Coyote Graphics Programs

These are programs from the Coyote Library that are specifically identified as being associated with the Coyote Graphics System. Documentation for Coyote Graphics routines is now available on-line.

Alphabetical List of Commands

cgARROW Draws an arrow in a graphics window.
cgAXIS A device/color independent wrapper for the AXIS command.
cgBARPLOT Draws data as a bar plot.
cgBLENDIMAGE Allows the user to blend two images together.
cgBOXPLOT Draws data as a box and whisker plot.
cgCOLOR The heart and soul of the Coyote Graphics system!
cgCOLORBAR Creates direct graphics color bar.
cgCOLORFILL A device-independent and color-independent wrapper for the POLYFILL command.
cgCONLEVELS A function for creating contour levels for the cgContour command.
cgCONTAINER A modified IDL_Container object with properties important for Coyote Graphics.
cgCONTOUR A device-independent and color-independent wrapper for the CONTOUR command.
cgCONTROL A routine for setting and controlling cgWINDOW properties.
cgCOORD A coordinate object for Coyote Graphics routines.
cgDCBAR A discrete color bar with a handful of colors and centered labels.
cgDEFAULTCOLOR This function defines a default color for Coyote Graphics routines.
cgDEFCHARSIZE A routine define the default character size for Coyote Graphics routines.
cgDELETE A routine to delete an cgWINDOW from the display.
cgDEMODATA Opens data files found in the IDL distribution.
cgDISPLAY A device-independent and color-independent wrapper for the WINDOW command.
cgERASE A wrapper for ERASE that erases window in white color.
cgHISTOPLOT Draws a histogram plot (direct graphics).
cgIMAGE Device independent replacement for TV. Works with !P.Multi and Position keyword.
cgIMAGEINFO Works with cgIMAGE to display interactive image locations and values.
cgLOADCT A drop-in replacement for LOADCT with additional functionality.
cgPLOT A device-independent and color-independent wrapper for the PLOT command.
cgPLOTS A device-independent and color-independent wrapper for the PLOTS command.
cgPOLYGON A device-independent and color-independent program for creating filled or unfilled polygons.
cgPS2PDF A device-independent way to create PDF files from PostScript intermediary files.
cgPS2RASTER Create BMP, GIF, JPEG, PNG, and TIFF files from PostScript intermediary files.
cgQUERY A utility routine to gather information about cgWINDOW applications on the display.
cgRANDOMINDICES Create random indices without replacement (unique indices).
cgSCATTER2D Creates a scatter plot between two variables.
cgSET A WSet command for cgWINDOW.
cgSHOW A WShow command for cgWINDOW.
cgSNAPSHOT Device independent replacement/upgrade for TVRD. Creates raster files directly.
cgSURF A device-independent and color-independent wrapper to the SURFACE and SHADE_SURF commands.
cgSURFACE A full-rotating, object graphics surface command with texture mapping.
cgSYMBOL Draws device independent Greek (φ, ξ, λ, etc.) and other symbols (Å, ≠, ≡, etc.) in programs.
cgTEXT A wrapper for XYOUTS that writes (and places) text in a color independent manner.
cgWINDOW_GETDEFS Gets default values for cgWINDOW.
cgWINDOW_SETDEFS Sets default values for cgWINDOW.
cgWINDOW A "smart" graphics window. Resizeable with automatic file output.

	cgARROW
	This program draws an arrow on a graphics display. It is similar to the old Arrow command in IDL that now conflicts with the Arrow object in IDL 8. Set the WINDOW keyword to add this command to an cgWindow application.

	cgAXIS
	This program is a wrapper for the AXIS command and is meant to work seamlessly with the other other Coyote Graphics programs in this device independent, color independent series. Set the WINDOW keyword to add this command to an cgWindow application.

	cgBARPLOT
	Draws data as a bar plot.

cgBLENDIMAGE

This is an extremely simple program that will "blend" or "fuse" two 24-bit true-color images using alpha blending. You set the alpha value to a number between 0 and 1 to select the percentage of background image pixels to use in the blended image. For example, ALPHA=0.8 will use 80% of the background pixel values and 20% of the foreground pixel values in the blended image. The program is a wrapper to the cgImage command and can use all the features and keywords of that command. The figure below shows two MODIS images on the left (MOD02) and middle (MOD29), and the blended image on the right. An ALPHA value of 0.75 was used to create the blended image.

A blended image.

	cgBOXPLOT
	Draws data as box and whisker plots. Here is example output from plotting the Michaelson-Morely data from their speed of light experiments.

cgCOLOR

This program is a completely device-independent program for specifying colors by name. You can ask for and load any one (or all) of the nearly 200 colors defined in the program by name. The colors available are the ones defined for the PickColorName program:

The cgColor program colors.

To see a list of all the colors available by name, type this:

   IDL> Print, cgColor(/Names), Format='(5(A14, 2x))'
         WHITE            SNOW           IVORY     LIGHTYELLOW        CORNSILK
         BEIGE        SEASHELL           LINEN    ANTIQUEWHITE          PAPAYA
        ALMOND          BISQUE        MOCCASIN           WHEAT       BURLYWOOD
           TAN       LIGHTGRAY        LAVENDER      MEDIUMGRAY            GRAY
     SLATEGRAY        DARKGRAY        CHARCOAL           BLACK        HONEYDEW
     LIGHTCYAN      POWDERBLUE         SKYBLUE  CORNFLOWERBLUE       CADETBLUE
     STEELBLUE      DODGERBLUE       ROYALBLUE            BLUE            NAVY
     PALEGREEN      AQUAMARINE     SPRINGGREEN            CYAN       TURQUOISE
 LIGHTSEAGREEN        SEAGREEN     FORESTGREEN            TEAL     GREENYELLOW
    CHARTREUSE       LAWNGREEN           GREEN       LIMEGREEN       OLIVEDRAB
         OLIVE       DARKGREEN   PALEGOLDENROD           KHAKI       DARKKHAKI
        YELLOW            GOLD       GOLDENROD   DARKGOLDENROD     SADDLEBROWN
          ROSE            PINK       ROSYBROWN      SANDYBROWN            PERU
     INDIANRED       CHOCOLATE          SIENNA      DARKSALMON          SALMON
   LIGHTSALMON          ORANGE           CORAL      LIGHTCORAL       FIREBRICK
       DARKRED           BROWN         HOTPINK        DEEPPINK         MAGENTA
        TOMATO       ORANGERED             RED         CRIMSON       VIOLETRED
        MAROON         THISTLE            PLUM          VIOLET          ORCHID
  MEDIUMORCHID      DARKORCHID      BLUEVIOLET          PURPLE       SLATEBLUE
 DARKSLATEBLUE             WT1             WT2             WT3             WT4
           WT5             WT6             WT7             WT8            TAN1
          TAN2            TAN3            TAN4            TAN5            TAN6
          TAN7            TAN8            BLK1            BLK2            BLK3
          BLK4            BLK5            BLK6            BLK7            BLK8
          GRN1            GRN2            GRN3            GRN4            GRN5
          GRN6            GRN7            GRN8            BLU1            BLU2
          BLU3            BLU4            BLU5            BLU6            BLU7
          BLU8            ORG1            ORG2            ORG3            ORG4
          ORG5            ORG6            ORG7            ORG8            RED1
          RED2            RED3            RED4            RED5            RED6
          RED7            RED8            PUR1            PUR2            PUR3
          PUR4            PUR5            PUR6            PUR7            PUR8
          PBG1            PBG2            PBG3            PBG4            PBG5
          PBG6            PBG7            PBG8            YGB1            YGB2
          YGB3            YGB4            YGB5            YGB6            YGB7
          YGB8            RYB1            RYB2            RYB3            RYB4
          RYB5            RYB6            RYB7            RYB8             TG1
           TG2             TG3             TG4             TG5             TG6
           TG7             TG8        OPPOSITE

The normal calling sequence for producing device-independent drawing colors, will look similar to this. The first parameter is the name of the color you want, the second parameter is the color table index where you would like to load the specified color.

   axisColor = cgCOLOR("Green", !D.Table_Size-2)
   backColor = cgCOLOR("Dark Gray", !D.Table_Size-3)
   dataColor = cgCOLOR("Yellow", !D.Table_Size-4)
   Plot, Findgen(11), Color=axisColor, Background=backColor, /NoData
   OPlot, Findgen(11), Color=dataColor

If color decomposition is turned off, then the color is loaded at the specified index. If color decomposition is turned on, then no color is loaded into the color table.

If a color index is not specified and color decomposition is turned off, then the specified color is loaded into the !P.Color index.

The output of these commands looks like this:

An example of using the cgCOLOR program to specify colors.

The value that is returned by cgCOLOR depends upon the keywords used to call it and on the version of IDL you are using. In general, the return value will be either a color index number where the specified color is loaded by the program, or a 24-bit color value that can be decomposed into the specified color on true-color systems.

If you are running IDL 5.2 or higher, the program will determine which return value to use, based on the color decomposition state at the time the program is called. If you are running a version of IDL before IDL 5.2, then the program will return the color index number. This behavior can be overruled in all versions of IDL by setting the DECOMPOSED keyword. If this keyword is 0, the program always returns a color index number. If the keyword is 1, the program always returns a 24-bit color value.

If the TRIPLE keyword is set, the program always returns the color triple, no matter what the current decomposition state or the value of the DECOMPOSED keyword. This is useful, for example, if you want to load a color in the color table yourself.

   IDL> TVLCT, cgColor('dodger blue', /Triple), 10

If the ALLCOLORS keyword is used, then instead of a single value, modified as described above, then all the color values are returned in an array. In other words, the return value will be either an NCOLORS-element vector of color table index numbers, an NCOLORS-element vector of 24-bit color values, or an NCOLORS-by-3 array of color triples.

This program can also read an ASCII file of color names and values, so you don't have to use the nearly 200 colors provided.

And if you prefer to have the user select a color name, you can use the SELECTCOLOR keyword. (This requires PickColorName.) For example, suppose you want the RGB color triple of a user-supplied color. You would type this:

   IDL> color = cgCOLOR(/SelectColor, /Triple)
   IDL> Print, color

The output keyword COLORSTRUCTURE is useful if you want to get all of the colors in a structure variable with the color names as fields in the structure.

   IDL> d = cgCOLOR(/AllColors, ColorStructure=c)
   IDL> Plot, Findgen(11), Color=c.green, Background=c.charcoal, /NoData
   IDL> OPlot, Findgen(11), Color=c.dodgerblue

It is also possible to specify a vector of color names. For example, if you are overploting several lines in a plot, and you wish to each to have a different color, you might do this:

   x = Findgen(101) * 10/101.
   y = FltArr(3,101)
   FOR j=0,2 DO y[j,*] = cgDemoData(17)
   cgPlot, x, y[0,*], AxisColor='yellow', Background='charcoal', /NoData
   colors = ['dodger blue', 'indian red', 'pale green']
   FOR j=0,2 DO cgPlot, x, y[j,*], Color=colors[j], /Overplot

The plot might look something like this.

An example of using the cgCOLOR program to specify colors.

cgCOLORBAR

This program shows you one way to create a color bar for your programs. This color bar appears exactly the same in a PostScript file as it does on your display. You can easily create continuous or discrete color bars.

Color bars created with the cgColorbar program.

	cgCOLORFILL
	This program is a wrapper for the POLYFILL command. It fills a polygon with a color or "texture." Set the WINDOW keyword to add this command to an cgWindow application.

cgCONLEVELS

The cgContour program specializes in producing equally spaced contour intervals. But, depending on the data, the levels are not always "nicely" spaced or formatted. The role of the cgConLevels function is to address this problem by providing an easy and intuitive way to produce contour levels that look nice on contour plots.

Here is code that produces a "normal" contour plot with 10 equally-spaced contour intervals.

    cgDisplay, WID=0
    data = Scale_Vector(cgDemoData(2), 0.1, 4534.5)
    cgLoadCT, 33, NColors=10, Bottom=1
    cgContour, data, NLevels=10, /Fill, /Outline, $
       Position=[0.1, 0.1, 0.9, 0.75], C_Colors=Indgen(10)+1
    cgColorbar, NColors=9, Bottom=1, /Discrete, /Fit, $
       Range=[Min(data), Max(data)], OOB_High=10, OOB_Low='white'

A normal contour plot with 10 equally spaced contour intervals.

Here is code that use cgConLevels to produce the contour levels.

    cgDisplay, WID=1
    data = Scale_Vector(cgDemoData(2), 0.1, 4534.5)
    cgLoadCT, 33, NColors=10, Bottom=1
    levels = cgConLevels(data, Factor=100, MINVALUE=0)
    cgContour, data, Levels=levels, /Fill, /Outline, $
       Position=[0.1, 0.1, 0.9, 0.75], C_Colors=Indgen(10)+1
    cgColorbar, NColors=9, Bottom=1, /Discrete, /Fit, $
       Range=[Min(levels), Max(levels)], OOB_High=10, OOB_Low='white'

Using cgConLevels to produce equally spaced contour intervals.

A contour plot using cgConLevels to produce the contour intervals.

	cgCONTAINER
	This is a subclassed IDL_Container object that contains properties that are used with other Coyote Graphics routines.

cgCONTOUR

This program does for the CONTOUR command what the cgIMAGE command did for TV command. In other words, it makes the CONTOUR command obsolete, by giving users a useable device-independent, color-independent tool for producing graphics on modern computers. See the article Device Independent Contour Plots for additional information and screen shots. Below are pictures of basic Contour plots (on the left) verses cgContour plots (on the right), in both regular and filled versions. Set the Window keyword to add this command to an cgWindow application.

Regular contour plots.

Filled contour plots.

	cgCONTROL
	This routine allows the user to control various internal properties of a cgWindow application, including the ability to load images with and without immediate execution and the ability to programmatically create PostScript and raster file output from the window. The program is essentially a conduit to the SetProperty method of the underlying cgWindow object.

	cgCOORD
	This is a subclassed cgContainer object that maintains a rectangular data coordinate system for other Coyote Graphics objects and programs.

cgDCBAR

This program produces a discrete color bar with a handful, say 3 to 20 colors. Labels are centered (either horizontally or vertically) for each color, and the labels can be rotated, if needed, to keep an uncluttered display. The colorbar can be displayed either horizontally or vertically anywhere in the display window. You can learn more about how this program works by reading the Discrete Color Bar article on my web page.

A discrete color bar..

cgDEFAULTCOLOR

The purpose of this function is to choose a default color for Coyote Graphics routines. The input can be a string, a byte or integer, or a long integer. If the input is a long integer, the function will evaluate the value depending upon the current color state. If using indexed color, and the long integer is in the range 0-255, the long integer is interpreted as a color table index number. The output is generally passed to cgColor to obtain the actual color used in the program.

    color = cgDefaultColor(inputColor, Default='Opposite')
    IF Size(color, /TNAME) EQ 'STRING' THEN color = cgColor(color)

cgDEFCHARSIZE

This program selects the default character size for Coyote Graphics programs. Character size is based on several factors, including operating system, font type, and whether multiple plots are being displayed. In no case is the character size changed by the program if the !P.Charsize system variable is not set to its default value of 0.0. The character sizes returned are meant to emulate the slightly larger default character sizes used in the IDL 8 function graphics system.

	cgDELETE
	This command allows you to delete any or all cgWindow applications on the display. cgWindow applications can be selected by window index number, window title, widget identifier, or object reference. Set the ALL keyword to delete all the cgWindow applications on the display.

cgDEMODATA

This program is a utility routine for reading data files that are found in the IDL distribution, primairly in the $IDL_DIR/examples/data subdirectory. I use it when I teach IDL courses to get data of various types so I don't have to keep opening and closing files all the time. It is not particularly well written, but many of my code examples work better when you have a tool for loading data quickly. :-)

cgDISPLAY

This program is a wrapper for the WINDOW command. It erases a graphics window in a device and color independent way. Colors can be specified as color names. The default color is "white." This program automatically “protects ”the WINDOW command from devices that do not support windows. It is used to create IDL graphics windows in programs that are meant to work identically on the display and in other devices, such as the PostScript device, that do not support windows. If issued while in the PostScript device, a "window" with the same aspect ratio as the window that would be created on the display is specified. Using this program to open windows is one way to ensure your PostScript output looks identical to your display output.

	cgERASE
	This program is a wrapper for the ERASE command. It erases a graphics window in a device and color independent way. Colors can be specified as color names. The default color is "white." Set the WINDOW keyword to erase (delete) all the commands from an cgWindow graphics display before the display is erased with the specified color.

cgHISTOPLOT

A program for drawing a histogram plot that actually looks like a histogram plot. The histogram bars can be filled with lines (for black and white printing) or with colors. By setting an OPLOT keyword, you can overplot histograms on already exisiting axes. The cumulative probability distribution function can be obtained and/or plotted on the histogram plot. Set the WINDOW keyword to add this command to an cgWindow application.

The cgHISTOPLOT program.

cgIMAGE

This program allows you to display and position an image in a output display window with the Position keyword, just like other IDL graphics output. The advantage of this is that output looks the same in PostScript windows as well as display windows and it is trivial to use images along with other IDL graphics commands in the same window. The aspect ratio of the image can be preserved in the output window if desired. The program has been updated to honor the !P.Multi setting, so you can position images in windows exactly the way you do plots. This is a replacement program for the TV command. The program automatically determines if an 8-bit or 24-bit image is being displayed and sets the Decomposition and True keywords appropriately. This is a true device-, image-, and display-independent program. This is far and away the most useful program in my library!

The program has been updated on 18 March 2008 to accept a SCALE keyword that will allow the image argument to be byte scaled before display. An AXES keyword has also been added, which will add a set of axes to the image.

	cgIMAGEINFO
	This program works with cgIMAGE to allow the user to interactively determine image location and values for the displayed image. Further information is contained in this article on my web page.

cgLOADCT

A utility routine that is a drop-in replacement for LOADCT, with additional functionality and a correction to one of my favorite pet peeves. A REVERSE keyword allows the user to reverse the color table vectors prior to loading. A CLIP keyword allows the user to clip the normal color table vector to just a portion of the original color table vectors. I find this useful, for example, when I want a reduced number of colors in the color table, and I want to exclude the color table end-colors (for most IDL color tables these are black and white).

For example, suppose I wish to use the Standard Gamma color table (color table 5), but I wish to exclude, the black color at the bottom, and the white color at the top. I might type: "cgLOADCT, 5, CLIP=[16,240]". The color bar at top in the figure below was created by loading colors with this command:

   IDL> LoadCT, 5, NCOLORS=8

The color bar below was created by loading colors with this command:

   IDL> cgLoadCT, 5, NCOLORS=8, CLIP=[16,240]

Colorbars with colors loaded with LOADCT and cgLOADCT

In addition, one of my favorite pet peeves is corrected by having all color table loading done silently. Updated on 14 May 2008 to support Brewer Colors. You will need to download the fsc_brewer.tbl file from Coyote Library to use this functionality. Install it either in the $IDL_DIR/resource/colors directory or in any directory in the IDL path.

	cgPLOT
	This program does for the PLOT command what the cgIMAGE command did for TV command. In other words, it makes the PLOT command obsolete, by giving users a useable device-independent, color-independent tool for producing graphics on modern computers. Set the WINDOW keyword to add this command to an cgWindow application.

cgPLOTS

This program is a device-independent, color-independent wrapper for the PLOTS command. Data colors (Color keyword), symbol colors (SymColor keyword), and symbol size (SymSize keyword) can all be vectors, unlike the PLOTS command. This allows you to draw plots with multicolored lines, multicolored symbols, and/or multisized symbols. Set the WINDOW keyword to add this command to an cgWindow application.

   IDL> data = cgDemoData(1)
   IDL> time = Scale_Vector(Findgen(101), 0, 6)
   IDL> LoadCT, 33, /Silent
   IDL> cgPlot, time, data, /NODATA, XTITLE='Time', YTITLE='Signal'
   IDL> cgPlotS, time, data, PSYM=-16, COLOR=BytScl(data), $
           SYMCOLOR=BytScl(data), SYMSIZE=Scale_Vector(data, 1.0, 2.5)

cgPlots functionality

	cgPOLYGON
	This command allows you draw a filled or unfilled polygon on the display. Polygons can be created in two or three dimensions, and the fill color can be different from the polygon outline color.

cgPS2PDF

This program takes advantage of third-party free software (Ghostscript, pstopdf, epstopdf, etc.) to create a machine independent way to create PDF files from PostScript intermediate files. It is not my intention to reinvent the wheel, but I did need a way to create PDF files automatically from within a cgWindow program, and this program does the job. On-line documentation for this program is available .

	cgPS2RASTER
	This program takes advantage of the ImageMagick convert command to convert PostScript intermediate files to BMP, GIF, JPEG, PNG, or TIFF raster files in a machine independent way. On-line documentation for this program is available .

cgQUERY

This command allows you obtain information about all the cgWindow applications currently on the display. You can obtain their window index numbers, the identifiers of their top-level base widgets, their window titles, and their object references. If the CURRENT keyword is set, the same information can be obtained for just the current cgWindow application.

   IDL> windowIDs = cgQuery(WIDGETID=tlbIDs, OBJECTREF=objRefs, TITLE=winTitles, COUNT=count)
   IDL> FOR j=0,count-1 DO Print, windowIDs[j], '  ', winTitles[j]

cgRANDOMINDICES

This command allows the user to select a certain number of random indices out of a selection vector. The indices are selected without replacement, which means you get a list of unique indices. (None are repeated.) For example, to select 10 random indices out of a vector of 100 random indices, you would type this.

   IDL> indices = cgRandomIndices(100, 10, SEED=seed)
   IDL> Print, indices
        7  13  20  21  32  44  50  66  80  93

	cgSCATTER2D
	This program allows you to create a scatter plot between two variables. It is similar to a plot command, but in addition it optionally calculates the Pearson correlation coefficient and plots a best-fit straight line though the data. The fitting parameters can be retrieved from the program and/or displayed on the data plot. On-line documentation for the program is available.

	cgSNAPSHOT
	This program is a device independent replacement for the IDL TVRD program. It returns an 8-bit image when called on 8-bit displays and a 24-bit pixel interleaved image when called on 24-bit displays. Optional keywords can produce BMP, GIF, JPEG, PICT, PNG, and TIFF file output automatically.

	cgSURF
	This program does for the SURFACE and SHADE_SURF commands what the cgIMAGE command did for TV command. In other words, it makes the SURFACE and SHADE_SURF commands obsolete, by giving users a useable device-independent, color-independent tool for producing graphics on modern computers. Set the WINDOW keyword to add this command to an cgWindow application.

cgSURFACE

This program has been completely re-written in Nov 2010 to be a fully-capable surface command along the lines of the traditional surface command, cgSurf. It uses most of the the same keywords and acts in a similar fashion, but adds a great deal more functionality, including interactivity. Users can rotate and zoom into and out of the surface with the mouse, change colors and other surface properties at will, and save the surface to a number of output file types, including PostScript. Four lights illuminate the surface, and users have complete control over the color and intensity of these lights. The lights can be turned on or off to change surface features. Any 2D or true-color image can be added to the surface as a texture map.

This program won the IDL Code Contest, sponsored by Research Systems, Inc. to inaugurate their User Contribution Library in November 2002.


cgSurface is a non-traditional traditional graphics command for interacting with surfaces.

cgTEXT

This program is a wrapper for XYOUTS and is meant to work seamlessly with the other cg*** programs in this device independent, color independent series. It can choose its color based on the background color of the graphics window. If the PLACE keyword is set, the user can click inside the current graphics window to set text at the cursor location. Set the WINDOW keyword to add this command to an cgWindow application.

   IDL> cgText, 0.5, 0.5, 'Centered Text', /ALIGNMENT=0.5, COLOR='dodger blue'
   IDL> cgText, /PLACE, 'Use CURSOR to Locate this Text', COLOR='red8'

	cgSET
	This command is the equivalent of the WSet command for normal IDL graphics windows. It allows you to select a cgWindow application on the display and make it the "current" cgWindow application. Graphics commands are normally added to the current graphics display window. cgWindow applications can be selected by window index number, window title, widget identifier, or object reference.

	cgSHOW
	This command is the equivalent of the WShow command for normal IDL graphics windows. It allows you to move a cgWindow application forwand on the display without making it the "current" cgWindow application. Graphics commands are normally added to the current graphics display window. cgWindow applications can be selected by window index number, window title, widget identifier, or object reference.

	cgSYMBOL
	This command allows you to create device independent Greek (φ, ξ, λ, etc.) and other symbols (Å, ≠, ≡, etc.) in your IDL programs. The symbols produced will work correctly on the display and in a PostScript file. See the article Using Greek Symbols for additional information.

	cgWINDOW_GETDEFS
	This routine allows the user to get global default values for configuring cgWindow.

	cgWINDOW_SETDEFS
	This routine allows the user to set global default values for configuring cgWindow.

cgWINDOW

This command is a resizeable graphics window for displaying IDL graphics commands. In addition to resizing the graphics window, this command can create BMP, GIF, JPEG, PNG, TIFF raster files, as well as true PostScript output. This command is invoked automatically by setting the Window keyword on Coyote Graphics routines. If ImageMagick is available on your machine, you will have the additional option of making raster image files of the window contents directly from PostScript files. This completely eliminates any concern for poor quality fonts in raster file output.

The cgWindow program can accept multiple graphics commands. Commands can be added, deleted, replaced, and listed. Multiple cgWindow programs can be opened at once, and you have easy access to the commands in any graphics window. Here is an example of how to display a filled contour plot with a color bar.

   IDL> cgLoadCT, 4, /Brewer, /Reverse, NColors=12, Bottom=1
   IDL> cgWindow, 'cgContour', cgDemoData(2), NLevels=12, /Fill, C_Colors=Indgen(12)+1, $
           Position=[0.1,0.1,0.9,0.75]
   IDL> cgWindow, 'cgContour', cgDemoData(2), Color='Charcoal', NLevels=12, /Overplot, /AddCmd
   IDL> cgWindow, 'cgColorbar', Divisions=12, Range=[Min(data), Max(data)], NColors=12, $
            Bottom=1, XMinor=0, XTicklen=1.0, /AddCmd

cgWindow allows multiple commands that can be moved and edited.

If used with Coyote Graphics routines (by setting the WINDOW keyword), cgWindow can be used in exactly the same way normal IDL graphics windows are used. That is to say, resizeable, smart graphics windows are available for all IDL users.

Version of IDL used to prepare this article: IDL 7.0.1.

Last Updated: 22 December 2011