Hi Boomerbubba! As far as it goes with Yahoo, here is an excerpt of their Terms of use (http://info.yahoo.com/legal/us/yahoo/maps/mapsapi/mapsapi-2141.html):
<blockquote>(viii) store or allow end users to store map imagery, map data or geocoded location information from the Yahoo! Maps APIs for any future use; (ix) use the stand-alone geocoder for any use other than displaying Yahoo! Maps or displaying points on Yahoo! Maps; (x) publish or display, or allow other users to publish or display, any geocoded location information using any Yahoo! Maps APIs; or (xi) use the Yahoo! Maps APIs in a product or service that competes with products or services offered by Yahoo!.</blockquote> You wrote: "But do not expect to get decent geocoding for free." Well, Google's geocoding is quite descent and it returns a precision factor. There is also an easy way to find out if the geocoder is totally off. As I mentioned, we have a database with coordinates for Canadian Postal codes. So it is possible to check the distance between the coordinates for a postal code and the coordinates returned by the geocoder. If that distance is significant, then we cn assume something went wrong with the geocoding. Anyhow, if there is a commercial geocoding solution you can recommand, please let me know, and I will look into it. Cheers and thanks for the feedback! It is much appreciated. JF On Oct 22, 3:36 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 - --~--~---------~--~----~------------~-------~--~----~ 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=en -~----------~----~----~----~------~----~------~--~---
