Visualization: Geomap (Google)


[Editor's note: Google has made freely available the curious choropleth (colors by country) and graduated symbol (bubble) maps found in their Google Analytics tools as part of their charting - visualization kit. You set-up a HTML JavaScript object with the map parameters (country-value pairs or city-value pairs) and the colors and Google will make you an interactive Flash map (data brushing reveals country value on mouseOver) color coded via uninformative class breaks and terrible cartography linework (look at the US, Canada border) and a terrible world map projection (cylindrical with gross distortions in the higher latitudes). But it is free and fast and several regional base map are also available. There is certainly an oportunity for someone else to come up with a better API that uses the same function calls but draws better maps with meaningful data classes. Screenshot above is static, click on it to go to interactive version.]

Republished from Google Visualization.

Overview: A geomap is a map of a country, continent, or region map, with colors and values assigned to specific regions. Values are displayed as a color scale, and you can specify optional hovertext for regions. The map is rendered in the browser using an embedded Flash player. Note that the map is not scrollable or draggable, but can be configured to allow zooming.

We have two examples here: one that uses the regions display style, and another that uses the markers display style.

Regions Example

The regions style fills entire regions (typically countries) with colors corresponding to the values that you assign. Specify the regions style by assigning options['dataMode'] = ‘regions’ in your code.

Markers Example

The “markers” style displays a circle, sized and colored to indicate a value, over the regions that you specify. To use markers, you must include the following Google Maps API script with a key, unless you specify locations using latitude and longitude values.

Continue reading at Google . . .

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