(Fwd) Standard coordinate system

['Zhong Ren' <renz@cheetah.uchicago.edu>]

--- Forwarded mail from mooney@aps.anl.gov (Tim Mooney)

Date: Fri, 13 Feb 1998 17:55:14 -0600
From: mooney@aps.anl.gov (Tim Mooney)
To: beamline_controls@aps.anl.gov
Subject: Standard coordinate system

Dear folks,

Should we agree on a standard coordinate system for beamline software?

I've been using the system that seems most common in XFD and ASD documentation:
+Z is the beam direction, +Y is up, and +X is out from the storage ring, making
a right-handed coordinate system, but to my recollection the beamline-controls
collaboration has never actually made a choice.  Now would probably be a good
time to do this, because most of us are far enough along to that it's beginning
to matter.

I was using into the storage ring as +X and down as +Y because that is the
coordinate system for most detectors readout/scanners.


Also, should we agree on the beam direction assumed in GUI displays?

As most users view their hardware, the beam goes from right to left, yet many
people
seem to prefer left to right in graphical displays.  I think relatively few
people
care deeply about this, but it is irksome to have some displays going one way
and
other displays going the other.

I vote for beam direction from left to right.


1) What beamline coordinate system does your CAT use?

2) What is the beam direction in your CAT's user displays?


Tim Mooney


---End of forwarded mail from mooney@aps.anl.gov (Tim Mooney)