Manipulation of the device colour lookup table is available when you display with a pixel map representation (formerly called a "grey scale")
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.
"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.
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
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
- 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 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.
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.
"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)
- 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)
"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.
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
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
"colour" See below. "lwid" See below. "offset" See below.
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 coordinatesXS, 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
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
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.
disp.for,v 1.11 2011/06/06 22:15:26 pteuben Exp $