Author Topic: Dimension Precision  (Read 243 times)

Gymbo

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Dimension Precision
« on: July 05, 2018, 01:21:41 PM »
DC 23, there doesn't seem to be any information on DP, is there a table or something that explains it or is it just trial and error?
Regards,

Jim

Pearco

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Re: Dimension Precision
« Reply #1 on: July 05, 2018, 02:31:02 PM »
Jim;
Under options / General / Dimensions upper left side second box down, you can set the precision you need.


Jim
User since ProDesign 1.5

Gymbo

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Re: Dimension Precision
« Reply #2 on: July 05, 2018, 03:27:03 PM »
Thanks, I know that, what I don't know is what all those different Accuracies mean, they range from -7 to +15 and 1000 to .0001.

I have on more than one occasion played with the numbers and they worked fine once I got the hang of it, but I'm really a part time DesignCad user and I guess I should take better notes when I start playing with the accuracies. When I'm done with this project it might be 6 months before I'm back into DC. Maybe I'll try to make some kinda table.
Regards,

Jim

bdeck

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Re: Dimension Precision
« Reply #3 on: July 05, 2018, 09:15:03 PM »
Hi Jim,

When drawing a dimension in a macro:   eg        <precision [p] 

or changing it:  eg         change D_PRECISION, p

the effect of the variable p depends on the text format used in the dimension, eg decimal or fraction.

See the discussion of the "D_PRECISION" query/change parameter in the SDK for an explanation.
When setting dimension precision in a scroll box (in the dimension dialog or in the info box), the same rules apply.
Do not confuse dimension precision with accuracy. Dimensions are accurate to the limits of DC's double precision FP arithmetic.
Dimension precision refers only to the level of precision you choose to display.

Hope this helps.

Best Regards,
 
bd
« Last Edit: July 05, 2018, 09:17:29 PM by bdeck »

Gymbo

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Re: Dimension Precision
« Reply #4 on: July 06, 2018, 10:16:56 AM »
Thanks BD. After sending my last reply I spent some time refreshing my brain cells about Accuracy/Precision, decimal versus fractions and clear up a lot of the cobwebs that were causing so much confusion.

I looked for the discussion of the D_PRECISION parameter in the SDK portion of this forum  but couldn't find anything, could you point it out to me?
Regards,

Jim

bdeck

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Re: Dimension Precision
« Reply #5 on: July 06, 2018, 11:09:27 AM »
Even though "SDK" (software develompment kit) properly refers to a folder full of files related to basiccad and OLE, I often use "SDK" improperly to refer to the Macros17.hlp file.

Mea culpa.

Regards,
bd





DrollTroll

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Re: Dimension Precision
« Reply #6 on: July 06, 2018, 12:08:05 PM »
When your dimensions are using a decimal format, the precision value directly specifies the number of digits after the decimal point. For example, precision 5 gives you xx.yyyyy, and precision 2 would give you xx.yy
Negative values round the dimension data to the nearest power of ten, so -3 would round the value to the nearest 1,000 units, and -1 would round to the nearest 10. This may be useful if you are measuring very large distances (or large quantities of very small units), though I've rarely seen it used in practice.

When the dimensions are in a fractional format, then the precision value specifies the power of 2 in the fraction's denominator, so
  • 1 -> 1/2
  • 2 -> 1/4
  • 3 -> 1/8
  • 4 -> 1/16
  • 5 -> 1/32
etc.Hope that helps.

DT
25 years with DesignCAD

Gymbo

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Re: Dimension Precision
« Reply #7 on: July 06, 2018, 12:32:08 PM »
Thanks DT, it does help. I came to the same conclusions yesterday after looking at it for a while, although my conclusions weren't nearly as elegant as yours. I've already printed your reply.
Regards,

Jim