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Basic Information on cgdisp


Task: cgdisp
Purpose: displays and overlays images on a PGPLOT device
Categories: plotting

        CGDISP displays/overlays images via contour plots, pixel map
        representations, vectors and scaled boxes on a PGPLOT device.
        Upto 3 contour plots, one pixel map, one vector plot and one box
        display may be overlaid in multi-panel plots of multi-channel
        images.  In addition overlay locations (plotted as crosses,
        boxes, circles, lines or see-through) may be specified from an
        ascii text file.
 
        Manipulation of the device colour lookup table is available
        when you display with a pixel map representation (formerly
        called a "grey scale")
 

Key: in
        You may input up to seven images.  Up to three of these can
        be displayed via contour plots and one can be displayed via a
        colour pixel map representation.  One vector amplitude image and
        one vector position angle image (degrees; positive N -> E) can
        together be used to display a vector map (e.g. polarization
        vectors).  One image can be displayed as small scaled boxes (see
        below) and one image may be used as a mask.
 
        The "box" image is displayed by drawing little boxes (solid and
        hollow for positive and negative pixels) at the location of each
        selected pixel.  The size of the box scales with the value of
        the pixel.  This is a useful way to display rotation measure
        images for example. The mask image blanking mask is logically
        ANDed to all the other image masks before they are displayed.
        The mask image is not displayed.
 
        If more than one image is specified, they must have identical
        first and second dimensions.  However, you can overlay
        combinations of 2-D with 3-D images (e.g. multi-channel images
        with a continuum image) provided all the 3-D images have the
        same third dimension.  These images can be input in any order
        (see TYPE).  Wild card expansion is supported.  No default.

Key: type
        Specifies the type of each image, respectively, listed in the IN
        keyword. Minimum match is supported (note that "pixel" was
        formerly "grey" [which is still supported]).   Choose from:
 
         "contour"   (contour;            up to 3 of these)
         "pixel"     (pixel map;          up to 1 of these)
         "amplitude" (vector amplitude;   up to 1 of these)
         "angle"     (vector pos'n angle; up to 1 of these)
         "box"       (box;                up to 1 of these)
         "mask"      (mask;               up to 1 of these)
 
        You can't give one of "amplitude" or "angle" without the other.
        Default is "pixel" for one image, "contour" if more than one.

Key: region
        Region of interest.  Choose only one spatial region (bounding
        box only supported), but as many spectral regions (i.e. multiple
        IMAGE specifications) as you like.   Each channel (or group of
        channels; see CHAN below) is drawn on a new sub-plot.
        NOTE: the region specification applies equally to all the
        input images.
        Default is full image

Key: xybin
        Upto 4 values.  These give the spatial increment and binning
        size in pixels for the x and y axes to be applied to the
        selected region.  If the binning size is not unity, it must
        equal the increment.  For example, to bin up the image by 4
        pixels in the x direction and to pick out every third pixel in
        the y direction, set XYBIN=4,4,3,1
        Defaults are 1,XYBIN(1),XYBIN(1),XYBIN(3)

Key: chan
        2 values. The first is the channel increment to step through the
        image in, the second is the number of channels to average, for
        each sub-plot.  Thus CHAN=5,3  would average groups of 3
        channels together, starting 5 channels apart such as: 1:3, 6:8,
        11:13 ...  The channels available are those designated by the
        REGION keyword.  A new group of channels (sub-plot) is started
        if there is a discontinuity in the REGION selected channels
        (such as IMAGE(10,20),IMAGE(22,30).  The combination of REGION
        and CHAN determines how many sub-plots there will be.
 
        In the case that you have input some combination of 2-D and 3-D
        images, CHAN refers to the 3-D image(s). Note that a channel
        is defined to be a pixel on the third axis of a cube, regardless
        of the cube's order (xyv or vxy say).
        Defaults are 1,1

Key: slev
        Up to 3 pairs of values, one for contour image. First value is
        the type of contour level scale factor.  "p" for percentage and
        "a" for absolute.   Second value is the factor to scale LEVS by.
        Thus, SLEV=p,1  would contour levels at LEVS * 1% of the image
        peak intensity.  Similarly, SLEV=a,1.4e-2 would contour levels
        at LEVS * 1.4E-2
        Default is no additional scaling of LEVS (i.e., "a",1.0)

Key: levs1
        The levels to contour for the first specified contour image are
        LEVS1 times SLEV (either percentage of the image peak or
        absolute).
        Defaults try to choose something vaguely useful.

Key: levs2
        Levels for the second contour image.

Key: levs3
        Levels for the third contour image.

Key: cols1
        PGPLOT colours for LEVS1 contours.  If one value is given it is
        used for all contours.  PGPLOT colour indices are
           0: background colour (black or white)
           1: foreground colour (white or black)
           2: red           3: green           4: blue
           5: cyan          6: magenta         7: yellow
           8: orange        9: lime           10: spring green
          11: azure        12: violet         13: rose
          14: dark grey    15: light grey

Key: cols2
        Colours for the second contour image.  Defaults to those for the
        first image.

Key: cols3
        Colours for the third contour image.  Defaults to those for the
        first image.

Key: range
        Up to N groups of four values, one group per sub-plot, where N
        is the maximum number of channels allowed by Miriad (currently
        32768).  The four values are
          - MINimum image intensity to display
          - MAXimum image intensity to display
          - Transfer function type:
              lin: linear
              sqr: square root
              log: logarithmic
              heq: histogram equalization
          - Colour lookup table:
                1: b&w
                2: rainbow
                3: linear pseudo colour
                4: floating zero colour contours
                5: fixed zero colour contours
                6: rgb
                7: background
                8: heat
                9: absolute b&w
               10-19: cubehelix (by D. Green, google cubehelix for info)
            Negate the table number to reverse the lookup table.
 
        The transfer function changes available with OPTIONS=FIDDLE
        are in addition to (on top of) the selections here, but the
        colour lookup table selections will replace those selected here.
 
        All subplots following the last one with a specified "range"
        will use the "range" settings from the previous subplot. In
        this way, one group of settings can be applied to all the
        subplots if desired.  The multiple subplot capability is useful
        if you have used IMCAT to put unlike images into planes of
        a cube and you wish to display them together.
 
        Default is linear between the image minimum and maximum with
        a b&w lookup table.   You can default the intensity range with
        zeros, viz. "range=0,0,log,-2" say.

Key: vecfac
        3 or 4 values.  A scale factor to multiply the vector image
        lengths (or box image widths) by, the x and y increments (in
        pixels) across the image at which to plot the vectors (or
        boxes), and optionally the length of the scale-bar vector
        (unset for no scale-bar). If you have set non unit values of
        XYBIN, the increments here refer to the binned pixels.  When
        VECFAC(1)=1, the vectors (boxes) are scaled so that the maximum
        amplitude (width) takes 1/20 of the (sub)plot size.
 
        The scale-bar gives a graphical representation of the vector
        lengths, which makes vector plots easier to interpret.  The
        scale-bar is drawn in the corner specified by the BEAMTYP key
        (defaulting to bottom-left if BEAMTYP is not specified). If
        VECFAC(4)=0, the scale bar is drawn the length of the longest
        vector; you can find out what this is using OPTIONS=FULL. For a
        fractional polarization vector map, setting VECFAC(4)=1
        corresponds to 100 per cent polarization. If VECFAC(1) >> 1,
        this will give a very long vector. For polarization intensity
        images, VECFAC(4) is specified in flux density.
 
        Defaults are 1.0, 2, VECFAC(2)
        Default is not to draw a scale-bar.

Key: boxfac
        3 values.  A scale factor to multiply the box image widths by,
        and the x and y increments (in pixels) across the image at which
        to plot the boxes).  If have set non unit values of XYBIN, the
        increments here refer to the binned pixels.  When BOXFAC(1)=1,
        the boxes are scaled so that there is a little bit of space
        between adjacent boxes.
        Defaults are 1.0, 2, BOXFAC(2)

Key: device
        The PGPLOT plot device, such as plot.plt/ps
        No default.

Key: nxy
        Number of sub-plots in the x and y directions on the page.
        Defaults choose something depending on your telescope.

Key: labtyp
        Up to 2 values.  The spatial label type of the x and y axes.
        Minimum match is active.  Select from:
 
         "hms"       the label is in H M S.S (e.g. for RA)
         "dms"       the label is in D M S.S (e.g. for DEC)
         "arcsec"    the label is in arcsecond offsets
         "arcmin"    the label is in arcminute offsets
         "arcmas"    the label is in milli-arcsec offsets
         "absdeg"    the label is in degrees
         "reldeg"    the label is in degree offsets
                     The above assume the pixel increment is in radians.
         "abspix"    the label is in pixels
         "relpix"    the label is in pixel offsets
         "abskms"    the label is in km/s
         "relkms"    the label is in km/s offsets
         "absghz"    the label is in GHz
         "relghz"    the label is in GHz offsets
         "absnat"    the label is in natural coordinates as defined by
                     the header.
         "relnat"    the label is in offset natural coordinates
         "none"      no label and no numbers or ticks on the axis
 
        All offsets are from the reference pixel.
        Defaults are "relpix", LABTYP(1)   except if LABTYP(1)="hms"
        when LABTYP(2) defaults to "dms" (to give RA and DEC)

Key: beamtyp
      Up to 6 values. Set if you want a small polygon to be drawn to
      represent the beam FWHM. Setting beamtyp to "b,l" is sufficient to
      draw a solid beam; "b,l,4" will result in a cross-hatched
      beam.  Use 'n' if you don't want a beam at all.
      The six parameters are:
 
      - Beam vertical positioning: can be "t" (top), or "b" (bottom). No
        default.
      - Beam horizontal positioning: can be "l" (left), or "r"
        (right). Default "l"
 
      The next four parameters apply only to the first image specified
      with the in keyword.  If there are multiple, different beams to
      draw (for example, if different uv data were used to produce
      images with different beam shapes), all subsequent beams are drawn
      as open polygons.
 
      - Hatching style:
         1    solid (default)
         2    outline
         3    hatched
         4    cross-hatched
      - Hatching angle (default 45 degrees).
      - Hatching line separation (default 1).
      - Line-width for outlines, hatching and cross-hatching (default 1)

Key: options
        Task enrichment options. Minimum match of all keywords is
        active.
 
        "abut" means don't leave any white space between subplots.  The
          default is to leave a little bit between subplots, and
          OPTIONS=GAPS leaves a lot of space and labels eacg subplot
          separately.
        "beamAB", where "A" is one of "b" or "t" and
                        "B" is one of "l" or "r"
          means draw the beam FWHM on the plot in the corner indicated
          by the "AB" location. This option is deprecated: use the
          keyword "beamtyp" instead.
        "blacklab" means that, if the device is white-background, draw
          the axis labels in black. Default is red.
        "conlabel" means label the contour values on the actual
          contours.  The PGPLOT routine that does this is not very
          bright.  You will probably get too many labels.  If you bin
          the image up with keyword XYBIN, say, by a factor of 2, you
          will get about 1/2 as many labels.  If desperate use the
          overlay facility (keyword OLAY) to manually label contours.
        "fiddle" means enter a routine to allow you to interactively
          change the display lookup table.  You can cycle through a
          variety of colour lookup tables, as well as alter a linear
          transfer function by the cursor location, or by selecting
          predefined transfer functions (linear, square root,
          logarithmic, histogram equalization)
 
          For hard copy devices (e.g. postscript), a keyboard driven
          fiddle is offered; you can cycle through different colour
          tables and invoke the predefined transfer functions, but the
          linear fiddler is not available.   Note that if you are using
          "cgdisp" from a script, so that interactive fiddling is not
          appropriate, you can use the "range" keyword to specify the
          transfer function and colour lookup tables.
        "full" means do full plot annotation with contour levels, pixel
          displa range, file names, reference values, etc.  Otherwise
          more room for the plot is available.
        "gaps" means leave large gaps between subplots and individually
          label the axes of each subplot. By default, the subplots will
          have a small amount of white space between each subplot and
          they will only be labelled around the borders of the full
          page.  See also OPTIONS=ABUT to eliminate the small amount of
          white space.
        "grid" means draw a coordinate grid on the plot rather than just
          ticks
        "mirror" causes all specified contour levels for all images
          to be multiplied by -1 and added to the list of contours
        "nodistort" means that angularly-defined overlays do not distort
          with the coordinate grid.  If you are displaying a large area
          of the sky, such that the non-linearities in the coordinate
          system can be seen, then by default, the overlays (keyword
          OLAY) will distort with the coordinate grid if you are using
          angular units for the overlay locations and half sizes.  Thus
          star overlays will rotate and stretch, circles will distort
          similarly.  Overlays given in non-angular units will always be
          undistorted.
        "noepoch" means don't write the epoch value into the axis labels
        "noerase" means don't erase a rectangle into which the "3-axis"
          values and the overlay ID strings are written.
        "nofirst" means don't write the first x-axis label on any
          subplots except for the left-most one. This may avoid label
          overwrite.
        "corner" means only write labels in the lower left corner of any
          subplot
        "relax" means issue warnings when image axis descriptors are
          inconsistent (e.g. different pixel increments) instead
          of a fatal error.  Use at your peril.
        "rot90" rotates vectors by an extra 90 degrees.  Useful
          to convert E-vectors into B-vectors
        "signs"  Normally, when plotting vectors, CGDISP assumes that
          North is up and East to the left.  If OPTIONS=SIGNS, then
          it assumes that E and N are in the direction of increasing
          X and Y.
        "single" means that when you have selected OPTIONS=FIDDLE and
          you have more than one subplot per page, activate the fiddle
          option after each subplot rather than the default, which is
          to fiddle only at the end.  In the latter case, the histogram
          equalization, if invoked, will have been computed with the
          image in the last subplot only.
        "solneg1" means make negative contours solid and positive
          contours dashed for the first contour image. The default,
          and usual convention is the reverse.
        "solneg2" SOLNEG1 for the second contour image.
        "solneg3" SOLNEG1 for the third contour image.
        "trlab" means label the top and right axes as well as the bottom
          and left ones.  This can be useful when non-linear coordinate
          variation across the field makes the ticks misaligned
        "unequal" means draw plots with unequal scales in x and y
          so that the plot surface is maximally filled.  The default
          is for equal scales in x and y.
        "wedge" means that if you are drawing a pixel map, also draw
          and label a wedge to the right of the plot, showing the map
          of intensity to colour.
        "3pixel" means label each sub-plot with the pixel value of
          the third axis.
        "3value" means label each sub-plot with the appropriate
          value of the third axis (e.g. velocity or frequency for an
          xyv ordered cube, position for a vxy ordered cube).
          Both "3pixel" and "3value" can appear, and both will be
          written on the plot.  They are the average values when
          the third axis is binned up with CHAN.  If the third axis
          is not velocity or frequency, the units type for "3VALUE"
          will be chosen to be the complement of any like axis in the
          first 2. E.g. the cube is in vxy order and
          LABTYP=ABSKMS,ARCSEC the units for the "3VALUE" label will be
          arcsec.  If LABTYP=ABSKMS,HMS the "3VALUE" label will be DMS
          (if the third [y] axis is declination).  See also keyword
          "3format" where you can input the format for the "3value"
          labelling.

Key: 3format
        If you ask for "3value" labelling, this keyword allows you
        specify the FORTRAN format of the labelling.  I have given
        up trying to invent a decent algorithm to choose this. Examples
        are "1pe12.6", or "f5.2" etc   If you leave this blank cgdisp
        will try something that you probably won't like.

Key: lines
        Up to 6 values.  The line widths for the axes, each contour
        image (in the order of TYPE), the vector image, and any
        overlays.  If there are less than 3 contour images or no vector
        image, the vector image/overlay line widths shift left.
        Line widths must be integers.
        Defaults are 1,1,1,1,1,1

Key: break
        Up to 3 values. The intensity levels for the break between
        solid and dashed contours for each contour image.
        Defaults are 0.0,0.0,0.0

Key: csize
        Up to 4 values.  Character sizes in units of the PGPLOT default
        (which is ~ 1/40 of the view surface height) for the plot axis
        labels, the velocity/channel label, the overlay ID string
        (if option "write" in OLAY used) label, and the contour
        value labels (see options=conlab).
        Defaults try to choose something sensible.  Use 0.0 to default
        any particular value. E.g., 1.4, 0, 0, 0.5

Key: scale
        Up to 2 values.  Scales in natural axis units/mm with which to
        plot in the x and y directions.  For example, if the increments
        per pixel are in radians, then this number would be radians/mm
        (note that for RA axes you give radians on the sky per mm).
        Although this choice of unit may be cumbersome, it makes no
        assumptions about the axis type, so is more flexible.   If you
        also chose OPTIONS=EQUAL then one of your scales, if you set
        both and differently, would be over-ruled.  If you give only
        one value, the second defaults to that.
        Defaults choose scales to fill the page optimally. To default
        the first but the second, use 0.0,scale(2)

Key: comment1
        A comment line to add at the bottom of the plot, use quotes
        if the comment includes spaces. The comments will not appear
        when options=full is specified.

Key: comment2
        A comment line to add at the bottom of the plot, use quotes
        if the comment includes spaces.

Key: comment3
        A comment line to add at the bottom of the plot, use quotes
        if the comment includes spaces.

Key: comment4
        A comment line to add at the bottom of the plot, use quotes
        if the comment includes spaces.

Key: comment5
        A comment line to add at the bottom of the plot, use quotes
        if the comment includes spaces.

Key: olay
        The name of a file containing a list of overlay descriptions.
        Wild card expansion is active and the default is no overlays.
 
        Miriad task CGCURS OPTIONS=CURSOR,LOG,CGDISP  can be used to
        make an overlay file.
 
        Entries in the overlay file can be white space or comma
        delimitered or both.  All lines beginning with # are ignored.
 
                        **** DO NOT USE TABS ****
 
        Double quotes " are used below to indicate a string.  The "
        should not be put in the file.   For all the string parameters
        discussed below, you can abbreviate them with minimum match.
 
 
        Each line describes an overlay and should be as follows:
 
         ##### The first 5 parameters in each line must be
 
          1      2       3     4    5
         --------------------------------
         OFIG  XOTYPE  YOTYPE  ID  WRITE
 
       where
 
        OFIG is the type of overlay; choose from
         "sym"     pgplot symbol number (give centre, symbol, and size)
         "star"    star (i.e. cross; give centre and half-sizes)
         "box"     box (give centre and half-sizes)
         line    line segment (give ends)
         "vector"  directed line segment (give centre, length, and
                   position angle)
         "circle"  filled in circle (give centre and radius)
         "ocircle" open circle (give centre and radius)
         "ellipse" filled-in ellipse (give centre, half axes and p.a.)
         "oellipse open ellipse (give centre, half axes and p.a.)
         "clear"   nothing, so you can write the overlay ID string (see
                   below) without the overlay
 
        You can specify a directive on a line of its own, it applies to all
        overlays that follow, or until overwritten by another directive:
         "colour n"  Change colour of marker, specify pgplot colour index
         "lwid w"    Change linewidth, specify a value from 1-201
         offset    See below for details.
 
        XOTYPE and YOTYPE  give the units of the overlay location (and
        overlay half-sizes) contained in the file for the x- and y-
        directions, respectively.  Choose from:
         "hms", "dms", "arcsec", "arcmin", "absdeg", "reldeg", "abspix",
         "relpix", "absnat", "relnat", "absghz", "relghz",
         "abskms", & "relkms"  as described in the keyword LABTYP.
        Note that OTYPE does not depend upon what you specified for
        LABTYP.
 
        ID is an identifying overlay string which can be optionally
        written on the overlay; it MUST be in the overlay file whether
        you write it on the plot or not).  The ID string is written in
        the corner for "star" and "box", at the end for line, and in
        the centre for "circle" and "clear".  The underscore character
        "_" is treated a special case and is replaced by a blank before
        plotting.  In this way, you can write several words as the
        overlay ID; you connect them with underscores in the overlay
        file, and cgdisp strips them out before plotting.
 
        WRITE is "yes" or "no" to specify if the overlay ID is to be
        written in the overlay figure or not.
 
 
         ##### Parameters beyond number 5 depend upon OFIG, XOTYPE, and
         YOTYPE
 
         6   7    8   9  10  11  12  13  14  15          OFIG
         --------------------------------------   -----------------
         X   Y   SY  SS  CS  CE                   sym
         X   Y   XS  YS  CS  CE                   star, box
         X1  Y1  X2  Y2  CS  CE                   line
         X   Y   VL  PA  SS  A1  A1  A3  CS  CE   vector
         X   Y   R   CS  CE                       circle,  ocircle
         X   Y   R1  R2  PA  CS  CE               ellipse, oellipse
         X   Y   CS  CE                           clear
 
        X,Y defines the center of the overlay in the nominated OTYPE
        coordinate system (X- and Y-OTYPE can be different).
        (X1,Y1) & (X2,Y2) are the end points of the line segment in the
        nominated OTYPE (mixed OTYPEs are supported here too).
        For %OTYPE = "abspix ", "relpix", "arcsec", "arcmin", "absdeg",
                     "reldeg", "absghz", "relghz", "abskms", "relkms",
                     "absnat" & "relnat" X,Y,X1,Y1,X2,Y2 are single
                     numbers.
 
        For %OTYPE = "hms" or "dms", the X and/or Y location is/are
        replaced by three numbers such as HH MM SS.S or DD MM SS.S.
        Thus, if XOTYPE = hms and YOTYPE = dms then the file for
        OFIG=box, say, should have lines like
 
          HH MM SS.S   DD MM SS.S   XS   YS  CHAN
 
        XS, YS are the overlay half-sizes in the following units:
        %OTYPE = "abspix" and "relpix" in pixels
                 "hms"    and "dms"    in arcseconds
                 "arcsec"              in arcseconds
                 "arcmin"              in arcminutes
                 "absdeg" and "reldeg" in degrees
                 "absghz" and "relghz" in GHz
                 "abskms" and "relkms" in km/s
                 "absnat" and "relnat" in natural coordinates
        XS, YS are optional for OFIG="box" and "star".  The defaults
        are XS = 2, YS = XS pixels.
 
        CS to CE is the channel range (image planes) on which to put the
        overlays.  If you specify only CS than the overlay is put on
        that channel.  If CS = 0 the overlays are put on all channels.
        In all cases, CS and CE are optional and the default is 0 (all
        channels)
 
        SY is the pgplot symbol to use for "sym".
 
        SS is the pgplot character height to use for "sym" and "vector".
        May be set to zero for vectors to omit the arrowhead.  Default
        is the character height used for overlay string.
 
        VL is the length of the vector in pixels.
 
        PA is the position angle in degrees, positive N -> E.
 
        A1, A2, and A3 are the PGPLOT arrowhead style parameters:
        A1 is the fill-style, 1 (default) for filled or anything else
           for outline.
        A2 is the acute angle of the arrow point, in degrees.  Default
           45.0.
        A3 is the fraction of the triangular arrowhead that is cut away
           from the back.  Default 0.3.
 
        R is the radius of circle overlays in the units given in the
        above list according to XOTYPE only.
 
        R1 and R2 are the ellipse major and minor axes half-widths,
        both in units according to XOTYPE.
 
 
        ##### OFIG = COLOUR (or COLOR)
 
        A COLOUR directive can be included at any point in the overlay
        file in the format
 
          COLOUR   INDEX
 
        where the literal "COLOUR" or "COLOR" (without the quotes)
        starts in column 1, followed by the PGPLOT colour index.  This
        changes the graphics overlay colour until the next COLOUR
        directive is processed.  PGPLOT colour indices are listed above
        for the cols1 parameter.  The default colour index is 9.
 
        ##### OFIG = LWID
 
        An LWID directive can be included at any point in the overlay
        file in the format
 
          LWID   WIDTH
 
        where the literal "LWID" (without the quotes) starts in column
        1, followed by the PGPLOT line width in units of 0.005 inch
        (about 0.13 mm) and must be an integer in the range 1-201.  This
        changes the graphics line width until the next LWID directive is
        processed.  The default width is 1.
 
        ##### OFIG = OFFSET
 
        An OFFSET directive can be included at any point in the overlay
        file in the format
 
          OFFSET   XOFF   YOFF
 
        where the literal "OFFSET" (without the quotes) starts in
        column 1, followed by X and Y offsets which are applied to all
        succeeding overlay file locations.
 
               X = X + XOFF;   Y = Y + YOFF
 
        These offsets must be in the same units as the %OTYPE of
        succeeding directives.  It is intended so that your overlay
        locations can be in, say, arcsec relative to some location which
        is not the reference pixel of the image (which is what CGDISP
        ultimately wants).   You then specify, with the OFFSET
        directive, the offsets between the reference pixel of the
        contour/pixel map images and the actual reference location of
        your overlay locations.
 
        You can have as many OFFSET directive as you like in the file.
        All succeeding directives will apply these offsets until new
        ones are defined.  If the directive does not appear, naturally
        no additional offsets are added.
 
        The OFFSET directive is not applied to ANY position fields in
        succeeding directives that have %OTYPEs that are "hms" or "dms".
        I am too lazy to code it.
 
        Example olay file with colour changes:
        # default colour is green
        ocircle hms dms green_circle no 09 02 34.81 -46 14 00.05 150.0 0 0
        color 2
        ocircle hms dms red_circle no 09 02 14.0 -46 24 36.0 828.0 0 0
        color 4
        ocircle hms dms blue_circle no 09 01 01.593  -46 38 55.498  439.09 0 0
 
Revision: 1.27, 2015/07/09 23:25:48 UTC

Generated by miriad@atnf.csiro.au on 21 Jun 2016