topic Re: Round up values in drawing table - calculating issue in 3D Part & Assembly Design

Round up values in drawing table - calculating issue

GI — Mon, 24 Aug 2020 07:04:28 GMT

Hi,

an issue here with calculated values in a drawing table (please see attached picture).

Using more digits after the comma is not an option.

If instead floor a ceil option is used the the wrong value goes correct, but the rest of the values for the total weight goes wrong.

Is there a way to have all values correctly calculated.

Thank you in advance.

Re: Round up values in drawing table - calculating issue

HamsterNL — Mon, 24 Aug 2020 07:48:13 GMT

In your formula, you are flooring the weight to two decimals and then you multiply by the number of items. My guess is that your weight is being rounded to 1.39, then multiplied by 196...which results in 272.44

So try this formula:

MASSE_TOT = floor((rpt_qty+asm_mbr_nbr_spares_pt)*asm_mbr_masse_kg,2)

Re: Round up values in drawing table - calculating issue

GI — Mon, 24 Aug 2020 09:08:00 GMT

Thank you. Results are close to the desired values, but still not 100% ok.

is must be

1268.88 1268.37 very close but not ok

351.36 350.4 close but, not ok

273.89 274.4 not ok

11.97 11.97 ok

Re: Round up values in drawing table - calculating issue

HamsterNL — Mon, 24 Aug 2020 09:27:52 GMT

Can you show more decimals in the UNIT column? (Something like 8 decimals)

Re: Round up values in drawing table - calculating issue

GI — Mon, 24 Aug 2020 09:34:43 GMT

Unfortunately not. ;-(

Re: Round up values in drawing table - calculating issue

KenFarley — Mon, 24 Aug 2020 11:17:48 GMT

Without seeing the actual numbers involved, I'm guessing what you want is:
(1) The unit mass is a rounded value, displayed using something like MASS[.2]. When this type of display is done, it rounds the number up/down depending on the rest of the digits.

(2) You want the total mass to be calculated as the total quantity (parts + spares) times this rounded value.

Trouble is, floor doesn't give you the rounded value, it just chops off the remainder of the decimal places, more a text operation than a mathematical one. The "trick" is to make the floor operation act like a rounding function by adding the appropriate half value. So, instead of floor(mass,2), you can use floor((mass+0.005),2). That will effectively "round up" when appropriate.

Re: Round up values in drawing table - calculating issue

GI — Mon, 24 Aug 2020 11:34:05 GMT

Thank you. Now it works as expected.

Have a nice day.