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WATCH

A beam property/motion monitor-allowed modes are centroid, parameter, coordinate, and fft.
Parallel capable? : yes
Parameter Name Units Type Default Description
FRACTION   double 1 fraction of particles to dump (coordinate mode)
INTERVAL   long 1 interval for data output (in turns)
START_PASS   long 0 pass on which to start
END_PASS   long -1 pass on which to end (inclusive). Ignored if negative.
FILENAME   STRING   output filename, possibly incomplete (see below)
LABEL   STRING   output label
MODE   STRING coordinates coordinate, parameter, centroid, or fft. For fft mode, you may add a space and a qualifer giving the window type: hanning (default), parzen, welch, or uniform.
X_DATA   long 1 include x data in coordinate mode?
Y_DATA   long 1 include y data in coordinate mode?
LONGIT_DATA   long 1 include longitudinal data in coordinate mode?
EXCLUDE_SLOPES   long 0 exclude slopes in coordinate mode?
FLUSH_INTERVAL   long 100 file flushing interval (parameter or centroid mode)
DISABLE   long 0 If nonzero, no output will be generated.
USE_DISCONNECT   long 0 If nonzero, files are disconnected between each write operation. May be useful for parallel operation. Ignored otherwise.
INDEX_OFFSET   long 0 Offset for file indices for sequential file naming.
GROUP   string NULL Optionally used to assign an element to a group, with a user-defined name. Group names will appear in the parameter output file in the column ElementGroup





The output filename may be an incomplete filename. In the case of the WATCH point element, this means it may contain one instance of the string format specification ``%s'' and one occurence of an integer format specification (e.g., ``%ld''). elegant will replace the format with the rootname (see run_setup) and the latter with the element's occurrence number. For example, suppose you had a repetitive lattice defined as follows:

W1: WATCH,FILENAME=''%s-%03ld.w1''
Q1: QUAD,L=0.1,K1=1
D: DRIFT,L=1
Q2: QUAD,L=0.1,K1=-1
CELL: LINE=(W1,Q1,D,2*Q2,D,Q1)
BL: LINE=(100*CELL)
The element W1 appears 100 times. Each instance will result in a new file being produced. Successive instances have names like ``rootname-001.w1'', ``rootname-002.w1'', ``rootname-003.w1'', and so on up to ``rootname-100.w1''. (If instead of ``%03ld'' you used ``%ld'', the names would be ``rootname-1.w1'', ``rootname-2.w1'', etc. up to ``rootname-100.w1''. This is generally not as convenient as the names don't sort into occurrence order.)

The files can easily be plotted together, as in

% sddsplot -column=t,p *-???.w1 -graph=dot -separate 
They may also be combined into a single file, as in
% sddscombine *-???.w1 all.w1 

In passing, note that if W1 was defined as

W1: WATCH,FILENAME=''%s.w1''
or
W1: WATCH,FILENAME=''output.w1''
only a single file would be produced, containing output from the last instance only.

N.B.: confusion sometimes occurs about some of the quantities related to the s coordinate in this file when in parameter mode. Please see Section 4 above.


next up previous
Next: WIGGLER Up: Element Dictionary Previous: WAKE
Robert Soliday 2014-06-26