not a chance to loose resolution.
>  >
>  >
>  >
>  >
>  > Chris
>
>
> >
>  >
>  >
>  >
>  > On Mar 12, 2008, at 4:11 PM, Christopher Fowler wrote:
>  >
>  > > Can someone tell me the best way to store decimal degrees in MySQL?
>  > >
>  > >
>  > > I want to create columns named ddlat and ddlon.  I'm not sure if I
>  > > should use a float,double, or just a string.
>  > >
>  > >
>  > > Decimal Degrees is formated like this:
>  > >
>  > >
>  > > (-)XXX.XXXXXX
>  > >
>  > >
>  > > Chris
>  > >
>  > >
>  > >
>  > >
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>  >
>
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Greg Freemyer
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