Yes, infact I've removed the older V2 examples, the example shown on this site is Version 3. The older version will no longer be supported, but is functional (for now). I highly suggest upgrading to the latest version of Google Maps.
In order to use the API you have to register for an API key.
Once you receive your key, you can begin to use the free version on your website.
Our free version is limited to 100 data points per call with a maximum of 500 calls (or hits) per day. Everytime a heat map is rendered, it constitutes a hit. For a monthly fee (no contract required, cancel at anytime), you can send as many points as you want, but are limited in the number of daily hits per the schedule below:
|Hits Per Day
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Optionally for a one time cost of US $2,499.00 you can license the .NET DLL to run one URL, however its up to you to implement the DLL into your own server environment. Contact us for multi URL licenses. We offer discounts for purchasing more than one month at a time. Contact us for details.
If you find that you have segmented your data by some population boundary (such as zip codes), that the population density of those areas overwhelms the 'rural' areas. Its best to prep your data to remove the concentration of these high population areas so that you only factor in your value, to denormalize the population factor. A good example is in a city center. If you capture 10 points in a 1 mile range, that is in affect a total value based by proximity when zoomed out a 10. A 10 is much larger than a 1, for say a point that is 10 miles a way, and its most certainly going to show the city center as HOT, and nearly ignore the value of 1 in the rural area. You would then divide in your data prep phase, each value of 1 in your city center by a number reflective of the density (such as area of represented) or some constant based on its density, to smooth out or lessen the impact of close adjacencies. The other method is to not rely on varied sized geometries (like postal codes or counties from state to state), that are not constitant, and use a more 'grid like' approach. This is a complex topic, and we can assit over the phone if needed.
You might find a point that is not in a dense area might not show as any heat, because it is being totally overweighted by other more dense areas. See the SetDecay() function, start with a value very small such as .0001. MOST users do or should not use this function however. If the number is too high, the heat map graphic will look distorted.
It might not seem intuative, that the heat map image changes as you zoom or pan. The image is calculated on what is in the view port, or what is on the screen, not on the entire dataset. If not, you would drill into certain areas and see one solid color. The idea was to give you drill down ability to see what is 'there', vs based on the entire dataset globally. We found this was a better trade off.
No not yet, but its often requested, and likely to make its way into a future release.
If your map is large, divide the mapsize in half [where you declare myHM.Init(400, 300);, change it to myHM.Init(200, 150);], the overlay in google will stretch to fit and be much faster. Also try submitting less accurate lat/lon values (e.g. 45.2352 instead of 45.23521233), makes the submits faster. Also try making your map smaller in pixels. If your using the large dataset method, you can also generate your datapoints server-side only in your proxy page, no need to pass the data from the client html page to the proxy page each time, just pass a key or some information via the data parameter, and then use that to generate the real data. You can also send different data based on the zoom level.
We offer free sample code for Google maps, but you can use our API with any system that can take a PNG file and overlay it on your map. Virtual Earth (Bing) doesn't support overlays, although we think it would be possible to integrate it, the output from our API is just a single PNG file. We have customers who have done other implementations in Google Earth or ESRI tools.
The free license you can submit 100 data points (or less) per call, but the commercial license there is no limitation. Matter of fact, the API is written to process thousands of points very quickly. We offer different options for your needs at a small fee. You'll find on the small set method, if your values are longer strings, you may be limited to less (like 60).
Contact us for details.