Check whether or not THERMALCONDUCTIVITYUNIT is correct

buildingSMART / IFC4.3.x-development

Repository to collect updates to the IFC4.3 Specification

Other

163 stars 83 forks source link

Check whether or not THERMALCONDUCTIVITYUNIT is correct #202

Open Moult opened 2 years ago

Moult commented 2 years ago

Original post

I see IfcThermalConductivityMeasure and THERMALCONDUCTANCEUNIT - the naming is different.

Proposal: Rename to match. I propose to rename to THERMALCONDUCTIVITYUNIT because it is the more common spelling in the existing set of derived unit enums.

aothms commented 2 years ago

According to qudt both exist

I didn't take the energy tbh to try and digest it and how it relates to the existing measures in IFC

Edit: corrected image

afbeelding

Moult commented 2 years ago

Oh wow yes this brings back highschool physics memories you're absolutely right. Ping @CyrilWaechter can you help decipher what is being requested in the original post?

Moult commented 2 years ago

Pushing this back to allocated since it's ambiguous what the actual proposal is.

CyrilWaechter commented 2 years ago

@Moult There is actually an issue. If you look at IfcMeasureResource and IfcDerivedUnitEnum pages different words are used.

	Derivation	IfcMeasureResource	IfcDerivedUnitEnum
Thermal conductivity	W/(m.K)	THERMALCONDUCTIVITYUNIT
Thermal transmittance	W/(m².K)	THERMALTRANSMITTANCEUNIT	THERMALTRANSMITTANCEUNIT
Thermal conductance	W/(m².K)		THERMALCONDUCTANCEUNIT

IfcDerivedUnitEnum contains 2 names for the same unit and none for thermal conductivity. Proposal: remove THERMALCONDUCTANCEUNIT from enum and add THERMALCONDUCTIVITYUNIT as described in IfcMeasureResource

Also side topic. All notation should be disambiguated. Notation W / m².K is ambiguous as it can be read (W/m²).K and W/(m².K). We should add parenthesis or have a clean mathematical formula with an horizontal line.

aothms commented 2 years ago

All notation should be disambiguated

Thanks to @Moult 's formula parsing Latex would be a great candidate now for this.

TLiebich commented 2 years ago

+1 for the proposed resolution (guess it was a writing error long time ago)

when checking the [http://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcDerivedUnitEnum.htm/IfcDerivedUnitEnum.htm)

currently all descriptions are empty for the enumerators, it could be used to refer to the corresponding measures and to default SI units. Maybe postponed until someone volunteers?

(a separate note to @aothms - is there a possibility in the XMI script to have the convention to list USERDEFINED and NOTDEFINED always at the end of the eunumeration, as it had been the case until IFC4.2? In my vire, it would improve the readability)