AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

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Valued Contributor
normans
Posts: 63
Registered: ‎03-15-2011
Message 1 of 9 (391 Views)
Accepted Solution

Rounding of values

391 Views, 8 Replies
12-10-2012 03:08 PM

Perhaps this is an easy one, if there are any? C3D 2012.

 

I have 2 surfaces that I am sampling and have the bands depicted in the attached. I would like to have all bands with 1 digit of precision and the values in the Cover Depth band add up. The Cover Depth is supposed to be subtracting the two but is often off by one digit. I have tried changing the rounding options in C3D but there is always disagreement between the data in the bands. 

 

I tried searching for this issue to no avail. Perhaps I need to have an expression to do the rounding is what one case eluded to. Seems that C3D may use a type of rounding that rounds to the nearest even number?

Civil 3D 2013 SP 2, 64 bit
Dell Precision T5600, 16 GB
Win 7 Professional 64 bit
Intel Xeon @ 2.0 GHz
NVIDIA Quadro 4000

This is one of my pet peeves with reviewers.When doing things by hand, you calculate the rounded value minus the rounded value and that's not very accurate. You want the actual value minus the actual value. If you label an elevation as 100.01, is that actually at that elevation? Not necessarily. It's at a number that ROUNDS to that value! Reviewers need to understand this concept when reviewing plans. Even though the drawing says it's 100.01, it not EXACTLTY 100.01!

 

For example, what is 100-90? Well, it's somewhere between 9 and 11. Any number between 9 and 11 is a solution to this equation. In other words, it's anywhere between 100.5-89.5 and 99.5-90.5. Round all numbers to the nearest 1 and they are both 100-90.

 

Thank you for listening, I'll end my rant now.

*Expert Elite*
Joe-Bouza
Posts: 4,992
Registered: ‎12-15-2008
Message 2 of 9 (364 Views)

Re: Rounding of values

12-10-2012 07:20 PM in reply to: normans

When you set the precision of the data band internally the decimals go on causing the funny math. Try round() in the label styles and expression for the data band

 

 

Thank you

Joseph D. Bouza, P.E. (one of 'THOSE' People) Civil 3D 2012 & 2013
HP Z210 Workstation
Intel Xeon CPU E31240 @ 3.30 Hz
12 GB Ram


Note: Its all Resistentialism, so keep calm and carry on

64 Bit Win7 OS
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BrianHailey
Posts: 2,815
Registered: ‎04-27-2005
Message 3 of 9 (354 Views)

Re: Rounding of values

12-10-2012 08:58 PM in reply to: normans

I don't think you can add expressions to section view bands. Hopefully I'm wrong and someone will correct me.

Brian Hailey
CAD-1.com
My Blog
*Expert Elite*
Joe-Bouza
Posts: 4,992
Registered: ‎12-15-2008
Message 4 of 9 (339 Views)

Re: Rounding of values

12-11-2012 04:47 AM in reply to: BrianHailey

Maybe not. I guess I guessed wrong. The expression builder is there but I cant figure out what function can round the decimal? they all seem to round, ciel, trunc to the nearest integer

 

sect-expression.PNG

Thank you

Joseph D. Bouza, P.E. (one of 'THOSE' People) Civil 3D 2012 & 2013
HP Z210 Workstation
Intel Xeon CPU E31240 @ 3.30 Hz
12 GB Ram


Note: Its all Resistentialism, so keep calm and carry on

64 Bit Win7 OS
Valued Mentor
fcernst
Posts: 1,107
Registered: ‎01-07-2011
Message 5 of 9 (330 Views)

Re: Rounding of values

12-11-2012 06:15 AM in reply to: Joe-Bouza

To round to the nearest tenth:

 

ROUND(X/0.1) *0.1

Fred Ernst, PE
C3D 2015
Ernst Engineering
www.ernstengineering.com
*Expert Elite*
Joe-Bouza
Posts: 4,992
Registered: ‎12-15-2008
Message 6 of 9 (320 Views)

Re: Rounding of values

12-11-2012 07:37 AM in reply to: fcernst

Thanks Fred! Thats too easy

Thank you

Joseph D. Bouza, P.E. (one of 'THOSE' People) Civil 3D 2012 & 2013
HP Z210 Workstation
Intel Xeon CPU E31240 @ 3.30 Hz
12 GB Ram


Note: Its all Resistentialism, so keep calm and carry on

64 Bit Win7 OS
Valued Contributor
normans
Posts: 63
Registered: ‎03-15-2011
Message 7 of 9 (308 Views)

Re: Rounding of values

12-11-2012 09:27 AM in reply to: normans

I am following your line of thought from your much appreciated suggestions. I'm not quite there yet though.

 

BH - I've only read about the use of expressions, not used them yet, but I'm willing. I'm wondering if what you said is true - that you can't use expressions in Data Bands?

 

Perhaps I will just add a note to the effect that internal rounding is causing the issue for now, but I would really like to resolve this as I am sure that it will aid me in the future.

 

Thanks again.

 

 

 

 

Civil 3D 2013 SP 2, 64 bit
Dell Precision T5600, 16 GB
Win 7 Professional 64 bit
Intel Xeon @ 2.0 GHz
NVIDIA Quadro 4000
*Expert Elite*
Joe-Bouza
Posts: 4,992
Registered: ‎12-15-2008
Message 8 of 9 (304 Views)

Re: Rounding of values

12-11-2012 09:42 AM in reply to: normans

Brian is correct.

 

I jumped the gun on the labelstyle expressions. The section data node does not have an expression node

 

section data.PNG

Thank you

Joseph D. Bouza, P.E. (one of 'THOSE' People) Civil 3D 2012 & 2013
HP Z210 Workstation
Intel Xeon CPU E31240 @ 3.30 Hz
12 GB Ram


Note: Its all Resistentialism, so keep calm and carry on

64 Bit Win7 OS
*Expert Elite*
BrianHailey
Posts: 2,815
Registered: ‎04-27-2005
Message 9 of 9 (288 Views)

Re: Rounding of values

12-11-2012 02:56 PM in reply to: normans

This is one of my pet peeves with reviewers.When doing things by hand, you calculate the rounded value minus the rounded value and that's not very accurate. You want the actual value minus the actual value. If you label an elevation as 100.01, is that actually at that elevation? Not necessarily. It's at a number that ROUNDS to that value! Reviewers need to understand this concept when reviewing plans. Even though the drawing says it's 100.01, it not EXACTLTY 100.01!

 

For example, what is 100-90? Well, it's somewhere between 9 and 11. Any number between 9 and 11 is a solution to this equation. In other words, it's anywhere between 100.5-89.5 and 99.5-90.5. Round all numbers to the nearest 1 and they are both 100-90.

 

Thank you for listening, I'll end my rant now.

Brian Hailey
CAD-1.com
My Blog
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