On Nov 17, 4:03 pm, Susi <[email protected]> wrote: > I am using the polygons from US Census Bureau. > Is that Outdated?
The USPS make changes to their zipcodes on a regular basis. The data from the US Census Bureau is from the year 2000, and it is not actual zipcodes but ZCTAs, which is something different: http://www.census.gov/geo/ZCTA/zcta.html > Where I can get the accurate one? I told you that in my last post. -- Marcelo - http://maps.forum.nu -- > Once again thanks for help.. :) > > On Nov 17, 1:48 pm, Marcelo <[email protected]> wrote: > > > Making tiles takes time. > > D-P is not going to speed it up very much at it will lower the quality > > of your polygons. > > I am also creating zipcode tiles for a client, and to give you an > > example, at zoom 13 the state of Colorado alone takes about 1 hour. > > This is using USNaviguide's up to date > > polygons:http://maps.huge.info/zip.htm > > > If you're using the (outdated) "generalized polygons" from the US > > Census Bureau, the have already applied D-P to those. > > > -- > > Marcelo -http://maps.forum.nu > > -- > > > On Nov 17, 9:34 am, Susi <[email protected]> wrote: > > > > Hi > > > Yeah It is for Custom tiles. I will explain the whole process. > > > I am creating tiles image using GD and I have lat/lon for each zip in > > > US. > > > I am creating imgaes for some zoom level and save these images in my > > > server. Also for a perticular > > > reason I have to update these images onces in a month. Problem is that > > > Its taking time for creating the images. > > > For some lower zoom level, I thought of applying Douglas - Peucker > > > algorithm to reduce the number of the points. > > > so that images can created much faster, I guess. > > > > On Nov 17, 1:15 pm, Marcelo <[email protected]> wrote: > > > > > If you're using custom tiles, (as indicated in your other thread), you > > > > don't really need to reduce the number of points. > > > > If you're using encoded polylines instead, here is the page that > > > > Andrew was referring > > > > to:http://facstaff.unca.edu/mcmcclur/GoogleMaps/EncodePolyline/ > > > > > -- > > > > Marcelo -http://maps.forum.nu > > > > -- > > > > > On Nov 17, 8:01 am, Susi <[email protected]> wrote: > > > > > > Hi > > > > > > How can I reduce number of points displayed on the Map in each Zoom > > > > > level, but same time want to retain the fedility of the shape. > > > > > I have gone through the Douglas - Peucker algorithm to reduce the > > > > > number of the polygons. But we need to provide the tolerance as > > > > > argument. > > > > > How can we calculate the tolerance for each zoom level? Are there any > > > > > equation to calculate the tolerance for each zoom level? Or Is it just > > > > > a constant value? -- You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-maps-api?hl=.
