Sketcher dimensions

[DRFaust]

Item 1:

Is there a config setting that will hold sketcher to a normal amount of decimal places? I have in my config the default_decimal_places set to 3 but sketcher has 12 decimal places when I create a sketch before I edit them.

Item 2:

Another problem I am having in sketcher (per the attachment) is if I edit the dimension in the lower right corner from 2.00 to 3.00 the 2.50 dimension changes to 2.5000000000002 as you can see in the attachment. Sometimes I can not get an even dimension to work at all in one case I needed 6 but sketcher would either be 5.9999999999999 or 6.0000000000001. This is not acceptable for our CFD Analysis models because it creates small gaps between parts and causes meshing error due to small slivers of air between components.

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[HugoBarosa]

Hello!

That's probably due to accuracy problems, try to change your accuracy to a higher value then try again

[DRFaust]

We have to run Absolute Accuracy at .01so I have that set in my config file. I have tried a default config with it's accuraccy setting and still reacts the same way.

[TomD.inPDX]

Something in the solver is hanging that dimension. It happens a lot more in Creo than it ever happened before but it is fixable. I have not run across one that wasn't fixable in Creo 2.0.

Really, it should be reported to PTC support and get their eyes on it. You are certainly owed a good answer.

[DRFaust]

I turned a ticket into our corporate Creo Support Desk. A rep came to my desk yesterday.I explained and showed him the situation I am having in Sketcher. He agreed that it is a serious issue that should not act in the manor it is. He took a copy of the Creo part file along with my config and ui files. He said he would look into it and if needed turn it over to our PTC support team. I will keep this discussion upto date with any info I gather about the situation.

[TomD.inPDX]

Thanks Mike. Looking forward to the reply.

What version are you running?

[dschenken]

I have seen a number of similar questions and have not seen a substantial answer.

There should be some filtering for values in the CFD software to account for small value irregularities, as there is in all software that deals with imperfect results of numerical calculation.

The longer story is that there are few exact decimals in floating point computer math because the usual underlying number system is base 2. The values you see that appear exact are the result of some level of tweaking to get them to display correctly, aside from the numbers 0 and 1 or other even powers of 2. When the value that should be 2.5 is 2.50000...02 then it's probable there is an error in the calculation that does not result in 2.5.

Even in base ten, 1/3 + 1/3 + 1/3 <> 1, due to truncation of intermediate results. That it equals 1 in most calculators is due to using higher precision than is reported and then rounding the result.

Apparently in Sketcher this filtering is sometimes not hiding the inaccuracy as often as it used to.

[DRFaust]

I actually created the same exact feature the exact same way in WildFire 4.0 and it does not do the wrong dimensions. It performs perfectly as required. It must be what ever Creo is doing.

[HugoBarosa]

The problem is that Creo can't regenerate the dimensions for some reason, sometimes the problem is that the lines are not paralel but with a high accuracy such as .01 the system recognize them as paralel even if they are not.

[DRFaust]

Ok just wanted to let ya'all know there is still no solution or answer why I experience the issue with sketcher Creo 2.0 described in my original question. We have gone to M100 but the problem is still there.

I got the ticket pushed to our corporate guy that works directly with PTC and on 4/21/2014 he sent me an email stating "PTC has opened an SPR to investigate this issue. I'll let you know once I hear back. Sometimes SPR's lead to software fixes and sometimes they just lead to an explanation from R&D."

I have been contacting him every Friday since then but still no news from PTC. Guess I will have to wait and see what this Friday brings...

[TomD.inPDX]

I have had R&D drag their feet on a few cases where I couldn't even remember the issue when I received a reply. Sometimes the reply wasn't even in the ballpark of what my original problem was.

Since we pay for support, I believe we should expect a reply sometime with the current release to understand a problem is being actively looked at. You can escalate cases, and in this instance, I highly recommend it since it is such a fundamental part of accuracy that really must be addressed.

Of course, mine, Creo 2.0 M040 does this without issue. That is 12 place accuracy on the small numbers and 11 place on 59.5 (maximum allowed and no rounding applied).

[Patriot_1776]

What I'f found works sometimes is change the dim to 6.1, or some change fairly major. THEN change it back to 6.0.