AutoCAD Map 3D General Discussion

AutoCAD Map 3D General Discussion

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Member
dchristensen
Posts: 3
Registered: ‎07-29-2009
Message 1 of 8 (382 Views)

mapdist command

382 Views, 7 Replies
12-14-2012 05:24 AM

When using the mapdist command the measurement is different from the actual line that I create. The map coordinates and the maptrack coordinates match. When I open a older drawing there is not an issue. Did I somehow change the origin of my template.

Any suggestions thanks

 

Here is sample from the command line

 

Command: _mapdist
Specify first point:
Specify second point:
Distance = 12.7513 (Foot)
Azimuth = 38 degrees (forward), 218 degrees (reverse)
Delta X = 15.0000, Delta Y = -0.0381

Product Support
phil_borycens
Posts: 202
Registered: ‎10-25-2011
Message 2 of 8 (341 Views)

Re: mapdist command

12-18-2012 09:31 AM in reply to: dchristensen

DIST calculates the distance between two points in space.
MAPDIST calculates the distance as measured on the earth's surface.

If no coordinate system is assigned to your drawing, DIST and MAPDIST will return the same values. If you assign a coordinate system based on a map projection for your DWG, then you will of course see a difference between the two measurements.

Here is an example. I assigned HARN/WO.OR-S to my drawing, drew a polyline, and measured the distance of that line using DIST, and then MAPDIST. Here are my results:

DIST
Distance = 7.8132

MAPDIST
Distance = 7.7772

I hope this makes sense :smileyvery-happy:



Phil Borycens
Member
dchristensen
Posts: 3
Registered: ‎07-29-2009
Message 3 of 8 (312 Views)

Re: mapdist command

01-15-2013 06:07 PM in reply to: phil_borycens
When drawing lines there is a difference between the line drawn and the mapdist measurement. Is there a way to draw the line so both distances are equal? David Christensen CAD/GIS Technician Marquette Board of Light and Power 2200 Wright St. Marquette, MI 49855 Office: (906) 228-0326 Cell: (906) 361-8237 Fax: (906) 228-0305
Member
matthew.micallef
Posts: 3
Registered: ‎05-31-2013
Message 4 of 8 (226 Views)

Re: mapdist command

05-31-2013 08:22 AM in reply to: phil_borycens

I am using AutoCAD maps 3d using the geo function to insert a map in the background.

 

I inserted two geographic points with the following locations:

 

35.7137N, 14.6553E

 

35.7730N, 14.7274E

 

I am using the mapdist function to find the geodetic distance between these two waypoints. The mapdist function returns 11395.8432m, whereas the true distance is 9260m.

 

Can you please give me an insight in this problem??

Member
matthew.micallef
Posts: 3
Registered: ‎05-31-2013
Message 5 of 8 (225 Views)

Re: mapdist command

05-31-2013 08:24 AM in reply to: matthew.micallef

To add to my previous post, I am using the WORLD MERACTOR -WGS 84 as the GIS co-ordinate system.

 

Product Support
phil_borycens
Posts: 202
Registered: ‎10-25-2011
Message 6 of 8 (218 Views)

Re: mapdist command

05-31-2013 04:38 PM in reply to: matthew.micallef

Hi Matthew:

 

Thank you for your posts, and especially for letting us know which coordinate system you are using. Rest assured that you are not going crazy, nor are you using the program wrong...

 

There is a known issue with MAPDIST in the WGS84 datum; distances are not calculated correctly. This is being tracked internally as 1206299. Thank you for bringing it back to our attention.



Phil Borycens
Member
matthew.micallef
Posts: 3
Registered: ‎05-31-2013
Message 7 of 8 (216 Views)

Re: mapdist command

05-31-2013 11:40 PM in reply to: phil_borycens
Thanks!

Sent from my iPhone
Valued Mentor
fcernst
Posts: 1,134
Registered: ‎01-07-2011
Message 8 of 8 (207 Views)

Re: mapdist command

06-01-2013 06:06 AM in reply to: phil_borycens

DIST
Distance = 7.8132

MAPDIST
Distance = 7.7772

 

I hope this makes sense :smileyvery-happy:

 

 


No, it doesn't make sense. Why is the geodetic distance shorter?

Fred Ernst, PE
C3D 2015
Ernst Engineering
www.ernstengineering.com
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