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Another rounding option for labels is needed.

Another rounding option for labels is needed.

The current options for rounding are:

  • Round Normal - (Do not be deceived, this is not the rounding you learned in school!)  Round normal uses two numbers to determine whether to round up or down. The first number is the number following the significant digit, and the second number is the value's very last digit  (Note: this very last digit is never revealed to the user as it is hidden in the system). Given the value 7.12345000000000009 and a desire to round to two decimal places the significant digit is in the hundredth's place of the decimal ("2").   The number "3" is the number following the significant digit and the number "9" is the value's very last digit. When the number following the significant digit is 6,7,8, or 9 the significant digit will increase by one, and if the number following the significant digit is 1,2,3, or 4 the significant digit will remain the same. If the number after the last significant digit is 5 then value's very last digit is looked at, and if that very last digit is even, the significant digit will increase by one, else it will reamain as it was.
    For example, the length property of an object may be revealed to the user as 6.24500000, but internally the value may be 6.245000001 in which case if the number is to be rounded to two decimal places, it would round down to 6.24 because the very last digit of the number is the odd number "1".
    This is not the result that most people would expect, nor is it predictable since it is impossible for the user to know what the very last digit of a number is.
  • Round Up - Rounds the significant digit up regardless of anything I.E. 123.221 rounds up to 123.23.
    This is rarely what people want.

The method of rounding that should be added:

  • Round half up - (This is the rounding you learned in school!)  Round half up uses one number to determine whether to round up or down. The number is the number following the significant digit. Given the value 6.245000001 and a desire to round to two decimal places the significant digit is in the hundredth's place of the decimal ("4").   The number "5" is the number following the significant digit. When the number following the significant digit is 5,6,7,8, or 9 the significant digit will increase by one, and if the number following the significant digit is 1,2,3, or 4 the significant digit will remain the same. In this case the number will round to 6.25.
4 Comments
doni49
Mentor

I haven't tested this myself but if you're correct then 7.12545000000000008 would become 7.13 while 7.12545000000000509 would become 7.12 which would make NO SENSE because the second unrounded number is higher than the first. 

 

That is NOT NORMAL.

Here is a video showing why you get the crappy 1 at the end of the number. 

 

The IEEEE Standard for Floating-Point Arithmetic controls how a computer program does rounding by default. 

 

 

The OP is incorrect in his assumption. The 1 at the very end has nothing to do with the rounding. The IEEEE Standard rounds to the nearest even value. So 7.125 will round to 7.12 and 7.135 will round to 7.14. 

troma
Mentor

@Civil3DReminders_com @doni49

C3D will round 1.55000 to 1.5

In school I was taught it should be 1.6.

This is the only difference between C3D 'normal' and "normal 'normal'". Which is right or wrong is not a straightforward answer.

 

There was a good summary of C3D's method here. Also a good debate on the merits of the various methods and the computer science behind it over here.

jmayo-EE
Mentor

Bump this up for the surveyors. I just did a small subdivsion and was reminded how the rounding needs to be fixed.

 

None of the solutions in the product will make a final map work without overriding or exploding metes and bound labels.

 

We need the third, most used option for rounding that we all learned in grade school and we cannot figure out why it is not in the product. SImply round to interger and then let us set the rounding option with the props dialog or right-click menu similar to leader pins/toggles/tails.

 

Please. Exploding and overriding defeats the purpose.

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