colorbar.pro

这是IDL语言中用于做Color bar的小程序

;+
; NAME:
;   COLORBAR
;
; PURPOSE:
;
;       The purpose of this routine is to add a color bar to the current
;       graphics window.
;
; AUTHOR:
;
;   FANNING SOFTWARE CONSULTING
;   David Fanning, Ph.D.
;   1645 Sheely Drive
;   Fort Collins, CO 80526 USA
;   Phone: [phone]
;   E-mail: [e-mail]
;   Coyote's Guide to IDL Programming: http://www.dfanning.com/
;
; CATEGORY:
;
;       Graphics, Widgets.
;
; CALLING SEQUENCE:
;
;       COLORBAR
;
; INPUTS:
;
;       None.
;
; KEYWORD PARAMETERS:
;
;       ANNOTATECOLOR: The name of the "annotation color" to use. The names are those for
;                     FSC_COLOR, and using the keyword implies that FSC_COLOR is also in
;                     your !PATH. If this keyword is used, the annotation color is loaded
;                     *after* the color bar is displayed. The color will be represented
;                     as theColor = FSC_COLOR(ANNOTATECOLOR, COLOR). This keyword is provide
;                     to maintain backward compatibility, but also to solve the problem of
;                     and extra line in the color bar when this kind of syntax is used in
;                     conjunction with the indexed (DEVICE, DECOMPOSED=0) model is used:
;
;                          LoadCT, 33
;                          TVImage, image
;                          Colorbar, Color=FSC_Color('firebrick')
;
;                     The proper syntax for device-independent color is like this:
;
;                          LoadCT, 33
;                          TVImage, image
;                          Colorbar, AnnotateColor='firebrick', Color=255
;
;       BOTTOM:       The lowest color index of the colors to be loaded in
;                     the bar.
;
;       CHARSIZE:     The character size of the color bar annotations. Default is 1.0.
;
;       COLOR:        The color index of the bar outline and characters. Default
;                     is !P.Color..
;
;       DIVISIONS:    The number of divisions to divide the bar into. There will
;                     be (divisions + 1) annotations. The default is 6.
;
;       FONT:         Sets the font of the annotation. Hershey: -1, Hardware:0, True-Type: 1.
;
;       FORMAT:       The format of the bar annotations. Default is '(I0)'.
;
;       INVERTCOLORS: Setting this keyword inverts the colors in the color bar.
;
;       MAXRANGE:     The maximum data value for the bar annotation. Default is
;                     NCOLORS.
;
;       MINRANGE:     The minimum data value for the bar annotation. Default is 0.
;
;       MINOR:        The number of minor tick divisions. Default is 2.
;
;       NCOLORS:      This is the number of colors in the color bar.
;
;       POSITION:     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.
;
;       RANGE:        A two-element vector of the form [min, max]. Provides an
;                     alternative way of setting the MINRANGE and MAXRANGE keywords.
;
;       REVERSE:      Setting this keyword reverses the colors in the colorbar.
;
;       RIGHT:        This puts the labels on the right-hand side of a vertical
;                     color bar. It applies only to vertical color bars.
;
;       TICKNAMES:    A string array of names or values for the tick marks.
;
;       TITLE:        This is title for the color bar. The default is to have
;                     no title.
;
;       TOP:          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:     Setting this keyword give a vertical color bar. The default
;                     is a horizontal color bar.
;
; COMMON BLOCKS:
;
;       None.
;
; SIDE EFFECTS:
;
;       Color bar is drawn in the current graphics window.
;
; RESTRICTIONS:
;
;       The number of colors available on the graphics display device (not the
;       PostScript device) is used unless the NCOLORS keyword is used.
;
;       Requires the FSC_COLOR program from the Coyote Library:
;
;          http://www.dfanning.com/programs/fsc_color.pro
;
; EXAMPLE:
;
;       To display a horizontal color bar above a contour plot, type:
;
;       LOADCT, 5, NCOLORS=100
;       CONTOUR, DIST(31,41), POSITION=[0.15, 0.15, 0.95, 0.75], $
;          C_COLORS=INDGEN(25)*4, NLEVELS=25
;       COLORBAR, NCOLORS=100, POSITION=[0.15, 0.85, 0.95, 0.90]
;
; MODIFICATION HISTORY:
;
;       Written by: David W. Fanning, 10 JUNE 96.
;       10/27/96: Added the ability to send output to PostScript. DWF
;       11/4/96: Substantially rewritten to go to screen or PostScript
;           file without having to know much about the PostScript device
;           or even what the current graphics device is. DWF
;       1/27/97: Added the RIGHT and TOP keywords. Also modified the
;            way the TITLE keyword works. DWF
;       7/15/97: Fixed a problem some machines have with plots that have
;            no valid data range in them. DWF
;       12/5/98: Fixed a problem in how the colorbar image is created that
;            seemed to tickle a bug in some versions of IDL. DWF.
;       1/12/99: Fixed a problem caused by RSI fixing a bug in IDL 5.2. Sigh... DWF.
;       3/30/99: Modified a few of the defaults. DWF.
;       3/30/99: Used NORMAL rather than DEVICE coords for positioning bar. DWF.
;       3/30/99: Added the RANGE keyword. DWF.
;       3/30/99: Added FONT keyword. DWF
;       5/6/99: Many modifications to defaults. DWF.
;       5/6/99: Removed PSCOLOR keyword. DWF.
;       5/6/99: Improved error handling on position coordinates. DWF.
;       5/6/99. Added MINOR keyword. DWF.
;       5/6/99: Set Device, Decomposed=0 if necessary. DWF.
;       2/9/99: Fixed a problem caused by setting BOTTOM keyword, but not NCOLORS. DWF.
;       8/17/99. Fixed a problem with ambiguous MIN and MINOR keywords. DWF
;       8/25/99. I think I *finally* got the BOTTOM/NCOLORS thing sorted out. :-( DWF.
;       10/10/99. Modified the program so that current plot and map coordinates are
;            saved and restored after the colorbar is drawn. DWF.
;       3/18/00. Moved a block of code to prevent a problem with color decomposition. DWF.
;       4/28/00. Made !P.Font default value for FONT keyword. DWF.
;       9/26/00. Made the code more general for scalable pixel devices. DWF.
;       1/16/01. Added INVERTCOLORS keyword. DWF.
;       5/11/04. Added TICKNAME keyword. DWF.
;       9/29/05. Added REVERSE keywords, which does the *exact* same thing as
;           INVERTCOLORS, but I can never remember the latter keyword name. DWF.
;       1/2/07. Added ANNOTATECOLOR keyword. DWF.
;       4/14/07. Changed the default FORMAT to I0. DWF.
;       5/1/07. Unexpected consequence of default format change is colorbar annotations
;           no longer match contour plot levels. Changed to explicit formating of
;           colorbar axis labels before PLOT command. DWF.
;       5/25/07. Previous change has unanticipated effect on color bars using
;           logarithmic scaling, which is not really supported, but I have an
;           article on my web page describing how to do it: http://www.dfanning.com/graphics_tips/logcb.html.
;           Thus, I've fixed the program to accommodate log scaling, while still not OFFICIALLY
;           supporting it. DWF.
;-
;
;###########################################################################
;
; LICENSE
;
; This software is OSI Certified Open Source Software.
; OSI Certified is a certification mark of the Open Source Initiative.
;
; Copyright