top cgColorbar

Graphics

cgColorbar [, /ADDCMD] [, ANNOTATECOLOR=string] [, BOTTOM=integer] [, CHARPERCENT=float] [, CHARSIZE=float] [, CLAMP=float] [, COLOR=string] [, /DISCRETE] [, DIVISIONS=integer] [, /FIT] [, FONT=integer] [, FORMAT=string] [, /INVERTCOLORS] [, MAXRANGE=MAXRANGE] [, MINOR=integer] [, MINRANGE=float] [, NCOLORS=integer] [, NEUTRALINDEX=integer] [, NODISPLAY=NODISPLAY] [, OOB_FACTOR=float] [, OOB_HIGH=string] [, OOB_LOW=string] [, PALETTE=byte] [, POSITION=float] [, RANGE=float] [, /REVERSE] [, /RIGHT] [, TICKLEN=float] [, TICKNAMES=string] [, TITLE=string] [, /TOP] [, /VERTICAL] [, /XLOG] [, XTITLE=string] [, /YLOG] [, YTITLE=string] [, /WINDOW] [, _REF_EXTRA=_REF_EXTRA]

Keywords

ADDCMD in optional type=boolean default=0

Set this keyword to add the command to the resizeable graphics window cgWindow.

ANNOTATECOLOR in optional type=string default=opposite

The name of the "annotation color" to use. The names are those for cgCOLOR. If this keyword is used, the annotation color is loaded after the color bar is displayed. This keyword is provided to maintain backward compatibility, but also to solve the potential problem of an extra line showing up in the color bar when the COLOR keyword is used in indexed color mode. In other words, use ANNOTATECOLOR in place of COLOR for complete color model independent results.

BOTTOM in optional type=integer default=0

The lowest color index of the colors to be loaded in the color bar.

CHARPERCENT in optional type=float default=0.85

A value from 0.0 go 1.0 that is multiplied by the CHARSIZE to produce the character size for the color bar. This value is only used if CHARSIZE is undefined. This keyword is primarily useful for using color bars in resizeable graphics windows (cgWindow).

CHARSIZE in optional type=float

The character size of the color bar annotations. Default is cgDefCharsize()*charPercent.

CLAMP in optional type=float

A two-element array in data units. The color bar is clamped to these two values. This is mostly of interest if you are "window-leveling" an image. The clamp is set to the "window" of the color bar. Normally, when you are doing this, you would like the colors outside the "window" to be set to a neutral color. Use the NEUTRALINDEX keyword to set the netural color index in the color bar. (See the Examples section for more information.)

COLOR in optional type=string

The name of the color to use for color bar annotations. Ignored unless passed the name of a cgColor color. The default value is to use the ANNOTATECOLOR.

DISCRETE in optional type=boolean default=0

Set this keyword to configure certain properties of the color bar to make discrete color blocks for the color bar. This works best if you are using a handful of colors in the color bar (e.g, 8-16).

DIVISIONS in optional type=integer

The number of divisions to divide the bar into. There will be (divisions + 1) annotations. The default is 0 if using the default color bar formatting, which allows the plot command to determine how many divisions to make. Otherwise, if you are specifying some other format for the tick labels, the default number of divisions is six.

FIT in optional type=boolean default=0

If this keyword is set, the colorbar "fits" itself to the normalized coordinates of the last graphics command executed. In other words, for a horizontal color bar, postition[[0,2]] = !X.Window, and for a vertical color bar, position[[1,3]] = !Y.Window. Other positions are adjusted to put the colorbar "reasonably" close to the plot. The fit many not always be accurate. If you are fitting to an image, be sure to set the SAVE keyword on cgImage to establish a data coordinate system.

FONT in optional type=integer default=!P.Font

Sets the font of the annotation. Hershey: -1, Hardware:0, True-Type: 1.

FORMAT in optional type=string

The format of the color bar annotations. Default is "", which allows the Plot command to determine the appropriate format.

INVERTCOLORS in optional type=boolean default=0

Setting this keyword inverts the colors in the color bar.

MAXRANGE in optional

The maximum data value for the color bar annotation. Default is NCOLORS.

MINOR in optional type=integer default=2

The number of minor tick divisions.

MINRANGE in optional type=float default=0.0

The minimum data value for the bar annotation.

NCOLORS in optional type=integer default=256

This is the number of colors in the color bar.

NEUTRALINDEX in optional type=integer

This is the color index to use for color bar values outside the clamping range when clamping the color bar with the CLAMP keyword. If this keyword is absent, the highest color table value is used for low range values and the lowest color table value is used for high range values, in order to provide contrast with the clamped region. (See the Examples section for more information.)

NODISPLAY in optional

This keyword is obsolete and is no longer used.

OOB_FACTOR in optional type=float default=1.0

The default is to make the length of the out-of-bounds triangle the same distance as the height (or width, in the case of a vertical color bar) of the color bar. If you would prefer a shorted triangle length, set this keyword to a value less than zero (e.g., 0.5). If you prefer a longer length, set this keyword to a value greater than zero. The "standard" length will be multiplied by this value.

OOB_HIGH in optional type=string

The name of an out-of-bounds high color. This color will be represented by a triangle on the right or top of the color bar. If the color is a string byte value (e.g., "215"), then this color in the current color table is used. The color can also be a three-element color triple (e.g., [240, 200, 65]).

OOB_LOW in optional type=string

The name of an out-of-bounds low color. This color will be represented by a triangle on the left or bottom of the color bar. If the color is a string byte value (e.g., "215"), then this color in the current color table is used. The color can also be a three-element color triple (e.g., [240, 200, 65]).

PALETTE in optional type=byte

A color palette containing the RGB color vectors to use for the color bar. The program will sample NCOLORS from the color palette.

POSITION in optional type=float

A four-element array of normalized coordinates in the same form as the POSITION keyword on a plot. Default is[0.88, 0.10, 0.95, 0.90] for a vertical bar and [0.10, 0.88, 0.90, 0.95] for a horizontal bar. See the FIT keyword, also.

RANGE in optional type=float

A two-element vector of the form [min, max]. Provides an alternative and faster way way of setting the MINRANGE and MAXRANGE keywords.

REVERSE in optional type=boolean default=0

An alternative keyword name (one I can actually remember!) for the INVERTCOLORS keyword. It reverses the colors in the color bar.

RIGHT in optional type=boolean default=0

This puts the labels on the right-hand side of a vertical color bar. It applies only to vertical color bars.

TICKLEN in optional type=float default=0.25

Set this keyword to the major tick length desired. Default is 0.25. Setting this keyword to a value greater than or equal to 0.5 will result in major tick marks extending the width of the color bar. Note that setting this keyword to 0.3 or greater will result in minor tick mark lengths being set to 0.01, which is almost too small to be seen. All direct graphics tick marks act in this (strange!) way.

TICKNAMES in optional type=string

A string array of names or values for the color bar tick marks.

TITLE in optional type=string

This is title for the color bar. The default is to have no title.

TOP in optional type=boolean default=0

This puts the labels on top of the bar rather than under it. The keyword only applies if a horizontal color bar is rendered.

VERTICAL in optional type=boolean default=0

Setting this keyword give a vertical color bar. The default is a horizontal color bar.

XLOG in optional type=boolean default=0

Set this keyword to use logarithmic scaling for the colorbar data range.

XTITLE in optional type=string

This keyword is ignored. Use the Title keyword to set a title for the color bar.

YLOG in optional type=boolean default=0

Set this keyword to use logarithmic scaling for the colorbar data range.

YTITLE in optional type=string

This keyword is ignored. Use the Title keyword to set a title for the color bar.

WINDOW in optional type=boolean default=0

Set this keyword to display the plot in a resizeable graphics window (cgWindow).

_REF_EXTRA in optional

Any keyword appropriate for the PLOT and AXIS commands is also accepted by keyword inheritance.

Examples

Author information

Author:

FANNING SOFTWARE CONSULTING: David W. Fanning 1645 Sheely Drive Fort Collins, CO 80526 USA Phone: 970-221-0438 E-mail: david@idlcoyote.com Coyote's Guide to IDL Programming: http://www.idlcoyote.com

Copyright:

Copyright (c) 2008-2012, Fanning Software Consulting, Inc.

History:

Change History: Written by: David W. Fanning, 4 February 2011, as a direct descendant of cgColorbar. Program developement stopped on cgColorbar as of this date, and this program has become a part of the Coyote Graphics System. Added FIT keyword. 28 Feb 2011. DWF Made default character size cgDefCharsize*0.85. 28 Feb 2011. DWF. Modified error handler to restore the entry decomposition state if there is an error. 17 March 2011. DWF Added CHARPERCENT keyword 18 March 2011. DWF. Added XTITLE and YTITLE keywords, which do nothing except prevent these keywords from being used inadvertently. 27 May 2011. DWF. Fixed a problem with assigning the color with the ANNOTATECOLOR keyword in the Z-graphics buffer. 30 Aug 2011. DWF. Changed the default DIVISIONS to 0 and the default FORMAT to "". 2 Sept 2011. DWF. Added code that will force MINRANGE and MAXRANGE values to be scalars. 5 Sept 2011. DWF. Problem with division by zero when FORMAT is not default value. Now, if format is the default value, then default is DIVISIONS=0, else DIVISIONS=6. Documented the TICKLEN keyword and set the default tick length to 0.25. 3 Oct 2011. DWF. Added the OOB_FACTOR, OOB_HIGH and OOB_LOW keywords. 5 Dec 2011. DWF. Added DISCRETE keyword. 7 Dec 2011. DWF. Changed the way the top axis was drawn, and had a problem with EXTRA keywords. Fixed. 20 Dec 2011. DWF. Modified to use cgDefaultColor for default color selection. 24 Dec 2011. DWF. Fixed a problem with color palettes by defining NCOLORS according to the number of colors in the palette. 19 March 2012. DWF. Set the maximum number of divisions at 59 to recognize the IDL plot limit for tick marks. 19 March 2012. DWF. Modifications to the FIT algorithm to make sure the color bar is completely inside the graphics window. Also fixed mis-spelled variable name. 20 March 2012. DWF.