Hi,

I want to assign the encoding points to the google map control in c#.net.
Please send me any sample code for that.







On Fri, Apr 24, 2009 at 7:20 PM, mark mcclure <[email protected]> wrote:

>
> On Apr 23, 10:55 am, Wally <[email protected]> wrote:
>
> > If speed & accuracy are important, look at:
> >  www.polyarc.us/pack
> >  www.polyarc.us/packer.js
>
> It really depends on when you need the speed.  In my
> experiments, packer encodes lines faster than the polyline
> encoder *but* the performance of the map after encoding is
> much better using the polyline encoder.
>
> Here's an example
> Encode:
>
> http://facstaff.unca.edu/mcmcclur/GoogleMaps/EncodePolyline/EncodeAndPack/BritishCoastEncode.html
> Packer:
>
> http://facstaff.unca.edu/mcmcclur/GoogleMaps/EncodePolyline/EncodeAndPack/BritishCoastPack.html
>
> Both of these map display the exact same data - an outline of
> the British coatline using about 50,000 points.  Both of them
> are encoded "on the fly" to give you a sense of encoding
> times.  Packer encodes in 12-15 seconds while the polyline
> encoder encodes in 20-25 seconds.  Indeed, packer is faster at
> encoding.  Now hit the zoom button once.  The polyline encoder
> version changes levels in well under a second.  The packer
> version changes levels in about 5 seconds. These tests were
> performed on my MacBook Pro Laptop running Firefox at 2.16 GHz.
>
> It seems to me that rendering speed after encoding is much more
> important than encoding speed, particularly when you have the
> option to pre-encode.  The real way to improve encoding speed
> is to implement the encoding algorithm in a compiled language,
> like C.  Then the encoding will run about 1000 times faster and
> this issue is moot.  I wrote the polyline encoder in Javascript
> mainly because I knew that everyone in this group would likely
> be able to read and understand Javascript.  Andrew contacted me
> and told me about some newer ports and I'll add those to the
> polyline encoding page.
>
> > It uses integer arithmetic for speed.  It eliminates Lat/Lon
> > projection bias for accuracy.  It has no function calls in the
> > main loop.  It converges quickly with multiple pivots in the
> > same pass.  It compensates for a Douglas-Peucker algorithm
> > deficiency (D-P was designed for polylines not for polygons).
>
> I don't get this.  (1) In compiled languages at least, I expect
> floating point arithmetic to be the fastest available.  Is
> there something about Javascript that makes integer arithmetic
> faster?  (2)  What's this Lat/Lng bias?  The API expects Lat/Lngs.
> (3) Douglas-Peucker works fine with polygons, as the example
> provided here shows.
>
> Mark McClure
>
> >
>

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