Precision for Number Parameter in Family Editor

[r.robert.bell]

Situation:

1. I'm in the Family Editor, working on a family.
2. I create a parameter of the type: Number.
3. This parameter will be storing a constant that needs to be accurate to 8 decimal places.
4. After typing in the value 0.19921875 in the Formula field, the number is visually rounded, in both Value and Formula, to: 0.199219

While the Family Editor, it appears that Number type parameters are rounded to 6 decimal places. Is there any way to configure Revit to display max precision on Number type parameters while in the Family Editor? This is needed because I need to QC the values, and they can't be rounded.

I've also found that the number is rounded in the project environment when loading the family. (I overrode the precision setting in a schedule and can see the value is incorrect.) This is obviously not good.

Family Editor Rounding Number Type Parameters

[ToanDN]

Use a different parameter type.

By the way, what are you QC'ing?  Revit is for building, not molecule, design.

[barthbradley]

Did you change the Project Units?  Rounding to "Custom" and enter in more zeros?  

[RDAOU]

@r.robert.bell 

If there wont have more decimals coming in the future I would stick to numbers and do the following:

1. add an interim family Number Parameter (which will be the value in Percentage form - ie: 19.921875 => will kinda save you 2 decimals and allow the precision of Number parameter to display all digits in Family environment)
2. Keep "Value" which I assume is a shared parameter as a Number & its Formula = Percentage /100
3. In the project set formatting of the field Value to Fixed with 0.00000001 decimals => Displays the correct figure in Project environment

     

[r.robert.bell]

In the engineering field, it can be important to be that precise. And I do need to QC that value. I can't be reviewing a family and look at a rounded value without running into the question, "Is this right, or wrong?," and then being forced to replace the numbers because I'm unsure about them.

This is just a unitless number. Therefore, it should not be another unit type (such as length) because then I would need to normalize that parameter every time it is used in a formula. (blech)

[r.robert.bell]

There is no unit formatting for the Number type, either in the Family Editor or the project environment.

Project EnvironmentFamily Editor

[ToanDN]

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@r.robert.bell wrote:

In the engineering field, it can be important to be that precise. And I do need to QC that value. I can't be reviewing a family and look at a rounded value without running into the question, "Is this right, or wrong?," and then being forced to replace the numbers because I'm unsure about them.

This is just a unitless number. Therefore, it should not be another unit type (such as length) because then I would need to normalize that parameter every time it is used in a formula. (blech)

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Use Factor type as shown in my screenshot above then you can have as many decimal spaces as you see fit, and you don't need to normalize it in formulas either because Factor is technically Number.

[r.robert.bell]

It's quite a hack. I'm not a fan of it, because if someone is looking at the parameter to check the constant, they will think it is wrong. And then if they "fix" the value to the correct constant, the formulas using the "divide by" trick will have the wrong results. But thanks for trying to help.

[barthbradley]

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@r.robert.bell wrote:

In the engineering field, it can be important to be that precise.

Out of curiosity, what branch of engineering requires that kind of precision?     

[fernadonoso]

Hi @r.robert.bell @barthbradley @ToanDN @RDAOU 

I am trying to add a parameter to my Materials to calculate de Sustainability, and that parameter should be 1.6969E-14, so I have your same problem, did you manage to solve yours? I cant find btw the factor parameter type, could be that is not available in revit 2023?

Thanks in advance

[shujath36]

I am also facing same issue. There should be number category in project units to set the decimal places. I have added factor parameter from HVAC but it seems the decimal setting has to be made in every project.

Can I not fix the decimal places in the family itself without any trailing zeroes which should override the project settings? It is not at all feasible to set the decimal places in every project. 

Also, @r.robert.bell it is better to keep thread as unresolved unless any solution is provided as it will give wrong impression to the reader. 

[HVAC-Novice]

In cases where I need more than the 6 allowed decimal places I multiply that number by a thousand and then do with it what i want (calculate something or so), then i divide that result by a thousand. this is a bit workaround and you need to verify it is mathematically correct and adjust if needed (depending on what you calculated with that number).

this won't help if that number is the one you actually need to show.

In my case I calculated pressuredrop of devices based on airflow. in excel i had done a curve fit based on manufacturer data to get my exponents and factors. And sometimes those happened to be smaller than 10^-6. 

Alternatively make that sustainability parameter some unit that will naturally be in larger numbers. 

Before this thread I did not know HVAC units have a "Factor" that is a %.  Learn something new every day. What do you do with that, especially for HVAC? 

[FAIR59]

you can use a semi-scientific notation:

number = factor * 10^exponent, where the factor can be greater then 10.

factor parametertype Number

exponent parametertype Integer

number parametertype Number

first time entering the formula's , will still show a rounded number,

but opening the type-properties in the family-environment a second time will show the correct number.

this is the result in the project: