Dimensioning with precision...

[doughd]

Is there a way to change which way VW 2008 rounds up dimensions? I have a rectangle that is 8 3/8 wide. The dimension precision is set to 1/4", and the dimension reads 8 1/4". Why did VW round the dimension down, instead of up? Does it round to the nearest 1/4"? Or is it SUPPOSED to round up to the nearest 1/4" (or whatever the precision is set at on the oip)? The main reason I ask is because some dimensions round up and some round down, and this is making some dimensions contradict others. Here is the problem...

[Travis]

My dimensions always round up under the settings you mention. Is it possible the 8 3/8 length is actually 8.374? Or some other tiny amount less than 8.375? This seems to me to be the most likely reason you're rounding down.

Good luck,

[doughd]

If you take a look at the pdf file I attached, you'll see a very good example of what's going on. And this is not the only place where dimensions contradict others. 3'-7 1/4" + 4'-10" does not equal 8'-5". I know 1/4" isn't much out in the field, but I would like these to show correctly on the construction docs, without me having to correct each instance. Does anyone know how to fix this?

[doughd]

Oh, BTW, I have ALL these dimensions set at the same precision.

[Guest]

Go to File > Document Settings > Units and click on the Dimension Objects Primary tab. Choose the desired rounding position, and re-dimension your geometry.

[Chad McNeely]

ANY time you are rounding dimensions, there is the possibility of error. The remedy is to ensure that the objects are DRAWN with precision such that the dimension tool doesn't need to round.

Under File>Document Settings>Units check that your General Display settings have greater precision than your Dimension settings. Then see (draw a line next to each object) if the objects are actually precise, or if the dimension tool is in fact rounding. Adjust the geometry of the objects if possible, or increase (or fudge) the precision of the dimension to eliminate conflicts.

Attached (I think) are the General Display settings I use for most architectural drawing.

Best,

Chad

[Pat Stanford]

What Chad said. Also remember, that not all numbers can be converted exactly to a binary representation, so many numbers (floating point) in any computer program are actually approximations.

3'-7 1/4" + 4'-10" does not equal 8'-5"

If this is really 3'-7.126 + 4'-9.876 with rounding to the nearest .25, it does equal 8'5".

My best suggestion is to draw your dimensions with accuracy set a couple of notches higher than you will need. Instead of 1/4" rounding, draw them with 1/8 or 1/16" accuracy. Then your stackups should always come out correct to the 1/4 inch you actually want.

Pat

[jbrhwy]

Or come to the real world & start using metric, who would want to add 8' 3 3/8" + 2 5/16".

[doughd]

Ok thank you all for your input. One thing I'm still confused about: Does VW round to the nearest 1/4" (or whatever the precision is set to) or does it round UP to the nearest like Travis said at the top of this thread??

And...is there a way to change this?

[Chad McNeely]

Or come to the real world & start using metric

For a contrary view, see:

http://www.briontoss.com/education/archive/miscjuly00.htm

(snippet)

What I'll be addressing here is a tool that has long been touted as being a vast improvement over its predecessors, as being simple and easy and logical, yet which has never been accepted, anywhere, except by force of law, and which, after more than 200 years of concerted propagandizing effort, appears to have reached its peak of acceptance, and is beginning a slide into obscurity. That tool is the Metric System.

(/snippet)

[doughd]

Thanks Chad! That was an awesome article!

[doughd]

Oh, and jbrhwy, from reading that article, I believe I have to say for YOU to come to the real world, and make things alot easier on yourself!