3.8. - Reciprocal Space Macros
The following macros are general and applicable to most geometry configurations. Macros special to the four-circle geometry configuration are described in the Four-Circle Reference that follows this guide.
ca H K L # Display calculated positions for H K L cal H K L # As above, but don't reset positions ci tth th chi phi # Display calculated H K L for angles br H K L # Move to H K L mk H K L # Move to H K L ubr H K L # Move to H K L while updating screen umk H K L # Move to H K L while updating screen mi ALPHA BETA # Move to ALPHA BETA wh # Display H, K, L, tth, th, chi, phi, etc. pa # Display geometry parameters
The difference between
ca and
cal is that the first macro restores the
A[] angles and
H, K and
L to the current diffractometer position, while the second
macro leaves them
at the calculated values.
There is no difference between the
br and
mk macros,
except their names.
The
ubr and
umk macros continuously read the motor positions
from the controller and show the positions on the screen.
The frequency of updates is set by the global variable
UPDATE. # Go to a Bragg position
def br '_br $*; move_poll'
def _br '
if ($# != 3) {
print "Usage: br H K L"
exit
}
waitmove; { H=$1; K=$2; L=$3 } getangles; calcA
onp; offt; printf("\nbr %g %g %g\n", H, K, L); offp; ont
move_em
'
# Calculate motor positions for a given H, K, and L
def cal '
if ($# != 3) {
print "Usage: cal H K L"
exit
} ;
{H = $1; K = $2; L = $3 } calcA; calcHKL
onp
printf("\nCalculated Positions:\n")
_var
offp
'
# As above but reset positions to diffractometer positions
def ca '
if ($# != 3) {
print "Usage: ca H K L"
exit
} ;
{H = $1; K = $2; L = $3 } calcA; calcHKL
onp
printf("\nCalculated Positions:\n")
_var
offp
waitmove; getangles; calcHKL
'
# Where - reciprocal and real space
def wh '
waitmove; getangles; calcHKL
onp
_var
offp
'
# A macro called by "wh", "ca" and "ci" to display important
# geometry quantities. (Four-circle version.)
def _var '
printf("\nH K L = %.5g %.5g %.5g\n", H, K, L)
printf("ALPHA = %.5g BETA = %.5g", ALPHA, BETA)
printf(" AZIMUTH = %.5g LAMBDA = %g\n\n", AZIMUTH, LAMBDA)
_mot 4
'