AutoCAD Civil 3D

[#1]

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?

[#2]

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

[#3]

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

[#4]

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

[#5]

To round to the nearest tenth:

ROUND(X/0.1) *0.1

[#6]

Thanks Fred! Thats too easy

[#7]

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.

[#8]

Brian is correct.

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

[#9 · Accepted solution]

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.