topic Re: Expressions Error in Collaboration with other software

Expressions Error

Anonymous — Thu, 09 Aug 2018 04:33:48 GMT

I'm having problems trying to use Skin Component Area in expressions. The error I'm receiving is "Expressions contains circular reference"

Is this the correct approach/parameters to do calculations with for complex profiles with multiple materials?

Re: Expressions Error

Anonymous — Thu, 09 Aug 2018 04:44:53 GMT

Having difficulty getting parameters for openings to work in expressions too. Invalid values using the surface area parameters, but is working for actual window objects

Re: Expressions Error

Barry Kelly — Thu, 09 Aug 2018 05:47:43 GMT

Complex profiles do not have skins like a composite wall does.
They can look the same but a complex profile is just a bunch of extruded fills that can be any shape and in any position in relation to each other.
Not like the parallel skins of a composite wall or slab.

Barry.

Re: Expressions Error

Anonymous — Thu, 09 Aug 2018 06:18:57 GMT

That's a shame. Does that mean the skin components cannot be converted or used in any way for expressions at all?

Re: Expressions Error

Barry Kelly — Thu, 09 Aug 2018 06:54:42 GMT

The only skin information that I can see that can be used in the property expressions is ...

And of course this is only for composite walls.

Barry.

Re: Expressions Error

Anonymous — Thu, 09 Aug 2018 08:21:58 GMT

Guess I'll have to investigate a bit further to see if I can get what I want

Thanks Barry

Re: Expressions Error

Laszlo Nagy — Thu, 09 Aug 2018 18:43:06 GMT

Andrew,

Maybe you could post exactly what you are trying to achieve, plus show the exact Expression you created to achieve that. From that point, we could help you further, hopefully.

Re: Expressions Error

Anonymous — Fri, 10 Aug 2018 00:33:59 GMT

The initial problem worked itself out. I've not another issue that is somewhat relevant, so I'll keep it in this thread.

I'm trying to accurately measure the length of skirting of all walls with the material. There doesn't seem to be a parameter to do this, but there is one to detect doors.

I'm working around it by trying to make expressions to detect the wall type/material and then choosing a formula. I've read that you can make a true/false statement with numeric values but am not sure how to do it.

IF ( ( Skirting - Thickness} > 0 ), TRUE, FALSE )

Thanks

Re: Expressions Error

Barry Kelly — Fri, 10 Aug 2018 01:23:32 GMT

So your skirting is part of the wall composite and you are using a profile modifier to adjust the skirting thickness?
You might be able to use this as modifiers can be used in property expressions.
I will have to have a play with it over the weekend.

If your skirting was a separate object or beam then it would be easy, but of course it would not automatically cut for openings.

Barry.

Re: Expressions Error

Anonymous — Fri, 10 Aug 2018 01:58:50 GMT

Yes it's part of a wall complex profile. I'm having trouble getting the expression to return TRUE/FALSE.

Looking at the FAQ, this is what I want to achieve

"Can I convert a numeric calculation result to a simple polar question answer (like yes/no or true/false)?
Yes! Typical design validation scenarios are based on polar questions clarifying if your design meets the requirements from a certain aspect or not. You can create a separate property with True/False data type and create an expression which sets the value to True or False depending on the calculated value of the numeric property the validation is based on."

The above says its possible, but I can't find any examples. I seem to be generally having problems getting one data type to another. Are there any particular tips or tricks for me to learn?

Re: Expressions Error

Anonymous — Fri, 10 Aug 2018 02:17:03 GMT

On a similar note, I'm trying to do the same thing in order to try and detect if a door position is external or not in order to have an expression use it to determine if its a single/double architrave.

Re: Expressions Error

Barry Kelly — Fri, 10 Aug 2018 02:22:48 GMT

So just to confirm we are both going down the same track, you have a complex profile something like this that has modifiers to allow for a skirting (or not if zero width)?

Barry.

Re: Expressions Error

Anonymous — Fri, 10 Aug 2018 02:30:46 GMT

Hi Barry,

Yes that's what I have, along with a few more components overlapping (not sure if that matters).

Re: Expressions Error

poco2013 — Fri, 10 Aug 2018 02:40:30 GMT

Not Sure this is your problem but:

IF ( ( Skirting - Thickness} > 0 ), TRUE, FALSE ) -- assuming skirting and thickness have the same units -- if not they must be properly cancelled out.

Is a valid expression. However, the data type returned by the expression must match the data type configured (definition value) for the expression. Generally the string type is set as default. in your case, for the above, the expression definition data type must also be set to TRUE/FALSE.

Yes you can convert from one data type to another but the units within the expression must match that of the value definition data type. However, this can't be done for true/false since there is no equivalence between a number and a Boolean value. 1 does not equal true as in some programing languages. You must use a logical (if) statement.

example:

area/m = length
volume/m = area
area * m2 = volume
area/m2 = number -- no units

IOW you must be sure to cancel out units correctly to match that of the definition value type.

Hope this helps unless you have some other issues?

Re: Expressions Error

Anonymous — Fri, 10 Aug 2018 02:53:24 GMT

Sorry, the "Skirting - Thickness" is the modifier name, not an operation. The data value of "Skirting - Thickness" should be a statement of true/false from my understanding - matching the required expression definition data type.

Screenshot:

Re: Expressions Error

Barry Kelly — Fri, 10 Aug 2018 03:01:56 GMT

I was going to look at it on the weekend, but my interest has been piqued.

This will hopefully explain it.
Use 'IF' to test if the modifier is true or false - 1 or 0 in this case as we can then multiply it by the wall length.
Don't use zero as the comparison value as there will be small errors in the skirting width - 0 may actually be 0.00001.
Set a unit of measurement to the comparison value so you are comparing a length with a length.
Now just multiply it by the conditional wall length.
Make sure the 'Data Type' is 'Length' and be sure to associate the property with walls.

Barry.

Re: Expressions Error

poco2013 — Fri, 10 Aug 2018 03:24:20 GMT

To add to what Barry said -- and I believe we are saying the same thing.

in your if statement you are comparing a dimension ed number to a non-unit number. They must be the same.

simply multiply the 0 by whatever units the profile is so they are the same.

Re: Expressions Error

Anonymous — Fri, 10 Aug 2018 03:49:36 GMT

This works perfectly. Definitely jogged up some old memories from coding classes a long time ago.

With that said, I feel like the TRUE/FALSE data type is a bit useless? Using my next task as an example - if I wanted to get the position of my window/door to determine architraves on one or both sides - I'd have to obtain it from a string parameter and use the text editor functions to have it return TRUE/FALSE?

Thanks for both of your help.

Re: Expressions Error

Barry Kelly — Fri, 10 Aug 2018 04:03:44 GMT

Andrew wrote:
if I wanted to get the position of my window/door to determine architraves on one or both sides - I'd have to obtain it from a string parameter and use the text editor functions to have it return TRUE/FALSE?

I am a bit confused what the position would have to do with architraves.
Wouldn't this be a parameter you turn on/off in the object.
That would be your true/false.
If true then it is (window width +window height)*2 and for doors door width + door height *2.

This doesn't allow for full height windows or corner windows if that is what you mean by position.
But architraves which are added as part of the object will best be calculated in the object.
Which may be a problem if you are using the Graphisoft doors and windows (I am unfamiliar with them as I don't use them).

Barry.

Re: Expressions Error

poco2013 — Fri, 10 Aug 2018 04:04:42 GMT

Andrew wrote:
I'd have to obtain it from a string parameter and use the text editor functions to have it return TRUE/FALSE?

Correct - However, string functions can compare strings directly to return a true/false. pretty much the same as using a if statement.

Keep in mind that this feature is a first issue -- so as deficiencies become apparent, I ASSUME Graphisoft will improve this feature in the future??