Use peak detection to locate fiber spectra in a LRS2 image.

% 
% lmap_peaker -h 

usage: lmap_peaker FrameNum [-v] [-h] [-F font] [-c color]
arg1 = ds9 frame number (usually 1 or 3) 
Additional options: 
  -h  = just show usage message  
  -v  = run in verbose/debug mode 
  -p  = display a plot of the fiber positions 
  -c  = specify name of a configuration file 
  -cl = list and explain recognized config file parameter 

% cat s.1 
color      yellow  
font       27
YsigMIN    3500
YsigMAX    45600    

% lmap_peaker 1 -c s.1             # assumes the Frame.1 file is present 

% cat Frame.1           
 Upper  180

% cat Name.Upper           
/media/sco/DataDisk1/sco/AD/HET_work/HET_acm+lrs2/HET_IZw136/20200529/lrs2/lrs20000019/exp01/lrs2/20200529T230158.3_066LU_flt.fits

# To make a plot during the run 
% lmap_peaker 1 -c s.1 -p        

# To use only default parameter values  
% lmap_peaker 1 

Here is an example of the file created: 
% ls 
20200529T230158.3_066LU_flt_1000_peaks.params  20200529T230158.3_066LU_flt.fits  fiber_peaks.png  Name.Upper
20200529T230158.3_066LU_flt_1000_peaks.parlab  20200529T230158.3_066LU_flt.Info  Frame.1	  README
20200529T230158.3_066LU_flt_1000_peaks.reg     BaseDir				 Frame.3	  S/
20200529T230158.3_066LU_flt_1000_peaks.table   Date				 Name.Lower	  s.1

An example of the fiber peak locations derived in a run if lmap_peaker. The region file made in the run has had the color of text and marker set in the configuration file. The width of the marker (wid=4) and the size of the font are presently hard-coded in the python xymake_circles_bold.py code that builds the region file. Remember that the numbers plotted are not the LRS2 IFU fiber numbers, but rather are the integers assigned as each peak is detected. The fiber numbers are assigned by downstream software that takes into account the device (channel+amp) being analyzed by lmap.