Units for data entry

HiGreg · August 1, 2017, 1:28am

I’m working on several scripts that will have units specified by the user. Am I missing any common measurement units or variations?

    'nm':1,
    'nano':1,
    'nanometer':1,
    'um':pcbnew.IU_PER_MM/1000.0,
    'micron':pcbnew.IU_PER_MM/1000.0,
    'micrometer':pcbnew.IU_PER_MM/1000.0,
    'mm':pcbnew.IU_PER_MM,
    'millimeter':pcbnew.IU_PER_MM,
    'milli':pcbnew.IU_PER_MM,
    'm':pcbnew.IU_PER_MM,
    'mil':pcbnew.IU_PER_MILS,
    'mils':pcbnew.IU_PER_MILS,
    'in':pcbnew.IU_PER_MILS*1000.0,
    'inch':pcbnew.IU_PER_MILS*1000.0,
    'inches':pcbnew.IU_PER_MILS*1000.0,
    "'":pcbnew.IU_PER_MILS*1000.0*12, # feet
    '"':pcbnew.IU_PER_MILS*1000.0, # inches
    
    # squared versions of measurements (three types: 2, **2, ^2)
    
    'nm2':1
    'nano2':1,
    'nanometer2':1,
    'um2':(pcbnew.IU_PER_MM/1000.0)**2,
    'micron2':(pcbnew.IU_PER_MM/1000.0)**2,
    'micrometer2':(pcbnew.IU_PER_MM/1000.0)**2,
    'mm2':(pcbnew.IU_PER_MM)**2,
    'millimeter2':(pcbnew.IU_PER_MM)**2,
    'milli2':(pcbnew.IU_PER_MM)**2,
    'm2':(pcbnew.IU_PER_MM)**2,
    'mil2':(pcbnew.IU_PER_MILS)**2,
    'mils2':(pcbnew.IU_PER_MILS)**2,
    'in2':(pcbnew.IU_PER_MILS*1000.0)**2,
    'inch2':(pcbnew.IU_PER_MILS*1000.0)**2,
    'inches2':(pcbnew.IU_PER_MILS*1000.0)**2,
    "'2":(pcbnew.IU_PER_MILS*1000.0*12)**2, # feet
    '"2':(pcbnew.IU_PER_MILS*1000.0)**2, # inches
    
    'nm**2':1
    'nano**2':1,
    'nanometer**2':1,
    'um**2':(pcbnew.IU_PER_MM/1000.0)**2,
    'micron**2':(pcbnew.IU_PER_MM/1000.0)**2,
    'micrometer**2':(pcbnew.IU_PER_MM/1000.0)**2,
    'mm**2':(pcbnew.IU_PER_MM)**2,
    'millimeter**2':(pcbnew.IU_PER_MM)**2,
    'milli**2':(pcbnew.IU_PER_MM)**2,
    'm**2':(pcbnew.IU_PER_MM)**2,
    'mil**2':(pcbnew.IU_PER_MILS)**2,
    'mils**2':(pcbnew.IU_PER_MILS)**2,
    'in**2':(pcbnew.IU_PER_MILS*1000.0)**2,
    'inch**2':(pcbnew.IU_PER_MILS*1000.0)**2,
    'inches**2':(pcbnew.IU_PER_MILS*1000.0)**2,
    "'**2":(pcbnew.IU_PER_MILS*1000.0*12)**2, # feet
    '"**2':(pcbnew.IU_PER_MILS*1000.0)**2, # inches
    
    'nm^2':1
    'nano^2':1,
    'nanometer^2':1,
    'um^2':(pcbnew.IU_PER_MM/1000.0)**2,
    'micron^2':(pcbnew.IU_PER_MM/1000.0)**2,
    'micrometer^2':(pcbnew.IU_PER_MM/1000.0)**2,
    'mm^2':(pcbnew.IU_PER_MM)**2,
    'millimeter^2':(pcbnew.IU_PER_MM)**2,
    'milli^2':(pcbnew.IU_PER_MM)**2,
    'm^2':(pcbnew.IU_PER_MM)**2,
    'mil^2':(pcbnew.IU_PER_MILS)**2,
    'mils^2':(pcbnew.IU_PER_MILS)**2,
    'in^2':(pcbnew.IU_PER_MILS*1000.0)**2,
    'inch^2':(pcbnew.IU_PER_MILS*1000.0)**2,
    'inches^2':(pcbnew.IU_PER_MILS*1000.0)**2,
    "'^2":(pcbnew.IU_PER_MILS*1000.0*12)**2, # feet
    '"^2':(pcbnew.IU_PER_MILS*1000.0)**2, # inches

devbisme · August 1, 2017, 3:13am

If you are working with physical units, you might want to check out the pint Python library.

HiGreg · August 1, 2017, 3:21am

Thank you, devbisme!

pint looks very interesting! I’m trying to do only length and area conversions suitable with pcbnew, with no dependencies to install for the average KiCad user.

If I get to the point of figuring out how to teach others how to install dependencies, I’ll take a look at pint!

ikletti · August 1, 2017, 9:04am

If you are going so far as to implement three notations for nanometer and micrometer, you could as well implement ‘thou’ for 1 mil.

rsfoto · August 1, 2017, 2:00pm

Hi,

I do not know for what that is going to be used, but if you list Mils and Inches as well as Microns and Millimeters ¿ what about Centimeter ?

I just ask because 1 Inch equals 2.54cm

regards Rainer

HiGreg · August 1, 2017, 2:26pm

Thanks ikletti and rsfoto! cm and thou are added!

paulvdh · August 2, 2017, 12:53am

“m” is for meter, not for milli meter.
centimeter [cm] is often used by “common people” but not much by engineers. They tend to stick to exponents with multiples of 3.
And cm is in lower case. not Centi…

Also, have you considered a default unit for cases the user does not explicitly specify a unit?
The most logical is probably to copy the settings from “Set units to mm/Inch” in the left margin when in EEschem / PcbNew. Maybe “guess” them from the locale when it is for external tools

HiGreg · August 2, 2017, 12:58am

Thank you! Yes, I forgot the *1000 for ‘m’. I know the “centi”, “milli”, and “nano” are not really proper (they’re only prefixes), but I’ve included them just in case. I changed the code to generate the squared values automatically. The non-squared list is now:

'':1,
'nm':1,
'nano':1,
'nanometer':1,
'nanometers':1,
'um':pcbnew.IU_PER_MM/1000.0,
'micron':pcbnew.IU_PER_MM/1000.0,
'microns':pcbnew.IU_PER_MM/1000.0,
'micrometer':pcbnew.IU_PER_MM/1000.0,
'micrometers':pcbnew.IU_PER_MM/1000.0,
'mm':pcbnew.IU_PER_MM,
'millimeter':pcbnew.IU_PER_MM,
'millimeters':pcbnew.IU_PER_MM,
'milli':pcbnew.IU_PER_MM,
'm':pcbnew.IU_PER_MM*1000,
'meter':pcbnew.IU_PER_MM*1000,
'meters':pcbnew.IU_PER_MM*1000,
'thou':pcbnew.IU_PER_MILS,
'mil':pcbnew.IU_PER_MILS,
'mils':pcbnew.IU_PER_MILS,
'cm':pcbnew.IU_PER_MM*10,
'centi':pcbnew.IU_PER_MM*10,
'centimeter':pcbnew.IU_PER_MM*10,
'centimeters':pcbnew.IU_PER_MM*10,
'in':pcbnew.IU_PER_MILS*1000.0,
'inch':pcbnew.IU_PER_MILS*1000.0,
'inches':pcbnew.IU_PER_MILS*1000.0,
"'":pcbnew.IU_PER_MILS*1000.0*12, # feet
'"':pcbnew.IU_PER_MILS*1000.0, # inches

erichVK5 · August 2, 2017, 12:59am

further food for thought:

eagle binary formats use 0.1 micron units

kicad legacy uses decimils, dmil, 0.1mil, and

pcb-rnd / gEDA PCB uses centimils, cmil, 0.01mil, for element dimensions in the absence of units in […] brackets, .

otherwise your list would cover most use cases.

pcb-rnd and gEDA PCB define these units in the units.h file:

http://igor2.repo.hu/cgi-bin/minisvn.cgi?cmd=cat&repo=pcb-rnd&path=trunk/src/unit.h

Cheers,

Erich.

HiGreg · August 2, 2017, 1:00am

This will be used for data entry and file formats for dealing with dimensions in KiCad.

HiGreg · August 2, 2017, 1:06am

Hmmm… This increases the ambiguity of the lonely “centi”, “nano”, and “milli”. I think I’ll remove those and maybe add the kicad legacy, and gEDA default format. The routine that will use this conversion will have a “default units” field and it’d be REALLY good to be able to specify those defaults with a unit. I’ll change the routine to accept a number as a default as well.

HiGreg · August 2, 2017, 1:22am

The routine I am developing is nominally for design rule files. But I will likely use it for text box entries in KiPadCheck.

As also suggested, the default for text boxes will be derived from the “inch/mm” user selection.

HiGreg · August 2, 2017, 1:31am

erichVK5, thanks for the link to pcb-rnd code! I’ve added “dmil” and “cmil” to the definitions.

HiGreg · August 6, 2017, 4:00pm

Thanks for all the feedback! It’s being incorporated into KiPadCheck.

The units list is now:

conversion = {
'':1,
'nm':1,
'nanometer':1,
'nanometers':1,
'um':pcbnew.IU_PER_MM/1000.0,
'micron':pcbnew.IU_PER_MM/1000.0,
'microns':pcbnew.IU_PER_MM/1000.0,
'micrometer':pcbnew.IU_PER_MM/1000.0,
'micrometers':pcbnew.IU_PER_MM/1000.0,
'decimicron':pcbnew.IU_PER_MM/10000.0,
'decimicrons':pcbnew.IU_PER_MM/10000.0,
'du':pcbnew.IU_PER_MM/10000.0,
'dus':pcbnew.IU_PER_MM/10000.0,
'dum':pcbnew.IU_PER_MM/10000.0,
'dums':pcbnew.IU_PER_MM/10000.0,
'mm':pcbnew.IU_PER_MM,
'millimeter':pcbnew.IU_PER_MM,
'millimeters':pcbnew.IU_PER_MM,
'm':pcbnew.IU_PER_MM*1000,
'meter':pcbnew.IU_PER_MM*1000,
'meters':pcbnew.IU_PER_MM*1000,
'km':pcbnew.IU_PER_MM*1000000,
'kilometer':pcbnew.IU_PER_MM*1000000,
'kilometers':pcbnew.IU_PER_MM*1000000,
'thou':pcbnew.IU_PER_MILS,
'mil':pcbnew.IU_PER_MILS,
'mils':pcbnew.IU_PER_MILS,
'dmil':pcbnew.IU_PER_MILS/10.0,
'dmils':pcbnew.IU_PER_MILS/10.0,
'decimil':pcbnew.IU_PER_MILS/10.0,
'decimils':pcbnew.IU_PER_MILS/10.0,
'cmil':pcbnew.IU_PER_MILS/100.0,
'cmils':pcbnew.IU_PER_MILS/100.0,
'centimil':pcbnew.IU_PER_MILS/100.0,
'centimils':pcbnew.IU_PER_MILS/100.0,
'cm':pcbnew.IU_PER_MM*10,
'centimeter':pcbnew.IU_PER_MM*10,
'centimeters':pcbnew.IU_PER_MM*10,
'in':pcbnew.IU_PER_MILS*1000.0,
'inch':pcbnew.IU_PER_MILS*1000.0,
'inches':pcbnew.IU_PER_MILS*1000.0,
'"':pcbnew.IU_PER_MILS*1000.0, # inches
"'":pcbnew.IU_PER_MILS*1000.0*12, # feet
'feet':pcbnew.IU_PER_MILS*1000.0*12,
'foot':pcbnew.IU_PER_MILS*1000.0*12,
}
# squared versions of measurements (three types: 2, **2, ^2)

davidsrsb · August 7, 2017, 1:22am

Metre is the correct spelling in many countries, hence “Metric”

HiGreg · August 7, 2017, 1:25am

Is ‘metre’ also used with all the SI prefixes too
(nanometre, centimetre, millimetre)?

HiGreg · August 7, 2017, 1:29am

I’ve added all units with ‘meter’ spelled ‘metre’ as well, including plurals.

Thanks!

paulvdh · August 8, 2017, 2:01pm

[quote=“HiGreg, post:17, topic:7281”]
I’ve added all units with ‘meter’ spelled ‘metre’ as well, including plurals.
[/quote]Isn’t this the job of a “translation package”?
I wouldn’t like it if this whole list gets sucked into a pull down menu and the menu won’t fit on the schreen because it has a gazillion options for the same.

HiGreg · August 8, 2017, 2:04pm

I don’t expect it to be a pull down. It is simply for text entry by users.

paulvdh · August 8, 2017, 3:08pm

You don’t expect it to be a pull down (or other) menu NOW, but code gets reused later in multiple ways.
And for text entry no sane user is going to type in words like “micrometer”.
I think that supporting the standarized SI units and a few basic imperoal ones should be enough, but it also seems like too much effort in too small a detail.