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yaxis = slope * xaxis + intercept D(yaxis) = slope * D(xaxis) + interceptwhere D() is the difference between succesive samples, xaxis, yaxis are the uv variables from single uvfiles. In addition, VARFIT provides an option of regression for the phases derived from the gains of two uvfiles and plots both phase-phase diagram and phase residual vs UT time. If either axis is an antenna gain, then SELFCAL must be run first and the axes are sampled at the interval used in SELFCAL. For linear regression between the two phase solutions, the setup in the SELFCAL for the two simultaneously sampled data files needs identical. The rms and correlation coefficient are listed for each antenna.

*vis*- The input UV dataset name. The antenna gains must first be derived for the selected linetype by the task SELFCAL with the desired averaging interval.
*xaxis*- xaxis can be antenna gain ``amplitude'' or ``phase'', or any uv-variables. The default is ``time''.
*yaxis*- yaxis can be antenna gain ``amplitude'' or ``phase'', or any uv-variables. The default is ``phase''.
*log*- Output log file. Default is the terminal.
*device*- Standard PGPLOT device, if plot of yaxis versus xaxis is wanted. Default is no plot.
*nxy*- Number of plots in the x and y directions. The default is 3,3.
*xrange*- The min and max range along the x axis of the plots. The default is to autoscale. Note that for "time" should be given in days.
*yrange*- The min and max range along the y axis of the plots. The default is to autoscale. Note that for "time" should be given in days.
*refant*- Reference antenna for gains and uv-variables. If refant.ne.0 then the gain of this antenna is set to cmplx(1.,0.). The other antenna gains are then relative to the reference antenna. The uv-variable value for the refant is subtracted from each of the other antennas. Single valued variables, e.g. time, are unchanged. The default is to use the original gains and uv-variable values.
*refant2*-
Reference antenna for cross correlation of gains and uv-variables.
Compare the gains or uv-variables between antennas by fitting
yaxis = slope * xaxis(refant2) + intercept D(yaxis) = slope * D(xaxis(refant2)) + intercept

where D() is the difference between succesive samples. *phratio*- Phase ratio (phase2/phase1) for slope input from users, which is used for adding a line with an expected-phase-slope in phase-phase linear regression plot when options=uniscale. Default is 0.
*nsigma*- Number of sigmas specified by users to reject 'bad gains' (or uncorrelated gains between receiver 2 and receiver 1) in the linear regression between phase2 and phase1. The sigma here is the uncertainty in the mean of the residual phase which is the phase2 subtracted by the phase determined from the initial fitting assuming the slope = freq2/freq1 in the linear regression between phase2 and phase1. It must be positive. nsigma = 4 is recommended. Default is 0, which means that no data rejection is performed.
*options*-
wrap Do not unwrap phase.
xscale Re-scale xaxis = slope * xaxis + offset, where slope
and offset are fitted w.r.t. xaxis(refant) The fit is written into the log file. E.g. yaxis=phase xaxis=tpower refant=4 log=tpscale results can be used in the task tpgains to correct tpower to a common Tsys scale.

yscale Re-scale yaxis = slope * yaxis + offset, where slopeand offset are fitted w.r.t. yaxis(refant)

structure Replace yaxis with it's structure function:<{yaxis(i+k) - yaxis(i)}**2>

allan Replace yaxis with it's Allan variance:<{yaxis(i+2k) - 2*yaxis(i+k) + yaxis(i)}**2>

quad Fit yaxis = a + b*xaxis + c*xaxis**2where a and b are first derived from a linear fit. The fit is written into the log file. E.g. yaxis=tpower xaxis=tpower refant2=4 options=quad results can be used in the task tpgains to correct tpower to a common Tsys scale.

uniscale use the maximum ranges in x and y axiesto make uniformly-scaled plots for each of the antennas.

phareg do linear regression between phase1 and phase2 derivedfrom the gain tables in uvfile1 and uvfile2, respectively. plot a solid line: phase2 = slope * phase1 + offset with the raw phase corrections in the phase/phase diagram.

phatran transfer phase2 from phase1 using the linear correlationderived: phase2 = slope * phase1 + offset and using the transferred phase2 replaces the phases in the gain table of file2.

gflag excluding the failed gains in the phase regression. tambient do linear regression between the residual phase(phase2-(slope * phase1 + offset)) and a variable tambient which is antenna-based variable and stored elsewehere (for example, SMA Sybase). The data of tambient must be stored in a ASCII file (tambient.dat) under the miriad working area in the following format: 2005 2 18 8 RM_AMBIENTLOAD_TEMPERATURE_F 1 1439 tmp1.dat 0 1.437269e+01 1 1.437269e+01 2 1.437269e+01 ... 2 1439 tmp2.dat 0 1.519706e+01 1 1.519706e+01 2 1.547185e+01 ... 1st row is year,month,day,number of antenna,RM variable followed by concatenated individual antenna files. in each antenna section, 1st row is the antenna ID; 2nd row is number of total data points and filename; 3rd and larger number rows contains the body of the data: 1st column is ut time in minute; 2nd column is the RM Variable. For the SMA users, a C-shell script (TambSybase.csh) is provided under $MIR/examples, which can be used to extract the data from SMA sybase on the computer d2o.sma.hawaii.edu at the SMA site in Hawaii.

- NAME
- PERSON RESPONSIBLE
- CATEGORIES
- DESCRIPTION
- PARAMETERS

This document was created by man2html, using the manual pages.

Time: 18:35:39 GMT, July 05, 2011