[mapserver-users] Map Scale

[Puneet Kishor]

On Monday, November 11, 2002, at 06:32  PM, Vinko Vrsalovic wrote:

> Hello,
>
> I've been looking at the archives, but didn't find a clear explanation
> about this issue: The scale number shown by Mapserver is measured in
> what? and in what ways it can be useful for output?
>

technically scale is a ratio... hence, it doesn't have units 
technically. A scale of 1:xxx means 1 unit on your display (computer or 
paper) represents xxx units in the real world. So, 1 pix will be xxx 
pixels, 1 cm will be xxx cms, etc.

now customarily folks give different units to the different components 
of scale (the numerator and denominator). For example, Brits used to 
refer to 1" to 4 miles maps in olden times in India. Of course, it 
means what it says... 1" on the paper map is 4 miles in the real world.

In your application you can use some Javascript to give the user 
feedback of the area depicted on the display. Just use appropriate 
transformations to convert pixels to relevant geographic coords.

hth.