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#28850 - 12/05/11 01:56 PM coor axis veriables
adi Offline
Forum Member

Registered: 10/30/09
Posts: 54
When using coor axis command within coorman.doc,
The AXIS command sets the variables XAXIs, YAXIs, ZAXIs, RAXIs, XCEN, YCEN, and ZCEN, which may be accessed with the "?" symbol.

Accessing variables or commands in Charmm requires first four letters. If more than four letters are written, CHARMm would normally ignore letters after forth.

But for above variables set by coor axis, if more than forth letters are written in command line, CHARMm does not access the set value of variable.

For ex.
RAXIs can be accessed through ?RAXI but not with ?RAXIs

This does not cause any problem as all the variables can still be accessed through proper way of writing firth four letters.
But many times writing CHARMm script, user tend to write full word just to quickly understand the meaning of the command.
In case of accessing variables set by coor axis, it does not work and user have to stick to four letter format.

This may not be a bug in itself. But if there is a quick and effortless fix to it, I would like to know.



#28851 - 12/05/11 02:25 PM Re: coor axis veriables [Re: adi]
lennart Online   content

Forum Member

Registered: 09/25/03
Posts: 4720
Loc: ~ 59N, 15E
The four-letter "rule" does not apply to variables. They are recognized by an exact match. There is no fix planned for this since it is not a bug.
If you are using CHARMm you may want to approach Accelrys support with your request.
Lennart Nilsson
Karolinska Institutet
Stockholm, Sweden

#28852 - 12/05/11 02:36 PM Re: coor axis veriables [Re: adi]
rmv Online   content

Forum Member

Registered: 09/17/03
Posts: 8334
Loc: 39 03 48 N, 77 06 54 W
It's more of a documentation bug in corman.doc; the trailing letter 's' should probably be omitted. The rules for ? variables do not seem to be the same as those for commands; if you look in subst.doc you'll find a fair number of them use more than 4 chars, and that the trailing 's' is omitted for 'XAXI' etc.

Although 4 chars is the general rule, there are some command keywords that require less than 3 chars, and I also think there may be a few keywords that require more than 4 chars.
Rick Venable
computational chemist


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