add a new unit failed

[bernd]

I tried to add a new unit to FreeCAD ...

https://github.com/berndhahnebach/FreeC ... e215960e05

I missed something ...

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from FreeCAD import Units 
Units.ElectricVacuumPermittivity

gives

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>>> 
>>> from FreeCAD import Units 
>>> Units.ElectricVacuumPermittivity
Traceback (most recent call last):
  File "<input>", line 1, in <module>
AttributeError: module 'Units' has no attribute 'ElectricVacuumPermittivity'
>>> 

wheras:

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from FreeCAD import Units 
Units.KinematicViscosity 

works fine:

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>>> 
>>> from FreeCAD import Units 
>>> Units.KinematicViscosity 
Unit: mm^2/s (2,0,-1,0,0,0,0,0) [KinematicViscosity]
>>> 

[Erni24]

Not sure, but there is a mistake in your formula. It has to be

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App.Units.ElectricVacuumPermittivity = App.Units.Unit(-3,-1,4,2)

The current is with a power of two!

[Kunda1]

any progress on this?

[yorik]

AttributeError: module 'Units' has no attribute 'ElectricVacuumPermittivity'

If I do this:

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grep -r KinematicViscosity *

I get:

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App/FreeCADInit.py:App.Units.KinematicViscosity           = App.Units.Unit(2,0,-1)
Base/Unit.cpp:    if(*this == Unit::KinematicViscosity          )       return QString::fromLatin1("KinematicViscosity");
Base/Unit.cpp:Unit Unit::KinematicViscosity          (2,0,-1); 
Base/Unit.h:    static Unit KinematicViscosity;

Make sure ElectricVacuumPermittivity is defined in these 4 locations too, probably one is missing... (My guess is the first one)

[bernd]

still no success ...

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$
$ grep -r ElectricVacuumPermittivity
src/App/FreeCADInit.py:App.Units.ElectricVacuumPermittivity = App.Units.Unit(-3,-1,4,2)
src/Base/Unit.h:    static Unit ElectricVacuumPermittivity;
src/Base/Unit.cpp:    if(*this == Unit::ElectricVacuumPermittivity  )       return QString::fromLatin1("ElectricVacuumPermittivity");
src/Base/Unit.cpp:Unit Unit::ElectricVacuumPermittivity(-3,-1,4,2);
$

https://github.com/berndhahnebach/FreeC ... it/502a778

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from FreeCAD import Units 
Units.ElectricVacuumPermittivity

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>>>
>>> from FreeCAD import Units
>>> Units.ElectricVacuumPermittivity
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: module 'Units' has no attribute 'ElectricVacuumPermittivity'
>>>

[bernd]

commit git commit c3f0288 and PR https://github.com/FreeCAD/FreeCAD/pull/2467 adds a unit to FreeCAD master but it does not work for me ...

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from FreeCAD import Units 
Units.VacuumPermittivity

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>>> 
>>> from FreeCAD import Units 
>>> Units.VacuumPermittivity
Traceback (most recent call last):
  File "<input>", line 1, in <module>
AttributeError: module 'Units' has no attribute 'VacuumPermittivity'
>>> 

[bernd]

works now for me

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from FreeCAD import Units 
Units.VacuumPermittivity

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Python 3.7.3 (default, Apr  3 2019, 05:39:12) 
[GCC 8.3.0] on linux
Type 'help', 'copyright', 'credits' or 'license' for more information.
>>> 
>>> from FreeCAD import Units 
>>> Units.VacuumPermittivity
Unit: s^4*A^2/(mm^3*kg) (-3,-1,4,2,0,0,0,0) [VacuumPermittivity]
>>>

OS: Debian GNU/Linux 10 (buster) (KDE/plasma)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.18231 (Git)
Build type: Unknown
Branch: master
Hash: 9dfcdb983f7dd1c5008b0f7d041247e30fc21a66
Python version: 3.7.3
Qt version: 5.11.3
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: German/Switzerland (de_CH)

[bernd]

Is there a difference between VacuumPermittivity and ElectricVacuumPermittivity If not we could rename it in material properties and use it as quantity instead of float. With this we would have all advantages from FreeCAD unit system for this material property. If it is not the same we schould addd ElectricVacuumPermittivity to the FreeCAD unit system.

https://github.com/FreeCAD/FreeCAD/blob ... #L158-L162

ping

[vocx]

works now for me

I remembered this thread.

Did you succeed in adding the unit?

With git commit 3500451a04 Werner added a unit. It seems he also added the corresponding property to src/App/Application.cpp, and src/App/PropertyUnits.h(.cpp), in addition to src/Base/Unit.h(.cpp).

See How to add other properties ,such as frequency ?

Frequency is now supported: git commit 3500451a0 and git commit d7ca604c9