However, as I learned today, caching "thousands" of addresses in your database seems to be out of bounds, according to Google documentation.
See discussion in this thread http://groups.google.com/group/Google-Maps-API/browse_thread/thread/7ef981653848a418/25437b271acf43ee?hl=en#25437b271acf43ee On Oct 22, 3:55 pm, boomerbubba <[EMAIL PROTECTED]> wrote: > So long as your site meets the requirements for the free API, and you > are using the geocoded points in your database only for the purpose of > driving that site, my own quite unofficial understanding is that it is > okay with Google for you to geocode your batch and cache the results. > > I wrote that post poorly. I should have said "do not expect to get > decent geocoding for free" unless you comply with the provider's terms > and conditions. I do think Google's geocoder is quite decent, and it > does return precision indicators sufficient to process the data > intelligently. > > However, the same caveats apply. It is still up to you to build your > batch application to actually handle those precision indicators > intelligently, which likely involves some human intervention to deal > with errors and ambiguities that are flagged. In fact, that is one of > the advantages of batch geocoding: It provides an opportunity to do > this scrubbing once, offline. > > On Oct 22, 3:29 pm, JF <[EMAIL PROTECTED]> wrote: > > > > > Yes, the site is freely available to public. > > > On Oct 22, 3:43 pm, boomerbubba <[EMAIL PROTECTED]> wrote: > > > > p.s. If you want to use Google's API to geocode this volume, and your > > > site otherwise qualifies for the free API (freely accessible to the > > > public), then I believe Google does not object to your geocoding your > > > database once and reusing the coordinates at run time. If your site > > > does not qualify for the free API, you also can explore a license for > > > Google Maps Premier. > > > > On Oct 22, 2:36 pm, boomerbubba <[EMAIL PROTECTED]> wrote: > > > > > Much depends on the accuracy you desire. Most of the free geocoders > > > > listed on that page are not worth much in that regard, compared to > > > > professional-level, licensed geocoding software or services. > > > > > As for batchgeocode.com, it uses the Yahoo API's geocoding engine. > > > > Yahoo sends precision flags and sometimes warnings with each address > > > > transaction, but batchgeocode.com discards those important data > > > > elements and just plots Yahoo's best guess. So some addresses will > > > > not be geocoded at all, others will be geocoded at grossly wrong > > > > locations, with nary a warning to the user. > > > > > Yahoo seems to tolerate this use of its geocoding engine -- on its > > > > face an apparent violation of the Yahoo API -- so long as the batch > > > > geocoding is crippled by suppressing the warnings. That way, the > > > > intellectual property and market of providers such as Tele Atlas, > > > > which markets professional-level geocoding services, is fairly well > > > > protected. It's easy to see at least some of the precision warnings > > > > of Yahoo and Google -- by submitting one address at a time -- to a > > > > different third-party site:http://www.gpsvisualizer.com/geocode. If > > > > you want to see everything, you must use the APIs, which impose legal > > > > restrictions on their use. > > > > > But do not expect to get decent geocoding for free. I suggest that > > > > you explore a commercial solution to geocode your batch of 15,000 > > > > locations. A professional geocoding engine will return, along with > > > > the lat/lon coordinates, specific fields denoting the precision and > > > > warn of ambiguities. Then you must set you quality threshhold, decide > > > > on a strategy to fix errors and resolve ambiguities, and design your > > > > own application to comply with whatever business rules you set. > > > > Achieving anything approaching 100 percent accuracy will almost > > > > certainly involve human effort to deal with exceptions. The error > > > > rate will also be a function of how well your input addresses are > > > > validated and standardized in advance. Garbage in, garbage out. > > > > > On Oct 22, 2:14 pm, JF <[EMAIL PROTECTED]> wrote: > > > > > > Thanks for this info! I tried many Geocoders listed > > > > > onhttp://groups.google.com/group/Google-Maps-API/web/resources-non-goog..., > > > > > but none of them seem to work for me. This is for a project located in > > > > > Canada, so already the set of Geocoders that can be used is reduced to > > > > > the ones providing data for Canada. Many links on that page refer to > > > > > Geocoding pages using Yahoo!'s geocoder, but yahoo only allows to use > > > > > its geocoding service if it to use the data in conjuction with Yahoo > > > > > Maps; we want to use Google Maps. geocoder.ibegin.com, which is listed > > > > > on that page, seemed to offer an interesting solution, however it > > > > > could not locate my place properly (right street, but wrong city!). > > > > > > We have a database containing Latitudes and Longitudes for all postal > > > > > codes in Canada, and I can use that. However, full addresses > > > > > geolocalization gives better results, especially for remote places > > > > > where postal codes cover a large area. > > > > > > We have an interface on our Intranet that allows us to enter new > > > > > locations in the database driving our web site. What I would like > > > > > would be to have the possibility to geocode a location when that place > > > > > is saved in our database, and to save the latitude and longitude at > > > > > the same time. It would be easy to do this we Google's geocoder, but I > > > > > am not sure whether this would infringe its terms of use. I would > > > > > really appreciate getting feedback from Google about this. > > > > > > JF > > > > > > On Oct 22, 11:36 am, mapperzUK <[EMAIL PROTECTED]> wrote: > > > > > > > JF as noted by Pamela Fox in the Tutorial -'Using PHP/MySQL with > > > > > > Google Maps' > > > > > > > "Note: This tutorial uses location data that already have latitude > > > > > > and > > > > > > longitude information needed to plot corresponding markers. If > > > > > > you're > > > > > > trying to use your own data that don't yet have that information, > > > > > > use > > > > > > a batch geocoding service to convert the addresses into latitudes/ > > > > > > longitudes. Some sites make the mistake of geocoding addresses each > > > > > > time a page loads, but doing so will result in slower page loads and > > > > > > unnecessary repeat geocodes. It's always better to hardcode the > > > > > > latitude/longitude information when possible. This link contains a > > > > > > good list of > > > > > > geocoders:http://groups.google.com/group/Google-Maps-API/web/resources-non-goog... > > > > > > " > > > > > > >http://code.google.com/support/bin/answer.py?answer=65622 > > > > > > > so if you pre-geocode your 15,000 locations into a database then you > > > > > > will achieve your option 2. > > > > > > > (but never trust a geocoder - Mike > > > > > > Williams)http://markmail.org/message/ryz24bm7n66ew6b5 > > > > > > > Mapperzhttp://mapperz.blogspot.com/ > > > > > > > On Oct 22, 4:17 pm, JF <[EMAIL PROTECTED]> wrote: > > > > > > > > I have the following problem. I am working on a web site backed > > > > > > > by a > > > > > > > database containing around 15 000 locations. These locations can > > > > > > > be > > > > > > > displayed on maps on the web site. On these maps, other > > > > > > > surrounding > > > > > > > locations should also be displayed. In the end, around 50 > > > > > > > locations > > > > > > > could be displayed on a single map with its main point of > > > > > > > interest. So > > > > > > > before displaying the map, around 50 locations will need to be > > > > > > > geocoded in order to position them on the map. The geocoding > > > > > > > requests > > > > > > > would be issued by the server, which seems to be a problem. > > > > > > > Imagine > > > > > > > that 10 people are surfing the site and viewing maps at the same > > > > > > > time, > > > > > > > it would mean that the server would need to geocode 500 locations > > > > > > > in a > > > > > > > short amount of time. This is a problem, since Google's geocoding > > > > > > > servers stop answering when too many request are coming from the > > > > > > > same > > > > > > > location all at once. > > > > > > > > I see two solutions: > > > > > > > > 1) The geocoding should be done on the client side. However, in > > > > > > > most > > > > > > > Google Map examples, the latitudes and longitudes are provided by > > > > > > > the > > > > > > > server. Is there somewhere a good example in which latitudes and > > > > > > > longitudes are fetched by the client just before displaying the > > > > > > > map? > > > > > > > > I see a drawback with this technique though. It does not reduce > > > > > > > the > > > > > > > load on Google's geocoding servers. > > > > > > > > 2) A better technique would be to cache the geocoding data > > > > > > > (latitudes > > > > > > > and longitudes) for the 15 000 locations on the server beforehand. > > > > > > > This appears to me as being much cleaner, and it removes some > > > > > > > burden > > > > > > > from Google's geocoding servers. What is the point of geocoding > > > > > > > the > > > > > > > same locations multiple times anyway? > > > > > > > > However, there seem to be a legal issue with this second > > > > > > > technique. Onhttp://maps.google.com/help/terms_maps.html, one can > > > > > > > read the > > > > > > > following: > > > > > > > > <blockquote>Also, you may not use Google Maps in a manner which > > > > > > > gives > > > > > > > you or any other person access to mass downloads or bulk feeds of > > > > > > > numerical latitude and longitude coordinates.</blockquote> > > > > > > > > This appears to make the second solution illegal, which is really > > > > > > > too > > > > > > > bad. I would like to get a confirmation of this though from Google > > > > > > > staff. > > > > > > > > Cheers! > > > > > > > > JF- Hide quoted text - > > > > > > - Show quoted text -- Hide quoted text - > > > > > - Show quoted text -- Hide quoted text - > > > - Show quoted text -- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. 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