Task: zeesim Purpose: Test reliability of Zeeman splitting errors Categories: profile analysis Estimate the reliability of Zeeman error estimates for spatial summing or averaging. This is generally essential for spatial summing, and possibly needed for spatial averaging when eta is of the order of unity. Program in four logical sections 1) Read in data 2) Fit data and get estimates of noise free spectra 3) Find the FFT of the beam 4) Simulate by adding correlated noise and refitting Key: iin Input I cube (vxy order). Wild card expansion supported. No default. Key: vin Input V cube (vxy order). Wild card expansion supported. No default. Key: beam The beam of the observation. Wild card expansion supported. Not needed for AVEOP='a' Key: mode This is a character string that determines the algorithm used in the fitting process. It consists of several flags, which can be: m Use maximum likelihood technique. l Include a leakage term in the fitting. 2 Use a two sided derivative estimate. x Perform extra checks for better solutions when using the maximum likelihood technique. d Debiased least squares estimate. The default is ' ' i.e., least squares and 1. Key: aveop 'a' for averaged spectrum in window, 's' for summed spectra. Summed computational load is orders of magnitude greater than for averaged spectra. 'h' for hybrid of averaging and summing. Default is 'a'. The hybrid is the same as 's', except when fitting the simulated spectra, whereupon the spectra are first averaged for each window. Key: chan Channel range. Default is all channels. Key: freq Frequency (GHz) for conversion of channel splitting to B field. Key: blc Bottom left corner of spatial region to examine. Default is (1,1). Key: trc Top right corner of spatial region to examine. Default is all of image. Key: bin Binning widths for all three (v,x,y) dimensions. Default = 1. This keyword enables each region (spectral and spatial) to be binned up before fitting. It's as if you had observed with lower resolution. Spatial binning is of no use if you are using spatial averaging. Key: split Splitting (split to unsplit in channels) to use for calculation of hatV and all simulation (i.e., don't use actual splitting as predicted by fitting algorithm when generating V spectra. Key: nruns The number of simulation runs to undertake. If 0, then just the initial fits are done. Default is 0. Key: infile File containing a list of windows. If this file specified, blc and trc are ignored. Should be in format: NWIN I XCEN YCEN XOFF YOFF And there are nwin of these lines. XOFF and YOFF define the box half-sizes from their specified centres, XCEN and YCEN. You can leave off XOFF and YOFF and they will default to 2 All units are pixels. Key: log If NRUNS = 0 One value which is a root file name, appended to which is the box number as specified in the INFILE (or = 1 for a box specified with BLC and TRC). These files contain the fitted results for each window. The files are opened in APPEND mode. If NRUNS > 0 Two values. The first is a root file name, appended to which is the box number as specified in the INFILE (or = 1 for a box specified with BLC and TRC). These files contain the results for each simulation with a cumulative fiddle factor worked out. The first line is the initially fit results before simulation. The second value is a file containing a statistical summary of the final results of the simulations from all windows, including the initially fit results before simulation began. Key: nran Throw away NRAN random numbers before starting. Use this to continue a set of simulations with different random numbers. Revision: 1.3, 2011/10/05 06:24:26 UTC

Generated by miriad@atnf.csiro.au on 21 Jun 2016