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smagpplt

Section: User Commands (1)
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NAME

smagpplt - Plot,smooth and fit to gain and bandpass.  

PERSON RESPONSIBLE

jhz  

CATEGORIES

calibration  

DESCRIPTION

SmaGpPlt is a MIRIAD task which plots and lists antenna gain and bandbass. The plot for gains is against time. The plot for bandpass is against the frequency. SmaGpPlt provides options to moving smooth or orthogal polynomial fit to the gain/bandpass solutions and to over write the old gain/bandpass tables with the smoothed or polynomial fit results. In addition, SmaGpPlt allows to compare bandpass solutions in two vis files. SmaGpPlt can also merge two gain tables computed (using either SmaMfCal or MfCal from two calibrators that were observed interleavely.  

PARAMETERS

vis
The name of the input data-set. This will normally be a visibility data-set. No default. If two files are given, options must be either 'bandpass' or 'gains,merge'.
device
The PGPLOT plotting device to use. The default is no plot.
log
The log to give a listing of the gains and polarization terms. The default is no log.
xaxis
This specifies the variable of the x-axis in plot when options is given as 'bandpass':
  chan     Plot/list channels.
  freq     Plot/list frequencies.
If nothing is given, 'freq' is assumed. For options=gains, only time (UT) of x-axis is supported.
yaxis
This specifies what is to be plotted/listed. Several values can be given, separated by commas. Minimum match is used:
  amp      Plot/list amplitudes. This is the default if the gains
           are being plotted/listed, and nothing else is requested.
  phase    Plot/list phases.
  real     Plot/list the real parts. This is the default if the
           polarization terms are being plotted/listed, and nothing
           else is requested.
  imag     Plot/list the imaginary parts.
If nothing is given, 'amp' is assumed.
options
Some extra processing options can be given. Several values can be given, separated by commas. Minimum match us used.
  gains        Plot/list the gains vs time. This is the default if
               nothing else is requested.
  bandpass     Plot/list the bandpass shape vs frequency.
  dots         Plot things as dots (rather than chunky circles).
  dtime        Give time in days and fractions of a day. This is more
               useful for listing files which are to be passed into
               some other analysis or plotting tool.
  wrap         Don't unwrap phase plots.
  msmooth      Do moving average of the bandpass/gain curve using 
               the smooth parameters and replace old one.
  weight       This gives weight in the orthogonal polynomial
               least-square fit to the antenna gain 
               curves.

               <1  => weight = 1, uniform weight.
                1 or greater  => weight = the sqaure of amplitude
                  of 1/g, where g is a complex antenna gain
                  derived within a solutional interval.
               The default is 1.

  opolyfit     Do least-square fit to the bandpass/gain curves 
               with an orthogonal polynomial of degree n and replace 
               old one. Only one of the options is allowed in 
               the replacement of the gain/bandpass. Please choose
               either msmooth or opolyfit.
  ratio        do ratio (bp1/bp2) in comparison of two bandpasse
               solutions if Keyword vis is given two input vis files. 
               The default is to compare the difference (bp2-bp1).
  merge        merge two gain tables associated with the two
               visibility files respectively. Two input vis
               files must be given. The merged gain table
               will be placed in the second input vis file
               by overwritting on the old gain table.
  xpass        transfers the bandpass solution from the image
               side band (1st input file) to the target side
               band (the 2nd input file) by reversing
               the channel sequence of the solutions while 
               the frequency tables are kept unchanged.
               vis must be given by two files containing
               'bandpass' and 'freqs' produced from the
               image bands (chunks) of the opposite
               sidebands. 
  nofit        does not display polynomial fitting or
               moving smooth curves on the gains/bandpass
               solution plots. 
filelabel
This gives an option to label the file name in the plot:
 filelabel = -1, not to label the file name, the default;
 filelabel =  0, label the file name to each of panel plots;
 filelabel =  1, label the file name to the 1st panel in
              the case of multiple panels.
smooth
This gives three parameters of moving smooth calculation of the bandpass/gain curves smooth(1) = K parameter k giving the length 2k+1 of the averaging
               interval; default is 3.
               If smooth(1) =0, then polynomial fit will be
               taken.
smooth(2) = L order of the averaging polynomial l; default is 3. smooth(3) = P probability P for computing the confidence limits;
               default is 0.9. 
polyfit
polyfit(1) gives a degree of orthogonal polynomial in least-sqaure fit to the bandpass/gain curves. Default is 0 (moving smooth). If polyfit(1)=0, then the moving average is taken. If polyfit(2)>0, then the Chi-square parameters as function of a polynomial order 1 (linear) , 2 (parabolic), 3 (cubic), 4, 5 are reported for each antenna and each spectral window. The minimum Chi-square corresponds to the best fit in orthogonal polynomial regression.
nxy
Number of plots in the x and y directions. The default is 2,2.
select
A subset of the normal uv-selection parameters. They are not entirely consisently used. Antenna and time selection is supported for gains. Time selection is supported for delay and spectral correction. Antenna and frequency selection is supported for bandpasses. The default is to select everything.
yrange
The min and max range along the y axis of the plots. By default gpplt autoscales. If the ``yrange'' parameter is given, then this range is used on ALL plots. So it may not make much sense to plot different sorts of quantities (e.g. amplitude and phases) when explicitly giving the plot range.
dotsize
Allows users to choose a symbol (dot) size in a range between 1-201. The actual plotted dot size depends on the device resolution. Other internal symbol selecting function would be failed when this parameter is in use. Default is to disable this function.


 

Index

NAME
PERSON RESPONSIBLE
CATEGORIES
DESCRIPTION
PARAMETERS

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Time: 18:35:38 GMT, July 05, 2011