There is an issue when rounding in Autodesk. I think that typical standards state that when you 5 and over you round up and 5 and under you round down. This is the not the case in Civil3D. The attached image shows that 40.77 Plus 4.02 equals 44.78. If I was to ask anyone to add those up, you would nit get 44.78, but 44.79.
Apparently a long time ago some one thought it was thet other way around.
Let's just try an example:
40.76724 ≈ 40.77
+4.01737 ≈ +4.02
44.78461 ≈ 44.78
Looks perfectly legitamate to me.
Mark Green
Working on Civil 3D in Canada
troma's response is a great illustration of what is going on. The distance is rounded based on the length of the line and not based on the sum of two rounded station values. Excel works exactly the same way.
Regards,
Peter Funk
Sr Product Manager
Civil 3D
Autodesk, Inc.
For further reading:
https://forums.autodesk.com/t5/autocad-civil-3d-general/rounding-of-values/m-p/4794571#M240764
Mark Green
Working on Civil 3D in Canada
This is why I keep my WORKING files set to show lengths & stations to a precision of 4 decimal places -- it makes it easy to see things like this. The files that I actually plot from are set to more appropriate precision values.
Don Ireland
Engineering Design Technician
P.S. I don't know how many times I've had a corridor "drop to zero" because it extended past the profile. The corridor might have ended at 102+00.00 and the profile might have too so I was confused.
But when I changed the precision, I saw that the profile actually ended at 101+99.9985. My corridor ended 0.0015 ft beyond the profile. But because the profile was rounded to two decimal places, I thought it went to 102+00.00
Don Ireland
Engineering Design Technician
2020 and the rounding errors still persist. No adding... just labeling the surface at my survey point wrong. point is 100.005 and C3D labels it as 100.00
Garbage
Garbage? ... Maybe ... Maybe Not. Let's look.
@codee wrote:... just labeling the surface at my survey point wrong. point is 100.005 and C3D labels it as 100.00
Garbage
There are potentially two things going on:
____________________________________________________________________________
What is the actual elevation of your survey point?
This is from a survey I received for a surveyor. (I converted LDT points to C3D Cogo points)
A Line has been created, snapping one end to one particular point.
The elevation of that particular point is 1654.780 (See lower right)
The elevation display precision is controlled by the
Drawing Settings Elevation Precision setting, in this case: 3. (see lower left)
The elevation of line endpoint is 1654.77990000. Display of this elevation is controlled by "Units"
Rounding is based on the full precision of the point elevation, or surface elevation.
Christopher Stevens
Did you find this post helpful? Feel free to Like this post.
Did your question get successfully answered? Then click on the ACCEPT SOLUTION button.
Civil 3D rounds with the half-to-even rule.
https://forums.autodesk.com/t5/civil-3d-forum/round-normal/m-p/2644574#M126748
https://en.wikipedia.org/wiki/Rounding
John Mayo
Can't find what you're looking for? Ask the community or share your knowledge.