Expression Builder Question - (Angle / Azimuth Info)

[Anonymous]

How do you create a calcuation or text field for a SDF Line data file to show the angle / azimuth formation? If you can use the geometry to show the lenght of the line. Why couldn't you show the angle information? I know it's easy enougth just to draw a line and use the Line & Arc Information ribbon tool to show the information. But AutoCAD doesn't understand how extremely lazy I really am.

P.S. Wish I had Murph's phone number. I would call him none stop for support.

[jackie.ng]

It is probably because there is no such expression function to evaluate the angle/azimuth of an FDO geometry.

- Jackie

[jmurphy]

Because an FDO line feature is not (or does not have to be) a single segment. Look at the image attached, all three feature types are from one feature layer(SDF File). What is the angle of the line selected? What is the length of the polygon feature? What is the area of the point feature?

 BTW I may stop in one a day to try reading but don't have the time to give the quick replies like I did on the old system.

[Anonymous]

I know an SDF file can be a Point, LIne, and Poly objects. But I've created this SDF file to be a line type file only. So, yes, there should be a way to calculated the angle of said lines. Even it's segment a to b or even c to d.  

[Anonymous]

silly question, given your statement about "being lazy"

How about for being lazy, use the workflow tools to use Map Import to conver the SDF to drawing objects with Object Data.  The CAD objects will have a angle property.  Then you could export back to an SDF with the same name and include the angle with the export data.  Seems like this might work, depending on if you're only working with lines and not polylines.

Note - you might find that the angles are converted to radians and  you'd need to use an expression to convert back from radians to degrees....

Then, with an automated workflow, you'd only have to create the script once.....

Hope this helps.

[jmurphy]

What would happen if that line feature was an arc or polylines representing an arc. What about when you change corrdinate system?

I suggect Civil 3D and line labels.

[Anonymous]

if it is an arc or line segment of a polyline, then the angle value doesn't seem to come through - which is why I stated "line" and failed to make the direct statement. 

Murph is also correct in that this gets limited to the current coordinate system.  note if you change coordinate systems, such as from one that holds one property fixed (i.e. equal area) to another (equal angle or distance) such as from a Lambert Conforming Conic or Transverse Mercator into Lat-Long, you could see a dramatic difference.  but, it's all a matter of context - what "angle" are you capturing and why..... beware of taking the 3D world down to 2D..... 

[Anonymous]

Thank you to all who replied. Your thoughts and ideas have deemed very helpful. It seems that this very simple idea, is indeed a very complecated one. The workflow idea is the best answer for my situtiation at the moment. Maybe this is an item to add to the wish list of the next Map 3D software to come out. But again, thank you all for you help. I think the GIS world is a very fun and challenging place to be. And the community to roles along with it is incomparalbe.