Identifier sws_rebin Purpose Rebin an AAR onto a predefined grid or on a grid defined by a constant resolution or constant binsize Synopsis aar = sws_rebin( aar_in [, ref] [, resolution=resol] [, binsize=binsize] [, oversample=oversample] [, xrange=xrange] [, aot_number=aot_number] [, aot_speed=aot_speed] [, aot_band=aot_band] [, lines=lines] [, scan=scan] [, det=det] [, /merge] [, method=method] [, minbin=minbin] [, /nosmooth] Arguments name I/O type description -------------------------------------------------------------- aar O struct Rebinned spectrum in AAR format aar_in I struct Input AAR ref I struct Reference AAR containing an 'oversampled' wavelength grid. SWS_REBIN checks on the definition of AOT-bands, LINE and SCAN resolution I fltarr Resolution to rebin the data to. The defaults are resp. for AOT 1 speed 1/2 3 4, AOT2/AOT6 or AOT7 default. [default: 300/500/1000/1500/20000] binsize I fltarr Constant binsize to which the AAR is rebinned. Not used when RESOLUTION has a nonzero value. [No default] oversample I int Oversample the spectrum. [default: 4] xrange I fltarr Full wavelength ranges of aot-bands as in the reference aar or the data itself aot_number I int Read from the AAR header. On error AOT_NUMBER 1 is assumed. [Default: yes] aot_speed I int Determined from the header. On error AOT_SPEED 4 is assumed for AOT 1 else AOT_SPEED 0. [Default: yes] aot_band I strarr AOT-bands to rebin Specifing 'NONE' will rebin the full spectrum in one (usefull e.g. for AAR's in which the status and flag are undefined) [Default: all aot-bands] lines I intarr Lines, as defined in the AAR line tag. LINES=0 combines all lines in a band and assumes SCAN=0 [Default: all] scans I intarr Scans, as defined in the AAR scnt tag. SCAN=0 combines all scans. [Default: all] det I intarr Detectors to use. /merge I keyword The data is first rebinned for each AOT-band/line, after which ovelapping regions are averaged. method I string Method used to determine the values in the rebinned spectrum. 'FLUXCON' : flux conserving rebinning 'MEAN' : plain average rebinning 'WMEAN' : weighted mean rebinning 'MEDIAN' : median binning [default: 'FLUXCON'] weight I string Defines how the weighting for the weighted mean rebinning should be done. 's' standard deviations (1/s^2) 't' integration time (sqrt(t_int)) 'g' gaussian distribution with distance of center of bin and fwhm of res When combining options enter e.g. 'st' [default: 's'] minbin I int minimum number of points required [Default: 3] nosmooth I keyword Do not smooth the data with a gaussian of FWHM of the RESOLUTION (only relevant with the FLUXCON option) noplot I keyword Do not plot the spectrum. Returns Rebinned spectrum in the form of an AAR Description SWS_REBIN will rebin the input data onto a grid either specified by the user or to a fixed resolution or binsize. Only data not flagged as NODATA is used. For resolution bins for which there is no data a warning is issued. The values for these points are replaced by interploated values and the FLAG is set to NODATA. Default all AOT-band's, lines and scans are treated seperately. When using /MERGE all AOT-bands/lines/scans are first rebinned seperately and then combined afterwards. AOT_BAND = 'NONE' will rebin all data LINES = 0 will combine all lines and scans SCANS = 0 will combine all scans WMEAN gives a weighted average rebinned spectrum. The weighting can be a combination of three items; 's' the standard deviation (1/(stdev^2)) 't' integration time (sqrt(t_int)) 'g' gaussian smoothing (with fwhm of the resolution) The applied weight is the multiplication of the individual weights. To use this enter a combination of the characters, e.g. WEIGHT='s' (default) or WEIGHT='stg'. Adding a character more times will add its weight accordingly, e.g. WEIGHT='tt' or 'stt' will add the weight for the integration time twice making the effective weight for the integration time t_int instead of sqrt(t_int). FLUXCON implies flux conserving rebinning. For each bin the flux value is calculated using the trapezoidal rule. When using FLUXCON, the data is smoothed with a gaussian with a FWHM of the resolution. /NOSMOOTH disables this. Setting the IA error level to 'D' (debug) will give the user information on e.g. the wavelength of the bin and the number of points in the bin. Plotted is the input data for each AOT-band/line and and the rebinned spectrum. Examples It is possible to combine resolution and binsize to rebin one band to a constant resolution and another to a constant binsize, e.g: aotbands=['1a','1b','1d','1e'] resol =[2000,1500,0 ,1200] binsize =[0 ,0 ,0.003,0 ] aar_reb=sws_rebin(aar, aot_band=aotbands, $ resol=resol, binsize=binsize) Comments Category UTIL Filename sws_rebin.pro (module: sws_rebin) Version 2.9 History 1.0 08-02-1996 FL document created 1.1 06-03-1996 FL error in auto range 1.2 25-03-1996 FL range->xrange, improved in speed 02-04-1996 FL variable 'wave' replaced by 'waves' 1.3 10-05-1996 FL rebin per line/aotband, add sigma clipping and flux conserving rebinning 1.4 14-05-1996 FL proper date in history for v1.3, improved procedures 1.5 14-05-1996 FL ignore line tag, removed small bugs 1.6 15-05-1996 FL error in sigma clipping, problems with using INT_TABULATED -> call replaced 1.7 17-05-1996 FL checked plotrange, option 'none' and check on NODATA 2.0 10-06-1996 FL SIGCLIP routine extracted, Gaussian smoothing with FWHM of the res. bin. 2.1 17-06-1996 DRB not_enoug(0) -> not_enough(0) 2.2 04-07-1996 FL return noise in stdev (stdev/sqrt(no)) 2.3 19-08-1996 FL /NOSMOOTH did not work 2.4 11-09-1996 FL SPR_S0056 and SPR_S0057, better colors problems with AOT6s solved 2.5 15-09-1996 FL SPR_S0059 inproper binsize init with RESOL 2.6 28-11-1996 FL SPR_S0131 new interface to CHK_MULTIX 2.7 24-02-1997 FL SPR_S0189 correct line numbers, correct FWHM with Gaussian. 2.8 05-09-1997 FL SPR_S0268 retain reference grid, also with AOT-bands SPR_S0267 correct use of line and scnt 2.9 25-09-1997 FL SPR_S0281 more efficient data selection added WMEAN method SPR_S0282, use rgb colors