polpack_example

polpack_example

NOTES:
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ORAC-DR will produce individual images (for each of the pol vectors) 
labelled _I, _P, _th, etc.  It will also produce a "catalogue" file, 
.FIT: for example, gu20020101_123_I.sdf, gu20020101_123_P.sdf, 
gu20020101_123.FIT, etc.



1.  Copy files to something more meaningful...

  > cp gu20020101_123.FIT smm1.FIT
  > cp gu20020101_123_I.sdf smm1_I.sdf



2. Bin up values in the catalogue file:

  > polbin
  IN - Input catalogue /@m87j_bin/ > smm1             <<------ smm1
  BOX - Bin size /5/ > 3
  METHOD - Binning method /'mean'/ > 
  OUT - Output catalogue > smm1_bin                   <<------ smm1_bin

   320 vectors written to the output catalogue.



3. Create a "sub"-catalogue which contains only select values,
in this case for pixels where Intensity > 0 but Polarisation
percent is < 0, and polarisation is at least 3-sigma

  > catselect
  CATIN - Input catalogue: /@smm1_avcube(,,1)/ > smm1_bin
  CATOUT - Output catalogue: > smm1_thr               <<------ smm1_thr
  REJCAT - Rejects catalogue? /NO/ > 
  SELTYP - Selection type: /''/ > e
  EXPR - Selection expression: > I>0 & P/dp > 3 & P<10
    88 objects selected.



4. Display image (created by ORAC-DR) and overplot vectors:

  > display smm1_I
  MODE - Method to define the scaling limits /'per'/ > 
  PERCENTILES - Percentiles for scaling /[10,90]/ > 
  Data will be scaled from -0.0009998139 to 0.002607805.

  > lutgrey

  > polplot smm1_thr noclear frame=pixel vscale=8
  Alignment has occurred within the PIXEL Domain.
    88 vectors plotted.



5. Finally, create image from the smoothed catalogue file created earlier:

  > polimage
  IN - Input catalogue /@unpol_K_cat/ > smm1_thr
  COLDAT - Name of catalogue column holding data values /'U'/ > P
  OUT - Output image /@unpol_K_U/ > smm1_thr_P        <<------ smm1_thr_P

  COLDAT - Name of catalogue column holding data values /'ang'/ > DP
  OUT - Output image /@smm1_thr_ang/ > @smm1_thr_dP

  COLDAT - Name of catalogue column holding data values /'z'/ > ang
  OUT - Output image /@dp/ > smm1_thr_ang

  > ls *_thr*.sdf

	smm1_thr_P.sdf     smm1_thr_dP.sdf    smm4_thr_ang.sdf
	smm1_thr_ang.sdf   smm4_thr_P.sdf     smm4_thr_dP.sdf