[OSM-talk] JOSM and scale

[Andy Robinson (blackadder)]

David Earl [mailto:david at frankieandshadow.com] wrote:
>Sent: 25 March 2008 5:30 PM
>To: Andy Robinson (blackadder)
>Cc: 'Frederik Ramm'; 'Lars Aronsson'; talk at openstreetmap.org
>Subject: Re: [OSM-talk] JOSM and scale
>
>On 25/03/2008 17:16, Andy Robinson (blackadder) wrote:
>> Vector editing software such as CAD packages are normally scale free at
>the
>> editing level. The co-ordinates are simply sufficient, especially if you
>> have the ability to draw a vector a specific distance from a point as a
>> polar ray or snapped relative to something else. Its only at plot time do
>> you decide what scale you wish to make your view. Perhaps if JOSM worked
>the
>> same way there would really be no need for a scale bar, especially when
>the
>> scale bar needs to read differently for vertical and horizontal
>projection
>> distances.
>
>I disagree. I often dictate 'postbox 10m after junction' or '... set
>back 30m from road' by my estimate, and I need to see what that amounts
>to in JOSM - though apparently I have been misled so far! Which would
>explain why my estimates haven't seemed to correspond to reality sometimes.
>

That's a normal type of requirement in CAD too. You know you are 10 or 30m
from another object so you use that object as the reference to draw the new
object a set distance away using one of the tools. If you have those sorts
of tools you find you don't need a distance/scale bar.

Cheers

Andy


>In Mercator distance is constant independent of orientation, isn't it?
>
>David