Circle Tool ... specify diameter
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G,
Maybe it would be easier to move to Europe. :}
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I realize you can use the / operator as you suggest. However, if I input the Unit of measure in the VCB, ie., 6'/2 , I get a radius of 6'. Also, I don't believe you can input fractions either with the / operator. Am I entering info into the VCB using the wrong syntax?
I often am given xerox copies of old hand-drawn drawings or sketches to reproduce which have dimensions such as 6 5/16" Diameter. Is there a convenient way to enter this info using the Circle Tool in SU .... If not, then perhaps my original request would be useful.
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Actually if the only obstacle that does not let you use this option is that you need to enter the footage/inchage, there must be a solution for this (after all SU is developed in the States...)
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I see that as a need too. I think even metric users would have the same problem. If I want a circle with a diameter of 4.5mm, entering 4.5/2 gives me a diameter of 9.
You are right that there isn't a good way to enter a circle with a diameter of 6 5/16". Usually, in my head I can convert it to a simple fraction of (6*16)+5/16 = 101/16 for the diameter then double the bottom number to get the radius = 101/32.
Actually if it's gotta be right and I have to do (6*16)+5 in my head, I pull up the calculator real quick to make sure I'm not screwing something up. Some combination of poor math skills and poor self confidence I guess. Regardless it's one way of accomplishing your goal.
Being able to enter mathematical equations in the VCB would be a better solution and I hope that makes it to future versions.
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Now this is true with the decimal fractions - I've just tried (though I can imagine TIG coming up with an explanation and method about it).
Of course, as a workaround, we can always scale a circle to a specific size and the scale tool will work with its diameter but I know workarounds are just workarounds...
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G,
I think scaling is the best/quickest "workaround".
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6+5/16 ?
what number is that? 11/16" ?
6 5/16" -
Using decimal numbers /2 works fine... but with fractional inches it's useless... BUT the trick in halving fractional inches is the halve the whole inch part and double the fractional divisor...so...
6 5/16"
when /2 becomes
3 5/32"
It works for any combo...
BUT for 'odd' inches you do need also to add a 1/2" to the fraction, by adding the original fractional divisor !
11 7/8"
when /2 becomes
5 **8+**7/16" >> 5 15/16[/b]"
where the 1/2" is rendered as 8/16" - the 8 being the original divisor that is simply added to the top number [here 7 giving 15]...
So if you insist on using fractional inches then you need to learn some simple math tricks to halve dimensions...
Don't start going down halving fraction feet-and-inches !
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Decimal inches are handy. You can change back when doing standard dimensioning.
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@tig said:
So if you insist on using fractional inches then you need to learn some simple math tricks to halve dimensions...
right... though people that use fractional inches a lot generally have all that stuff ingrained in memory without needing to calculate (in the same way you know 7*8=56 without actually calculating it)
(well.. i guess we generally only have the 16ths and less ingrained.. if i start getting into 32nds and 64ths then i have to stop and think about it)..
but for me, the math trick for half of 11 7/8 would be 12/2 then subtract 1/16.. probably a lot of ways to arrive at the same answer but that's generally the way i do it on the fly..
regardless.. i think entering (11 7/8)/2 or even 11 7/8 ÷ 2 would be a lot less confusing than putting a + in the mix
[late Edit-] ah.. i see where you're putting the plus sign now.. the same place as in the example i used except i'd be putting a minus instead (11 16-1/16).. (11 & 16/16 -1/16).. not sure if id ever enter like that in the vcb but at least i see what you're talking about now
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Personally, I think all the math workaround suggestions miss the point: computers are supposed to do the math for us so we don't have to bother with it. It is a bit ridiculous that a sophisticated program running on an expensive computer can't even do all the simple math functions of a $10 pocket calculator, much less provide a user-friendly way to accept fractional or mixed unit expressions!
This isn't rocket science. Writing the code to parse an unambiguous arithmetic expression like (2' + 4mm)/2 is something any competent programmer should be able to do without breaking a sweat. Likewise, it is not much of a challenge to write the code to recognize a trailing "d" as a diameter specifier.
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Do not get into the habit of using /2, since SU has a significant bug: appending /2 works SOMETIMES -but only if you are dividing an integer by 2. If you type "1.5/2" you will not get a .75 radius as you expected. There is no warning in SU v.8; in fact this bug has not been fixed as of the 2014 version.
It would not be hard to parse the input line, then one could enter 6+5/16 for the mixed fraction since that's what we really mean for 6 5/16. (As we learned in 7th grade algebra, multiplication and division are always done before addition and subtraction -MDAS "My Dear Aunt Sally" rule).
It would be nice to be able to specify relative/absolute references, and variables too.
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