AIPS HELP file for SNFIT in 31DEC25
As of Tue Dec 10 5:32:18 2024
SNFIT: Task to fit parabolas or 4th order to SN amplitudes
INPUTS
INNAME UV data (name).
INCLASS UV data (class).
INSEQ 0.0 9999.0 UV data (seq. #). 0 => high
INDISK 0.0 9.0 Disk unit #. 0 => any
INVERS Input table file version no.
SOURCES Source list
QUAL -10.0 Source qualifier -1=>all
TIMERANG Time range to plot
STOKES Stokes type to plot: R, L,
RR, LL, RRLL, DIFF, RATO
V, H, VV, HH, VVHH
SELBAND Bandwidth to plot (kHz)
SELFREQ Frequency to plot (MHz)
FREQID Freq. ID to plot, -1=>all
SUBARRAY -1.0 Limit to subarray; 0 -> 1
-1 -> all
BIF 0.0 100.0 First IF to plot, 0=>1.
EIF 0.0 100.0 Last IF to plot 0 -> highest
ANTENNAS Antennas to plot 0=>all
PIXRANGE Range to plot: 0 => self
scale each antenna separately
NPLOTS 0.0 28.0 Number of plots per page
XINC 0.0 5000.0 Plot every XINC'th point
OPTYPE Data to be plotted:
'AMP ','POWR','PODB'
' '='PODB'
APARM (1) Min value to fit
(2) Max value to fit
(3) =4 => use 4th order
function
SYMBOL 0.0 24.0 Plot symbol number: 1 - 24
FACTOR -10.0 10.0 Scale plot symbols by FACTOR
<0 => connect points too
DOBLANK -1.0 24.0 > 0, show blanked values with
symbol type DOBLANK
CUTOFF Table weights <= CUTOFF will
not be plotted, flagged data
are not plotted.
LTYPE -410.0 410.0 Type of labeling: 1 border,
2 no ticks, 3 - 6 standard,
7 - 10 only tick labels
<0 -> no date/time
DOTV -1.0 1.0 > 0 Do plot on the TV, else
make a plot file
GRCHAN 0.0 8.0 Graphics channel
OUTTEXT Not blank -> write text file
with answers
HELP SECTION
SNFIT
Type: Task
Use: Plots selected calibration data versus time from a specified SN
table and fits a 2nd order or 4th order polynomial to the gain
amplitudes (as gain, power, or power in db). This is to be
used for scans through the primary beam on strong calibration
sources. Moving sources are supported if a PO table is
attached.
Adverbs:
INNAME.....UV file name (name). Standard defaults.
INCLASS....UV file name (class). Standard defaults.
INSEQ......UV file name (seq. #). 0 => highest.
INDISK.....Disk unit #. 0 => any.
INVERS.....Version number of table to plot, 0=>highest no.
SOURCES....Source list. '*' = all; a "-" before a source name means
all except ANY source named.
QUAL.......Only sources with a source qualifier number in the SU table
matching QUAL will be used if QUAL is not -1.
TIMERANG...Time range of the data to be plotted. In order: Start day,
hour, min. sec, end day, hour, min. sec. Days relative to
reference date. If a start and stop time are given and
the XAXIS is 1 (time), then all plots will be from the
given start time to the given stop time. Otherwise, the
X-axis is plotted over the range of X values found in the
data. All plots in a given execution will be on the same
X scale in any case.
STOKES.....The desired Stokes type of the displayed data:
'R' = RCP, 'L' = LCP, 'RL' or 'RRLL' both RCP and LCP
'V' = VLP, 'H' = HLP, 'VH' or 'VVHH' both VLP and HLP
SELBAND....Bandwidth of data to be selected. If more than one IF is
present SELBAND is the width of the first IF required.
Units = kHz.
SELFREQ....Frequency of data to be selected. If more than one IF is
present SELFREQ is the frequency of the first IF required.
Units = MHz.
FREQID.....Frequency identifier to select (you may determine which is
applicable from the OPTYPE='SCAN' listing produced by
LISTR). If either SELBAND or SELFREQ are set, their values
overide that of FREQID. However, setting SELBAND and
SELFREQ may result in an ambiguity. In that case, the task
will request that you use FREQID. -1 => all, 0 => first
SUBARRAY...Limit display to specific subarray. -1 -> all, 0 -> 1.
BIF........First IF IF to plot
EIF........Last IF to plot.
If OPCODE = 'IFDF'/'IFRA' will plot difference/ratio of
specified quantity between BIF and EIF.
ANTENNAS...A list of the antennas to be plotted. All 0 => all. If any
number is negative then all antennas listed are NOT to be
plotted and all others are.
PIXRANGE...If PIXR(1) < PIXR(2), all plots will be from PIXR(1) to
PIXR(2). Otherwise each plot will be self-scaling.
NPLOTS.....Number of antennas to plot per page (try 5).
XINC.......Plot every XINC'th point, 0 => 1.
OPTYPE.....Data to be plotted:
1. 'AMP ' = amplitude,
2. 'POWR' = (1/Gain amp)^2
3. 'PODB' = Log10 (1/Gain amp)^2
other => 'PODB'
APARM......(1) Lower limit of data to be used in the fit
(2) Upper limit of data to be used in the fit
(APARM(2) <= APARM(1) -> all data are used)
(3) If APARM(3) = 4, a fourth order function is fit,
otherwise a second order function is fit.
SYMBOL.....Choices are:
1: Plus sign 13: Star of David
2: Cross (X) 14: Seven-pointed star
3: Circle 15: Eight-pointed star
4: Box 16: Nine-pointed star
5: Triangle 17: Ten-pointed star
6: Diamond 18: 11-pointed star
7: Pentagon 19: 12-pointed star
8: Hexagon 20: 13-pointed star
9: Septagon 21: 14-pointed star
10: Octagon 22: Plus (+) with gap
11: Nine-gon 23: Cross (X) with gap
12: Five pointed star 24: Vertical line
FACTOR.....Scale plot symbols by FACTOR 0 -> 1.
If FACTOR < 0, draw lines between the points and use
abs(FACTOR) to scale the points plotted.
DOBLANK....> 0 => plot blanked solutions with a symbol of type
DOBLANK (see symbol types above). They will be plotted
along the lower edge of each plot. NOTE: if DOTV true
and GRCHAN 0 and DO3COL <= 0, then the blanked samples
will be in the color of graphics channel 3 (pink) and the
good samples in the color of graphics channel 4 (blue).
DOBLANK > 0 is forced to be different than SYMBOL by
adding 1.
CUTOFF.....If >= 0, the task will examine the weight column of the
table and if the weight <= CUTOFF, the task will not plot
that sample. If = 0, will plot all good points; flagged
data are not plotted. CUTOFF is ignored for TY and PC
tables and OPTYPEs MDEL, ATM, GEO, and CCAL.
LTYPE......Labelling type, see HELP LTYPE for details:
1 = border, 2 = no ticks, 3 or 7 = standard, 4 or 8 =
relative to ref. pixel, 5 or 9 = relative to subimage
(BLC, TRC) center, 6 or 10 = pixels. 7-10 all labels
other than tick numbers and axis type are omitted.
Less than 0 is the same except that the plot file
version number and create time are omitted.
Add n * 100 to alter the metric scaling.
DOTV.......> 0 => plot directly on the TV device, otherwise make a
plot file for later display on one or more devices
(including the TV if desired).
GRCHAN.....Graphics channel (1 - 7) to use for line drawing.
A value of 0 causes more than one graphics channel to be
used.
OUTTEXT....If not ' ', write the fit values to a text file.
EXPLAIN SECTION