Map 101

Placing a basic map on a page

Adding a basic Google map with a single point to show the location of a Point if Interest needs only two lines to be added to the page.

All you need provide is the latitude (lat) and longitude (lon) of the point:-

(:gma-point lat=55.56789 lon=-4.76543 :)
(:gma-map :)

The first line (:gma-point lat=55.56789 lon=-4.76543 :) is needed to place the point on the map, at the latitude (lat) and longitude (lon) you provide.

The second line (:gma-map :) is needed to tell the system where on the page the map should appear.

How do I find the latitude and longitude?
If you don't know the latitude and longitude of the Point of Interest, then you can use our lat/lon finder map to locate it, and also generate the two lines needed to place the map on the page.

Simply pan and zoom the given map until the location of the Point of Interest is shown, then click on the point to generate the 2 lines, which can then simply be selected using the mouse, copied, and then pasted onto the required page.
What if there is more than one Point of Interest?
Once the map is on the page, any number of points may be added. The map will zoom automatically to show all the points plotted. Three points would just look like:

(:gma-point lat=55.56789 lon=-4.76543 :)
(:gma-point lat=54.32101 lon=-5.67890 :)
(:gma-point lat=55.43210 lon=-4.32101 :)
How can I tell which point is which if there is more than one?
Add a text entry to the line defining the point. Clicking the point opens a window showing the text. Using our above example:

(:gma-point lat=55.56789 lon=-4.76543 text='Interesting point one' :)
How do I get the satellite view instead of the map?
Add view=sat to the first line:

(:gma-map view=sat :)
What if the map is zoomed in too close to the Point of Interest to show anything useful?
Add a zoom command to set the map's zoom level. 14 is usually enough in such cases:

(:gma-map zoom=14 :)

Advanced options

There are more advanced options that allow more complex maps to be produced, with clickable links in the text, and lines between points.

Can I make a clickable link to open a Point of Interest?
Add a link entry to the line defining the point. Place the text of the line wherever you want the link to appear, it doesn't have to be on a line on its own. Clicking the link opens a window showing the text at the point. Clicking the point jumps to the location of the link in the page text. Using the above example:

(:gma-point lat=55.56789 lon=-4.76543 link='Interesting point one' :)

Can I draw lines on the map?
Using gma-line instead of gma-point will produce a map line. Any number of points can be connected by lines, but remember that at least two gma-line entries will be needed. Since more than one map line may be added, a new id= value has to be specified for each. All points on the first line would be id=1, all those on the second id=2, and so on. This allows any number of separate lines to be drawn on a map.

The gma-line entry only adds map lines, so it's still necessary to add gma-point marker entries to the page in order to have markers appear at each end of a line. For example a single map line, with a marker at each end, would need four lines as follows:

(:gma-line id=1 lat=55.56789 lon=-4.76543 :)
(:gma-line id=1 lat=55.76543 lon=-4.56789 :)
(:gma-point lat=55.56789 lon=-4.76543 :)
(:gma-point lat=55.76543 lon=-4.56789 :)
Can grid references by used instead of lat/lon pairs?
An extra function has been added to allow the lat/lon pair to be replaced by a grid reference consisting of two letters and two, three, or four pairs of eastings and northings. Spaces are not permitted inside the group, and there must be a space at the end. All other options work as described above:

(:gma-point (:llVgm NS12345678 :) :)

Notes

The zoom level is set by a number where 1 represent a whole-world view, and larger numbers represent closer views. The maximum zoom is usually 17, but this is not fixed. A number of areas will zoom to higher/closer views in satellite mode, with 21 being possible in some cases. It should be noted these are not found in Scotland, and 17 or 18 is the usual maximum within out area of interest.

Care should be taken not to specify pointless high zoom levels in satellite mode without checking that there exists anything to see. Many areas remain to be provided at high resolution, and have no imagery available above level 14 or so, in which case the default map view should be used for higher levels.

In many cases, the site also shows a separate Aerial view. This is unrelated to the Google map described here, and is purely a courtesy link to an alternative mapping system (usually, but not always) provided by Microsoft's Live Search. Live Search can access alternative satellite imagery compared to Google, and can therefore show detail sometimes not visible in the Google view. Occasionally, the Live Search view will not have any high resolution imagery available for a location. Due to the complexity (hassle) of regenerating the link and page entry, the link to the blank view is left on the page, in the hope that they may add the imagery at a later date.

As of April 2007, Multimap have revised the operation of their site, making it an attractive option to Live Search as it offers aerial photo imagery that comes from a commercial UK source, and covers many areas in detail unavailable from the American based sources.

Google will, however, remain the Built-in map of choice, because it can be coded into the page. This option is not, and probably will not, be available from Multimap. Live Search could also be coded, but since this code would need to be written from scratch, and the Google map code already exists, and both have similar areas of missing coverage, there seems to be no real point, since we can add the links easily once we have generated the data for our in-line Google map.

External links