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[Solved] Preventing Alibre from Rounding

Jake_Steidy

Senior Member
Hope everyone has been doing well.

Curious if there is any way to prevent what I am going to describe.

A 0.0625" line, 1/16", is drawn you offset that line by, N inches, you now have two lines that are supposed to be 0.0625", one is dimensioned the other is not dimensioned, mag/pos undefined. You go to dimension that line, and are presented with a dimension 0.063", which is not what the original line was drawn at. The dimension should be 0.0625". Is there anyway to prevent Alibre from creating these rounding design errors in the options menu?

Thanks,
Jake
 

simonb65

Alibre Super User
You can set the number of decimal places in the Properties-Units ...

1647452508029.png

Tick the box at the bottom to use the settings for every new part.
 

Jake_Steidy

Senior Member
Simon with the answers! Awesome thank you so much! Hope you are staying well.

Simon one more thing with this, so I prefer the visual representation of the 3 decimals, is there any way to change the precision used, to 4 decimals while still only visually seeing 3? Or is doing the trailing or leading 0 suppression my best bet for that, because I am trying that out now and it is not appealing visually to have different dimension lengths on a design.

Best,
Jake
 
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DavidJ

Administrator
Staff member
The precision setting only affects the display, not the internal precision.

If working with fractions, you could use the fractional display option.
 

Jake_Steidy

Senior Member
Hey David,

Thanks for the info, I've since changed back to my 3 decimal precision, as the extra decimal place begins to crowd drawings and the 0 suppression paired with the 4 decimals didn't look right visually either. Something I will add to my Alibre Version 2_ wish list.

Best,
Jake
 

simonb65

Alibre Super User
Simon one more thing with this, so I prefer the visual representation of the 3 decimals, is there any way to change the precision used, to 4 decimals while still only visually seeing 3?
As @DavidJ says, the internal calculations will be done to many many decimal places. The setting is purely to define what you see on screen and on documents. It will be rounded down to the displayed value for visual purposes. How it is rounded, I'm not sure if its truncated (last digits just removed) or rounded to the nearest up or down. Either way, just set it to whatever you need to accurately get that information across to whoever reads your drawings (or looks at your screen over your shoulder :)).
 

Jake_Steidy

Senior Member
So if it is done to N decimal places why does it round to 3 when I have 3 decimal places selected and it should be 4 decimal places? If it is only happening visually my line should not be changing length from 0.0625" to 0.063" when the dimension is just being visually rounded?

My example above is still the same problem I am trying to better understand. A 0.0625" line can exist happily in my Alibre world as a 0.063 'dimensioned' line. I take that happy '0.063"' line and copy, mirror, do whatever to make a second, and now when I go to dimension my 2nd line it is not the same original happy line even though it should be. I have to manually tell Alibre that 0.063" original line, which is actually 0.0625 does not equal 0.063" line even though it thinks that.
 

simonb65

Alibre Super User
So if it is done to N decimal places why does it round to 3 when I have 3 decimal places selected and it should be 4 decimal places? If it is only happening visually my line should not be changing length from 0.0625" to 0.063" when the dimension is just being visually rounded?
Because you asked it to only show you 3 decimal places. In this example it has rounded to the nearest next digit in order to accomplish your request!

Set it to 4 decimal places and suppress trailing zero's, it will show you what your expecting.
 

Jake_Steidy

Senior Member
In Exhibit A there is a line drawn up from the origin at a length of 0.0625", 1/16", then I drew a refrence line along that same line at 0.063" to show the height difference. I then offset the 0.0625" line to the left, the undefined line, when I selected the dimension in the Exhibit B picture and placed it Alibre changed the dimension of the line from 0.0625" to 0.063". As seen by the height difference.
Exhibit A.PNGExhibit B.PNG
 

simonb65

Alibre Super User
Not sure how you created those (looks like you've offset the reference line!), but if your asking to round to 3dp, then they will all show the same length. Increase the precision and you'll see the real lengths.

I don't understand why you have a small extension line at the top of the right line? If you edit each dimension, the dimension edit box will show the real length.

Again, I'm not sure what your workflow is here, but if you need to see the precision when designing the part, then set it appropriately before you start to avoid confusing numbers being thrown back at you.
 

Jake_Steidy

Senior Member
Something is still not correct, Alibre is rounding incorrectly. I changed to the 4 decimal precision and was able to do the same test above without error. So then why does that work if simply changing from 3 to 4 decimals is just supposed to be a visual change?

Simon more detailed explanation of my 2 images:
For that Exhibit A, I drew a line up from the origin, 0.0625", which is fully defined. Over that line starting at the origin I drew a 0.063" line to highlight the failure of Alibre's rounding. I then selected the Line <1> not the reference line or the length would've been longer on the undefined line, which it isn't as seen in Exhibit A. I then took the dimension leader and selected it, and when presented with the length of 0.063" instead of 0.0625" which was what the original length was, I accepted and had an incorrectly drawn 1/16" line.

Also it doesn't show the "real" length or I wouldn't be having this problem of a 1/16" line rounding to 0.063 which it isn't.
 

DavidJ

Administrator
Staff member
It doesn't re-size my offset line when I try this. Very easy to accidentally 'nudge' undefined figures when working with them. Could that be what happened?

How do you know which line you selected to offset (when they are on top of each other) - did you use the 'advanced selector' tool to differentiate between the line and the reference line ?
 

Jake_Steidy

Senior Member
It tells you if its a reference line or a line in the offset tool.

This is Exhibit C and D. Offset on the original 0.0625" line, then dimension the offset line, Which is the correct length by following the dimension leader from the left to the dimensioned line on the origin, I then place the dimension in Exhibit D and get the incorrect length.

Exhibit C.PNG Exhibit D.PNG
 

simonb65

Alibre Super User
I've just done those steps as you describe and it works as I would expect it to work!

3 decimal places and constructed as per you post (shorter left is a 1/16 line, longer on left is a 0.063 reference line, right line is an offset from the first 1/16 line)...
1647458735258.png

Change the display options to 4 decimal places and it shows exactly what was entered and the offset line the correct length...
1647458806443.png

Not sure exactly what your doing differently, but it works as advertised for me. Not sure if I can offer any further help on this one.
 

DavidJ

Administrator
Staff member
I don't see any rounding failure in decimal inches, in what way is it 'failing' 0.063 will (and should) be displayed for any length equal to or greater than 0.0625 and less than 0.0635, if 3 decimal place precision is chosen.
 

Jake_Steidy

Senior Member
The precision setting only affects the display, not the internal precision.

If working with fractions, you could use the fractional display option.
This is why I am confused David. If it only affects the display my lengths would be the same. It should not be changing a line that is 0.0625" into 0.063" because of rounding, you can call a 0.0625" a 0.063" because of sig figs but a 0.063" line isn't a 0.0625" line when designing parts
 

DavidJ

Administrator
Staff member
But nobody else is seeing this 'changing of length' when we follow your described procedure...
 

Jake_Steidy

Senior Member
I can make a video if you want to watch me do it. I can't tell you why its occurring on my system, was just trying to get an answer. Let me know if you want a video of it.

It doesn't show the popups, I don't know why. But the black line is drawn at 0.0625", the line next to it is offset. When the dimension leader is selected after moving it the dimension is 0.063" in the dimension popup, its confirmed and the length is changed from the original black line.

Video.

 
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NateLiquidGravity

Alibre Super User
I think I've seen this in other places too. Alibre will display the rounded up dimension in text boxes and sometimes accepting them will accept the rounded up dimension instead of it matching the original.
 
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