AIPS HELP file for CCNTR in 31DEC22
As of Thu Mar 23 8:20:04 2023
CCNTR: generate a contour plot with stars or fit sources marked
USERID -32000.0 32000.0 User ID. ignored
INNAME Image name(name).
INCLASS Image name(class).
INSEQ 0.0 9999.0 Image name(seq. #). 0=>high
INDISK 0.0 9.0 Disk drive #. 0=>any
BLC 0.0 4096.0 Bottom left corner of image
TRC 0.0 4096.0 Top right corner of image
XYRATIO 0.0 10.0 X to Y axis plot ratio. 0=>
header inc or window ratio
LTYPE -410.0 410.0 Type of labeling: 1 border,
2 no ticks, 3 standard, 4 rel
to center, 5 rel to subim cen
6 pixels, 7-10 as 3-6 with
only tick labels
<0 -> no date/time
PLEV -99.0 100.0 Percent of peak for levs.
CLEV Absolute value for levs
(used only if PLEV = 0).
LEVS -9999.0 99999.0 Contour levels (up to 30).
DOCIRCLE -1.0 1.0 > 0 => extend ticks to form
INEXT 'ST','CC','MF' to plot points
INVERS 0.0 46655.0 ST,CC,MF file version number
CTYPE 0.0 (1) Plot symbol # for CC, MF
(2) Number components
(3,4) Flux range for plot
symbol range 0 - CTYPE(1)
CUTOFF Only plot CCs above this flux
FLUX 0.0 Scale CCs relative to FLUX
0 -> no scaling
STFACTOR -9999.0 9999.0 Scale star sizes: 0 => none.
> 0 crosses with no labels
< 0 crosses with labels
DOTV -1.0 1.0 > 0 Do plot on the TV, else
make a plot file
GRCHAN 0.0 8.0 Graphics channel 0 => 1.
TVCORN 0.0 2048.0 TV pixel location of bottom
left corner of image 0=> self
scale, non 0 => pixel scale.
Use: CCNTR will write commands to a plot file for the execution of a
contour plot for an image. CCNTR supports TELL operations QUIT
and ABOR only. CCNTR is identical to CNTR, except that
positions and sizes of ST, CC, or MF components can be plotted.
USERID......The ID of the owner of the image. Ignored.
INNAME......Image name (name). Standard defaults.
INCLASS.....Image name (class). Standard defaults.
INSEQ.......Image name (seq. #). 0 => highest.
INDISK......Disk unit #. 0 => any.
BLC.........Bottom Left Corner of image to contour.
(0,0) means (1,1).
TRC.........Top Right Corner of image to contour.
(0,0) means top right corner of map.
XYRATIO.....The ratio of the X-axis to Y-axis pixel
separations. 0 => X to Y inc. in map header
if related, else Y to X window
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.
PLEV........Percent of peak for the contour increment. If
PLEV and CLEV are zero, 10 is used.
CLEV........Image intensity value for the contour increment.
Used only if PLEV = 0.
LEVS........Contour levels in units of the increment. The
levels must be in ascending order and a maximum
of 30 levels are permitted. 0 => -10,-9,
DOCIRCLE....False (<= 0) means that tick marks are short lines
extending inward from the plot borders. True (>0)
requests that a full coordinate grid be drawn.
INEXT.......If 'CC' plot positions (and sizes if given) of
clean components. If 'ST' plot star positions
as plus signs. If 'MF' plot positions (and sizes
if given) of model fit components.
INVERS......Version number of CC, MF, or ST (star position).
0 => highest.
CTYPE.......(1) Plot symbol number to use when plotting CC
or MF points
(2) Maximum number of CC or MF points to plot
(3,4) If CTYPE(4) > CTYPE(3), then use plot
symbols 0 to CTYPE(1) over the component flux
range CTYPE(3) to CTYPE(4). < CTYPE(3) use 0,
> CTYPE(4) use CTYPE(1).
Types supported are
0: Cross 10: Five pointed star
1: Ellipse 11: Star of David
2: Box 12: Seven pointed star
3: Triangle 13: Eight pointed star
4: Diamond 14: Nine pointed star
5: Pentagon 15: Ten pointed star
6: Hexagon 16: 11 pointed star
7: Septagon 17: 12 pointed star
8: Octagon 18: 13 pointed star
9: Nine-gon 19: 14 pointed star
20: Cross with gap >20: Ellipse
CUTOFF......Plot only components above cutoff Jy in absolute value.
FLUX........If > 0, scale each plot symbol by the current value
divided by FLUX and then multiply by STFACTOR. Applies
only to CCs.
STFACTOR....Scale factor used to multiply star or component
sizes in file for plotting.
> 0 => scale star size
= 0 => don't plot stars.
< 0 => scale by abs(STFACTOR) and show any
star label, component #.
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.
0 => use multiple graphics planes for the various parts
of the graphical drawing.
TVCORN......TV pixel location (X,Y) where the bottom left-
corner of the plot is to be placed. If either is
zero, use the largest possible self scaling, else
use pixel scaling with specified origin on the TV.
CCNTR: Task to create a contour-plot extension file for an image
RELATED PROGRAMS: CNTR, KNTR, PCNTR, LWPLA, TKPL, TVPL, TVWIN
CCNTR generates a plot extension file containing an
intensity contour plot, its border, and labels. The window
limits and contour levels are recorded in the header of the plot
file, and may be listed on your terminal with EXTLIST. CCNTR
indicates positive and negative contour values by continuous and
broken lines, respectively.
The plot itself may be displayed on a printer, TEK screen,
or TV graphics channel by the tasks TXPL and LWPLA, TKPL, or TVPL
It differs from CNTR in the option to overplot symbols at
the location of components in the CC file.
Contour plots are often more useful for quantitative image
analysis than gray-scale or profile plots, and most maps are
published in the form of contour plots. By suitable choice of
contour levels, a contour plot can give a quantitative display
of all features in an image with very large dynamic range. The
contour plot of a map will be messy if contours are plotted at
levels below about 3 times the rms noise.
Contour plots tend to emphasize gradients in intensity. The
contour plot of a complex image, especially one with local
minima, can therefore be confusing. Note that a local (but
non-negative) minimum will be indicated by a closed continuous
contour, so that it is indistinguishable from a maximum. Also,
the simple interpolation routine used by CNTR may produce jagged
"staircase" contours. This problem can be minimized by
interpolating the image with the task GEOM.
A convenient way to select the plot corners is to display
the image on the TV and set the rectangular boundary of the
subimage to be plotted with the verb TVWIN.
Nonzero elements LEVS(I) in this 30-element vector
specify the contour levels LEVS(I)*PLEV or LEVS(I)*CLEV to be
plotted. They must be specified in increasing order and lie
within the range -9999.0 to +99999.0. It is easy to specify a
large number of LEVS values with a FOR loop. For example,
FOR I=1 TO 20;LEVS(I)=2**((I-1)/2.);END ; LEVS(21)=0.
yields successive contours separated by factors of 2**.5
If you request more than one negative level via a statement
of the form
LEVS = a , b , c , d , e , f , g
you must use commas between the negative levels. Otherwise, the
minus sign(s) will be treated as subtraction symbols by POPS and
the desired levels will be combined into a single negative
1=> unlabeled rectangular border
2=> rectangular border plus labels (image name, center
position, etc.). Beware that the PEAK FLUX label
gives the peak flux in the whole image, not that in
the subimage plotted.
3=> rectangular border, labels, and border tick marks
indicating absolute coordinates (r.a., decl., etc.)
4=> rectangular border, labels, and border tick marks
indicating coordinates relative to the coordinates
of the image reference pixel
5=> rectangular border, labels, and border tick marks
indicating coordinates relative to the center of
the subimage plotted
6=> rectangular border, labels, and border tick marks
indicating image pixel numbers
7-10 => like 3-6 but the extra labels are omitted.
An LTYPE which is < 0 is used, in absolute value, to
control the labeling as listed above and specifies that
the "PLOT FILE VERSION n CREATED date time" string is
not placed on the plot.
XYRATIO can be used to change the plot aspect ratio.
Values >1 stretch the X-axis, values <1 compress it.
DISPLAYING THE PLOT:
On termination of CNTR, the messiness of the plot can be
judged by looking at the message on your monitor:
GFINIS: NUMBER OF RECORDS GUESSED NNN USED MMM
If MMM is much greater than 200, the plot will be complicated.
If this happens when you thought you were contouring a simple
small field, you have probably set the levels too low (or have
specified the contouring window incorrectly). You may wish to
check your inputs before trying to display the plot. It is
always worth using TKPL or TVPL to preview a new plot before
routing it to the slower LWPLA, unless you are very sure that
your input parameters were well chosen.
In an otherwise empty VAX 11/780 a plot of 10 or so
contours in a 100 by 100 window with a straightforward source
takes about 20 seconds. Large, messy, or noise-limited plots
may take many minutes. If CNTR seems to be taking longer than
expected, you may be plotting more contours than you wanted.