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tvimcontour xray.xplot



tvimcontour -- Load and overlay Contours of an image onto the Tv display device.


tvimcontour image units clevel map_type


Tvimcontour loads an Image and Overlays Contours onto the tv display device. The algorithm that determines the skymap is WCSLAB code developed at ST that supports the world coordinate system (WCS) of the image. The task will display full images, image sections, and rotated images with accuracy. Images displayed on the tv device must be square to have contours overlay the displayed image correctly. The image display and contours fill the display device, thus if the image is smaller or larger than the Saoimage/imtool device, the task interpolates the image to fit the display window.

Choice of Skymap or Pixel map displays are available. Other options include syntax for specification of contour levels, placement choice for labels, and grid or tic options for marking the lines of ra/dec or pixels. The graph is displayed on the Image display (imdr|y|b|g|w), and a list of source positions can be input and marked on the plot with the user's choice of markers.

Reference the imcontour and Display Help files for a more detailed description.


image = "" prompt = IRAF image filename

The image filename. This can be any valid IRAF image file, including X-ray QPOE files. WCS Parameters are read from the header, but they do not exist the default is to draw a pixel map.

map_type = "sky" prompt = Grid type (sky|pixel)

Grid Type for Contour map. Your Choices are:

        sky --- draws a scaled sky map with labeled  lines of RA
                & DEC

        pixel - draws a scaled grid with labeled pixels
units = "peak" prompt = Units (pixel|peak|sigma)

The units in which to interpret the contour levels. Your choices are:

        pixel - levels expressed as photon values

        peak -- levels expressed as  a percentage  of  the peak.
                The  peak   is the value   of  maximum number of
                photons at a pixel position in the image.

        sigma - levels  expressed in  photons  as  stored  in an
                array that is  the result of  dividing the input
                image by an associated error array.  If an error
                element has 0 stored the result is 0.
                (see the task \fIerrcreate\fR for info on how
                 to generate the error array)

clevel = "log 100 5" prompt = Contour Levels

The contour levels at which to graph the image. When display is set to 2, the list of computed levels is displayed.

Syntax "min max steps" creates steps+1 contour levels from min to max inclusive. Current maximum number of contour levels is defined as 100.

Your choices are:

        (l1, l2, l3, l4) ------ list of levels
                ex. (5.0, 10.5, 20.)

        linear min max steps -- linear function - abbreviation 'lin'
                                                  also accepted.
                ex. linear 1 100 10

        log min max steps ----- log function - if log 0 is specified
                                it is replaced with log 1 and a Warning
                                message is displayed.
                ex. log 1 100 10

        filename -------------- Ascii  file  name  with  contour
                                levels  listed  in one  of the 3
                                forms above.
                ex. clevel.lis

* All numeric values are read as reals. Decimal points, commas, and parenthesis are not required.
error_image = "" prompt = IRAF error image filename

The error image filename is optional. This can be any valid IRAF image file, including X-ray QPOE file. It must be the same size as the image file. The image is divided by the square root of the error file and the result is contoured. (Errors are stored as the errors squared in PROS and can be generated with the ERRCREATE task). If an error array element has 0 stored the result is 0.

gcolor = "r" prompt = Contour Graphics Overlay Color - r|y|b|g|w|B

The color of the Contour lines and labels to be displayed on the image device. Input r=red, y=yellow, b=blue, g=green, w=white, B=black.

(wlpars="") [pset]

The name of the parameter set (pset) containing the labelling parameters which controls the detailed appearance of the sky plot. See help wlpars for a detailed description of the parameters. If NULL ("") then the params set in wlpars will be used. The parameters are customized in one place and used by both imcontour & tvimcontour along with other sky labelling tasks.

(display = 2) [int]

The range is 0-5. The higher the number more verbose the display. Will print a few header params with low value, higher value is for debugging. Display level 2 has a moderate number of useful prints that informs the user of progress and interpretation of parameters.

(dotitle = yes) [boolean]

Yes labels the contour plot with a title. The title consists on an image title as it appears in the input file header, and the name of the plot file. No skips this option. This parameter is meant to aid the user in preparing plots for publication.

(dolegend = yes) [boolean]

Yes labels the contour plot with a legend. The legend consists of a field center and contour level display drawn along the right border. No indicates that no legend is plotted. This option is meant to aid the user in preparing plots for publication.

(src_list = "none") [string]

Optional Input Source List in table or Ascii format for marking source positions on the contour graph. When display is 2, the list of positions and computed pixel positions are displayed.

TABLE Format: Name of a table file. Optional column names for right ascension and declination. Ra/Dec Units in table are Degrees.

(racol = "ra") [string]

Right Ascension Column Name in degrees

(deccol = "dec") [string]

Declination Column Name in degrees

ASCII Format:  Input of 1 of 4 ascii list formats expected:

1) A list of RA and DEC in 2 columns with colon delimeters:
   (format: 2 columns - rh:rm:rss.s dh:dm:dss.s)

        12:56:06.8    35:45:03.6
        12:55:46.5    35:36:01.0

2) A list of RA and DEC in 3 columns with colon delimeters:
   (format: 3 columns - char_id rh:rm:rss.s dh:dm:dss.s)

        src_1 12:56:06.8    35:45:03.6
        src_2 12:55:46.5    35:36:01.0

3) A list of RA and DEC in 6 columns with space delimters:
   (format: 6 columns - rh rm rss.s dh dm dss.s)

        12 56 06.8 35 45 03.6
        12 55 46.5 35 36 1.0

4) A list of RA and DEC in 7 columns with space delimters:
   (format: 7 columns - char_id rh rm rss.s dh dm dss.s)

        src_1 12 56 06.8 35 45 03.6
        src_2 12 55 46.5 35 36 1.0
(isystem = "") [string]

Input coordinate system for Source List above. When default empty string is set the system of the input Image File is used. This can be overridden by specifying one of the systems below:

        [Equatorial] Jxxxx.xx
                        -- FK5 system with Julian equinox.
        [Equatorial] Bxxxx.xx[@xxxx.xx]
                        -- FK4 system with Besselian equinox and
                           optional Bessalian observation epoch.

        Image_name      -- Pseudo system.  The sky system of the 
			   specified image will be used for this 
(src_mark = "+#") [string]

Source marker when src_list specified. The following notation is interpreted:

        "<char>"        - mark source with specified character
                          ex. "*" will mark sources with *'s
        "#"             - mark source with a number
                          ex. "#" will mark sources 1, 2, 3 ...
        "<char>#"       - mark the source with a char and a number
                          ex. "+#" will mark sources + 1, + 2, + 3 ...
(pixgrid = "full") [string]

Indicates grid choice. Types available are:

        full - plot full grid
        tics - plot tics marks along perimeter of plot
        none - no grid or tics marks
(pixlabels = "in") [string]

Indicates where to place labels in relation to contour area. Choices are:

        in --- label axes inside the contour area
        none - no labels on plot
(pixel_lines = 10) [int]

Used if map_type = "pixel" (see above param). Estimated number of graphed pixel lines on the map in X & Y independently. Task chooses evenly spaced intervals near the input value, thus the actual number may be more or less than the parameter.

(labout = no) [bool]
Used if map_type = "sky" (see above param). No labels the graph with labels inside of the sky grid, Yes labels the graph outside of the grid borders.
(zrange = no) [bool]

If set to yes, Map the full range of the image intensity to the full range of the display. Map between z1 and z2 below if zrange=no.

(z1=0.0, z2=30.0) [real]

Minimum and maximum image intensity to be mapped to the minimum and maximum display levels.

(ztrans = "linear") [string]
Transformation of the image intensity levels to the display levels. The choices are:
   Map the minimum and maximum image intensities linearly to the 
   minimum and maximum display levels.

   Map  the  minimum  and maximum image intensities linearly to the 
   range 1 to 1000, take the logrithm (base 10),  and  then map the 
   logrithms to the display range.

   Apply no mapping of the image intensities (regardless of the 
   values of zcale, zrange, z1, and z2).  For most image displays,  
   values exceeding the maximum display value are truncated by masking 
   the highest bits.  This corresponds to applying a modulus operation
   to the intensity values and produces "wrap-around" in the display 

   User supplies a look up table of intensities and their corresponding 
   greyscale values.


File rh110267_smo is used in examples below and was created by running 
imsmooth on the qpoe file creating a 256x256 smoothed image:
	imsmooth xdata$rh110267.qp[bl=32] 


Running Tvimcontour with the Defaults:

cl> tvimcontour
IRAF image filename: rh110267_smo
Grid type (sky|pixel): sky
Units (pixel|peak|sigma) (peak): 
Contour Levels (log 5 100 5): 

... First Displays and then Plots a Contour map of rh110267_smo at contour 
levels computed based on the image peak at 75.7, 41.6, 22.8, 12.5, 6.8, 3.8,
onto the Image Device.
... if pixel were specified instead of sky for Grid type then an identical
    plot with pixel labels will be displayed.

Overlaying contours on an existing plot with different colors:

First run tvimcontour once to figure out which contour levels should go 
with which color.  Once that's done:
cl> tvimcontour rh110267_smo sky pixel "75.0,45.0,25.0" gcolor="w"
cl> imcontour rh110267_smo sky pixel "7.0,4.0" graph_device=imdB perim- labout-
cl> gflush

For detailed explanation and other examples reference the IMCONTOUR 
Help File.




When inputing a value less than 1, such as .5, an input of "0.5" is accepted while ".5" is not. This is an IRAF bug.

One can precess from 1950 to 2000 (coordinates in 1950, image in 2000) but the reverse does not work properly (image in 1950 [i.e. an Einstein image], coordinates in 2000).


See the documentation on ERRCREATE(help ERRCREATE ) for a description of the error arrays and also the help explain_errors for a more complete discussion of errors in PROS.

See the documentation on imcontour (help imcontour ) for a description of the Imcontour Task.

See the documentation on gridpars (help gridpars ) for a description of the available WCS grid labeling parameters.

See the documentation on skypix (help skypix ) for a description of a coordinate system conversion task.

See the documentation on Imsmooth (help imsmooth ) for a description of the Imsmooth task.

See the documentation on Imcompress (help imcompress ) for a description of the Imcompress task.

See the documentation on Qpoe filtering (help qpoe ) for a description of the spatial filter user interface.

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