[OSM-talk] Wrong scale in slippy map

Peter Childs pchilds at bcs.org
Thu Apr 23 11:45:52 BST 2009


2009/4/23 Jacek Konieczny <jajcus at jajcus.net>:
> On Thu, Apr 23, 2009 at 08:23:16AM +0000, Jukka Rahkonen wrote:
>> not mean that these countries are twice as large in the real life.  Scale bar
>> values, if presented in meters/feet, should be adjusted according to latitude.
>> Even then it cannot be correct for the whole map, but showing the corrrect scale
>> for the middle latitude of a would perhaps be the best compromise.
>
> If we could get two scales, at the top and at the bottom of the map,
> then it would give us even more correct information. But one scale will
> be enough, when correct. Incorrect meter/feet scale is quite useless and
> probably better would to not use such scale at all.
>

Call me stupid but are we not going to need a different scale bar for
North - South as well. Its like putting a Standard 1024x768 display on
a wide screen monitor everything gets stretched.

You could have more tiles at the equator than at the poles. Dreaming
that the world can be stretched to fit on a square is always going
have a problem somewhere.

Ideally you want a map so where a fixed distance is a fixed number of
pixels on screen and angles are correct at least for the bit of the
world you are currently looking at.... This should be doable at least
for higher zoom levels,

How you do this I'm not 100% sure.

Regards

Peter.




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