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CAD Forums => Vertically Challenged => Land Lubber / Geographically Positioned => Topic started by: AARYAN on March 10, 2014, 07:14:30 AM

Title: Find Semi Major Axis
Post by: AARYAN on March 10, 2014, 07:14:30 AM

Hi All,

Please help

Is there a way to know the semi major axis of a selected coordinate system in Autocad Map 3d through AutoLISP or by any other mean.

Any help would be highly appreciable.

Regards

Title: Re: Find Semi Major Axis
Post by: mjfarrell on March 11, 2014, 08:06:33 AM

www.epsg.org/guides/docs/g7-2.pdf‎

Title: Re: Find Semi Major Axis
Post by: Pointdump on March 12, 2014, 08:58:38 AM

Michael,

Link doesn't work.

Dave

Title: Re: Find Semi Major Axis
Post by: Kerry on March 12, 2014, 09:00:44 AM

try
http://www.epsg.org/guides/G7-2.html

and select the PDF

Title: Re: Find Semi Major Axis
Post by: AARYAN on March 13, 2014, 01:39:05 AM

Thanks for the link Michael.

Title: Re: Find Semi Major Axis
Post by: AARYAN on March 14, 2014, 03:30:08 AM

Hi Michael,

Is it possible to get these details from any Programming language by passing the argument to the function as code in AutoCAD Map 3d itself.

e.g if it is possible from VLISP then it would be something like (FunctionName code) would return (equatorialradius polarradius).

thanks for you help.

Title: Re: Find Semi Major Axis
Post by: mjfarrell on March 14, 2014, 01:49:34 PM

doubtful


what are you trying to do with that information anyway?

Title: Re: Find Semi Major Axis
Post by: AARYAN on March 14, 2014, 03:03:40 PM

I am trying to create an AutoLisp program which will create geographic grids in model space inside a closed polyline at user interval in deg mins or secs and also the markers on a polyline at user specified geodetic distance etc..

For this I want the user to select the available coordinate systems which I can get from ade_proj* functions,
and when the user selects the coord system I can get the code of the selected system but not the details required such as Equatorial radius and polar radius which are useful for the above said functions.

Thanks

Title: Re: Find Semi Major Axis
Post by: mjfarrell on March 14, 2014, 03:54:44 PM

I'm thinking you may have to flog the internet to get that information and put in a table to use

I would think that adding to it as the need for each different system came around would be practical.