Is there an Omega sign available?

  • Thread starter Svenn Are Bjerkem
  • Start date
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Svenn Are Bjerkem

Guest
Hi,

to annotate my symbols I use

strcat(cdsParam(1) " Ohm")

for the illabel. Notice that it is a must to have that space, otherwise
1 Ohm become 1Ohm which is 10 hectometer. Nonsense in respect to
resistors, but how do you interpret
r=1Ohm
when looking quickly at it.

This make the symbols a bit more readable, specially when milli is in
play as 10m is more often read as 10 meters than 10 millisomething.
Specially a problems with transmission lines that are 10mm. Imagine
this: length=10m. So I decided to take the extra work to insert

strcat(cdsParam(2) "m")

to avoid stupid problems like this. Here the space is not needed as
there will be no problem with misunderstanding. 10m m does not look as
good as 10mm

For resistance and conductance there are the greek symbol Omega used.
(conductance on the head) Are these symbols available in any font used
with cadence and how do I use them. I tried

strcat(cdsParam(1) intToChar(234))

as ascii 234 is supposed to be the Omega in the extended ascii according
to www.lookuptables.com. Doesn't work as far as I can see, but no need
to hunt for something if it doesn't exist in the first place.
--
Svenn
 
On Wed, 7 Sep 2005 10:50:22 +0200, Svenn Are Bjerkem <svenn.are@bjerkem.de>
wrote:

Hi,

to annotate my symbols I use

strcat(cdsParam(1) " Ohm")

for the illabel. Notice that it is a must to have that space, otherwise
1 Ohm become 1Ohm which is 10 hectometer. Nonsense in respect to
resistors, but how do you interpret
r=1Ohm
when looking quickly at it.

This make the symbols a bit more readable, specially when milli is in
play as 10m is more often read as 10 meters than 10 millisomething.
Specially a problems with transmission lines that are 10mm. Imagine
this: length=10m. So I decided to take the extra work to insert

strcat(cdsParam(2) "m")

to avoid stupid problems like this. Here the space is not needed as
there will be no problem with misunderstanding. 10m m does not look as
good as 10mm

For resistance and conductance there are the greek symbol Omega used.
(conductance on the head) Are these symbols available in any font used
with cadence and how do I use them. I tried

strcat(cdsParam(1) intToChar(234))

as ascii 234 is supposed to be the Omega in the extended ascii according
to www.lookuptables.com. Doesn't work as far as I can see, but no need
to hunt for something if it doesn't exist in the first place.
Click to expand...
Svenn,

I don't think anything outside the 7-bit ascii character set is available. Not
really sure who in their right mind would interpret 1Ohm as 10 hectometers (does
anyone actually use the unit hectometer anyway?).

Not sure how appropriate making your labels something like
strcat(cdsParam(1) " Ohm") is anyway. The point of cdsParam() is that the user
can choose (via effective CDF, or edit->component display) what gets displayed
in placeholder 1, 2, 3 etc. So what is to stop them replacing "r" with "tc"
(say). Or annotating operating point informations (like current). Showing a
current value (e.g 1uA) as "1u Ohm" will surely be rather confusing?

Regards,

Andrew.
 
In article <sjruh11rrodkm57sm43eououhif6dfhkvl@4ax.com>,
andrewb@DcEaLdEeTnEcTe.HcIoSm says...
I don't think anything outside the 7-bit ascii character set is available. Not
really sure who in their right mind would interpret 1Ohm as 10 hectometers (does
anyone actually use the unit hectometer anyway?).
Click to expand...
Nobody, it it just annoying. If the Omega sign is not available, then it
is not available

Not sure how appropriate making your labels something like
strcat(cdsParam(1) " Ohm") is anyway. The point of cdsParam() is that the user
can choose (via effective CDF, or edit->component display) what gets displayed
in placeholder 1, 2, 3 etc. So what is to stop them replacing "r" with "tc"
(say). Or annotating operating point informations (like current). Showing a
current value (e.g 1uA) as "1u Ohm" will surely be rather confusing?
Click to expand...
I think the unit of the property is as important as its magnitude. It
would be nice if cdsParam() also fetched the unit type from CDF.

Hardcoding things is always bad, but in this case the symbol in
discussion is a top level symbol with parameters defined by me and
there is no obvious need for the user to change what parameter is
visible.

--
Svenn
 
On Thu, 8 Sep 2005 07:56:12 +0200, Svenn Are Bjerkem <svenn.are@bjerkem.de>
wrote:

I think the unit of the property is as important as its magnitude. It
would be nice if cdsParam() also fetched the unit type from CDF.

Hardcoding things is always bad, but in this case the symbol in
discussion is a top level symbol with parameters defined by me and
there is no obvious need for the user to change what parameter is
visible.
Click to expand...
In which case you might as well make it:

strcat(instId~>paramName " Ohm")

and miss out cdsParam(). That way there would never be any confusion!

Regards,

Andrew.
 
"Svenn Are Bjerkem" <svenn.are@bjerkem.de> wrote...
to annotate my symbols I use
strcat(cdsParam(1) " Ohm")

for the illabel. Notice that it is a must to have that space,
otherwise 1 Ohm become 1Ohm which is 10 hectometer. Nonsense
in respect to resistors, but how do you interpret r=1Ohm
when looking quickly at it.
Click to expand...
Although the name of the person after whom the unit is named is Ohm, which
is a proper noun and takes an initial capital, the SI unit is not a proper
noun and is named ohm, with a lowercase 'o'. So, the confusion is less
likely to arise: your example is 1ohm, which is not likely to be misread as
ten hm.
 
In article <L5rVe.185260$Hk.124359@pd7tw1no>, mdkendall@hotmail.com
says...
"Svenn Are Bjerkem" <svenn.are@bjerkem.de> wrote...
to annotate my symbols I use
strcat(cdsParam(1) " Ohm")

for the illabel. Notice that it is a must to have that space,
otherwise 1 Ohm become 1Ohm which is 10 hectometer. Nonsense
in respect to resistors, but how do you interpret r=1Ohm
when looking quickly at it.

Although the name of the person after whom the unit is named is Ohm, which
is a proper noun and takes an initial capital, the SI unit is not a proper
noun and is named ohm, with a lowercase 'o'. So, the confusion is less
likely to arise: your example is 1ohm, which is not likely to be misread as
ten hm.
Click to expand...
I understand your argument. I was either confused by:
1) In latex the code for the ohm symbol is \Omega
2) Ohm is not one of the base units in SI but a derived one (V/A) just
like Hz (1/s) which is named after Mr. Hertz has a capital H even inside
the unit (MHz, GHz, kHz)
3) The table of formulas that I have ready is printed in Germany and
write ohm with capital O

If I don't recall wrong, it is so that the units named after their
inventor start with a capital letter, I name: Ampere (A), Henry (H),
Coulomb (C), Watt (W), Newton (N), Tesla (T), Siemens (S), Volta (V),
Weber (Vb), Farad (F), Joule (J), Kelvin (K)

The case about ohm/Ohm is a bit special since it is the greek letter
Omega which is the unit sign and not a letter from the latin alphabet,
but it is the *capital* greek letter omega, so it is probably an
academic question if you then should write 1kohm or 1kOhm or 1kOmega

--
Svenn
 
Svenn Are Bjerkem wrote:

If I don't recall wrong, it is so that the units named after their
inventor start with a capital letter, I name: Ampere (A), Henry (H),
Coulomb (C), Watt (W), Newton (N), Tesla (T), Siemens (S), Volta (V),
Weber (Vb), Farad (F), Joule (J), Kelvin (K)
Click to expand...
.... an so is Ohm:


The case about ohm/Ohm is a bit special since it is the greek letter
Omega which is the unit sign and not a letter from the latin alphabet,
but it is the *capital* greek letter omega, so it is probably an
academic question if you then should write 1kohm or 1kOhm or 1kOmega
Click to expand...
http://en.wikipedia.org/wiki/Georg_Ohm
 
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