File: cgdemodata.pro

package info (click to toggle)
coyote 2019.01.29-1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster
  • size: 6,316 kB
  • sloc: python: 184; makefile: 14; sh: 13
file content (829 lines) | stat: -rw-r--r-- 28,598 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
; docformat = 'rst'
;
; NAME:
;   cgDemoData
;
; PURPOSE:
;   The purpose of this function is to read a selection of standard
;   data sets that are found in the normal IDL distribution in the
;   subdirectory $IDL_DIR/examples/data. At least 25 data sets are
;   available in all categories of data. The user selects one of the
;   possible data sets with the mouse. Several of the data sets 
;   simply create data used to illustrate graphics commands (numbers 1-3), 
;   and two of the data sets produce random data. Data set 17 produces 
;   a random vector of 101 elements. Data set 18 produces a 2D array of 
;   random values, suitable for display as a contour plot or image.
;
;******************************************************************************************;
;                                                                                          ;
;  Copyright (c) 2011, by Fanning Software Consulting, Inc. All rights reserved.           ;
;                                                                                          ;
;  Redistribution and use in source and binary forms, with or without                      ;
;  modification, are permitted provided that the following conditions are met:             ;
;                                                                                          ;
;      * Redistributions of source code must retain the above copyright                    ;
;        notice, this list of conditions and the following disclaimer.                     ;
;      * Redistributions in binary form must reproduce the above copyright                 ;
;        notice, this list of conditions and the following disclaimer in the               ;
;        documentation and/or other materials provided with the distribution.              ;
;      * Neither the name of Fanning Software Consulting, Inc. nor the names of its        ;
;        contributors may be used to endorse or promote products derived from this         ;
;        software without specific prior written permission.                               ;
;                                                                                          ;
;  THIS SOFTWARE IS PROVIDED BY FANNING SOFTWARE CONSULTING, INC. ''AS IS'' AND ANY        ;
;  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES    ;
;  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT     ;
;  SHALL FANNING SOFTWARE CONSULTING, INC. BE LIABLE FOR ANY DIRECT, INDIRECT,             ;
;  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED    ;
;  TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;         ;
;  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND             ;
;  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT              ;
;  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS           ;
;  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.                            ;
;******************************************************************************************;
;
;+
;   The purpose of this function is to read a selection of standard
;   data sets that are found in the normal IDL distribution in the
;   subdirectory $IDL_DIR/examples/data. At least 25 data sets are
;   available in all categories of data. The user selects one of the
;   possible data sets with the mouse. Several of the data sets 
;   simply create data used to illustrate graphics commands (numbers 1-3), 
;   and two of the data sets produce random data. Data set 17 produces 
;   a random vector of 101 elements. Data set 18 produces a 2D array of 
;   random values, suitable for display as a contour plot or image.
;
; :Categories:
;    Utilities
;    
; :Examples:
;       To load the world elevation data set::
;
;           image = cgDemoData(7)
;       
; :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
;
; :History:
;     Change History::
;       Written by:  David W. Fanning, 5 March 1999.
;       Added some additonal random data capability. 29 April 99. DWF
;       Added IMAGES keyword. 31 March 2000. DWF.
;       Fixed a problem with the CANCEL button. 25 Oct 2002. DWF.
;       Added new JPEG, DICOM, TIFF, and PGN images. 30 Oct 2002. DWF.
;       Modified old program units to work with IDL strict arrays. 29 June 2003. DWF
;       Yikes! Somehow lost the event handler for the CANCEL button! Fixed. 1 Jan 2012. DWF.
;       Added 2D Combined Gaussian data set. Renamed utility routines. 22 Jan 2013. DWF.
;
; :Copyright:
;     Copyright (c) 2011-2013, Fanning Software Consulting, Inc.
;-
;
; NAME:
;       SMOOTH2
; PURPOSE:
;       Do multiple smoothing. Gives near Gaussian smoothing.
; CATEGORY:
; CALLING SEQUENCE:
;       b = smooth2(a, w)
; INPUTS:
;       a = array to smooth (1,2, or 3-d).  in
;       w = smoothing window size.          in
; KEYWORD PARAMETERS:
; OUTPUTS:
;       b = smoothed array.                 out
; COMMON BLOCKS:
; NOTES:
; MODIFICATION HISTORY:
;       R. Sterner.  8 Jan, 1987.
;       Johns Hopkins University Applied Physics Laboratory.
;       RES  14 Jan, 1987 --- made both 2-d and 1-d.
;       RES 30 Aug, 1989 --- converted to SUN.
;       R. Sterner, 1994 Feb 22 --- cleaned up some.
;
; Copyright (C) 1987, Johns Hopkins University/Applied Physics Laboratory
; This software may be used, copied, or redistributed as long as it is not
; sold and this copyright notice is reproduced on each copy made.  This
; routine is provided as is without any express or implied warranties
; whatsoever.  Other limitations apply as described in the file disclaimer.txt.
;
;-------------------------------------------------------------
;+
; Does multiple smoothing. A routine from the JHUAPL IDL Library.
; 
; :Params:
;    i: in, required
;        The input array to be smoothed.
;    w: in, required, type=integer
;        The size of the smoothing window. Forced to be an odd integer. 
; :Keywords:
;    help: in, optional, type=boolean, default=0
;        Set this keyword to print function syntax help.
;-
    function cgdemodata_smooth2, i, w, help=hlp

    if (n_params(0) lt 2) or keyword_set(hlp)  then begin
      print,' Do multiple smoothing. Gives near Gaussian smoothing.'
      print,' b = cgdemodata_smooth2(a, w)'
      print,'   a = array to smooth (1,2, or 3-d).  in'
      print,'   w = smoothing window size.          in'
      print,'   b = smoothed array.                 out'
      return, -1
    endif

    w1 = w > 2
    w2 = w/2 > 2

    i2 = smooth(i, w1)
    i2 = smooth(i2, w1)
    i2 = smooth(i2, w2)
    i2 = smooth(i2, w2)

    return, i2
    end


;-------------------------------------------------------------
;
; NAME:
;       MAKEZ
; PURPOSE:
;       Make simulated 2-d data.  Useful for software development.
; CATEGORY:
; CALLING SEQUENCE:
;       data = makez( nx, ny, w)
; INPUTS:
;       nx, ny = size of 2-d array to make.                   in
;       w = smoothing window size (def = 5% of sqrt(nx*ny)).  in
; KEYWORD PARAMETERS:
;       Keywords:
;         /PERIODIC   forces data to match at ends.  Will not work
;           for smoothing windows much more than about 30% of n.
;         SEED=s      Set random seed for repeatable results.
;         LASTSEED=s  returns last random seed used.
; OUTPUTS:
;       data = resulting data array (def = undef).            out
; COMMON BLOCKS:
;       makez_com
; NOTES:
; MODIFICATION HISTORY:
;       R. Sterner,  29 Nov, 1986.
;       R. Sterner,  1994 Feb 22 --- Rewrote from new makey.
;
; Copyright (C) 1986, Johns Hopkins University/Applied Physics Laboratory
; This software may be used, copied, or redistributed as long as it is not
; sold and this copyright notice is reproduced on each copy made.  This
; routine is provided as is without any express or implied warranties
; whatsoever.  Other limitations apply as described in the file disclaimer.txt.
;
;-------------------------------------------------------------
;+
; Make simulated 2-d data. A routine from the JHUAPL IDL Library.
; 
; :Params:
;    nx: in, required
;        The X size of the data to be created.
;    ny: in, required, type=integer
;        The Y size of the data to be created.
;    w: in, required, type=integer
;        The smoothing window size.
; :Keywords:
;    help: in, optional, type=boolean, default=0
;        Set this keyword to print function syntax help.
;    lastseed: out, optional
;        Returns the last random seed used.
;    periodic: in, optional, type=boolean, default=0
;        Set this keyword to force the data to match at either end.
;    seed: in, optional
;        Sets the random seed for repeatable results.
;-
    function cgdemodata_makez, nx, ny, w, help=hlp, lastseed=lseed, periodic=per, seed=seed0
      

        common cgdemodata_makez_com, seed
    ;-----------------------------------------------------------------
    ;   Must store seed in common otherwise it is undefined
    ;   on entry each time and gets set by the clock but only
    ;   to a one second resolution (same random data for a whole sec).
    ;-----------------------------------------------------------------

    if keyword_set(hlp) then begin
      print,' Make simulated 2-d data.  Useful for software development.'
      print,' data = cgdemodata_makez( nx, ny, w)'
      print,'   nx, ny = size of 2-d array to make.                   in'
      print,'   w = smoothing window size (def = 5% of sqrt(nx*ny)).  in'
      print,'   data = resulting data array (def = undef).            out'
      print,' Keywords:'
      print,'   /PERIODIC   forces data to match at ends.  Will not work'
      print,'     for smoothing windows much more than about 30% of n.'
      print,'   SEED=s      Set random seed for repeatable results.'
      print,'   LASTSEED=s  returns last random seed used.'
      return, -1
    endif

    ;-----  Return last random seed or set new  -----
    if n_elements(seed) ne 0 then lseed=seed else lseed=-1
    if n_elements(nx) eq 0 then return,0            ; That was all.
        if n_elements(seed0) ne 0 then seed = seed0

    ;-----  Default smoothing window size  ---------
    if n_elements(w) eq 0 then w = .05*sqrt(long(nx)*ny) > 5

    ;-----  Compute size of edge effect  --------
    lo = fix(w)/2 + fix(w)  ; First index after edge effects.
    ntx = nx + 2*lo     ; X size extended to include edge effects.
    nty = ny + 2*lo     ; Y size extended to include edge effects.
    hix = ntx - 1 - lo  ; Last X index before edge effects.
    hiy = nty - 1 - lo  ; Last Y index before edge effects.

    ;-----  Make data  ---------------------------
    r = randomu(seed, ntx, nty) ; Random starting data.
    seed0 = seed            ; Return new seed.
    if keyword_set(per) then begin  ; Want periodic data.
      r[ntx-2*lo,0] = r[0:2*lo-1,*] ; Copy part of random data.
      r[0,nty-2*lo] = r[*,0:2*lo-1]
    endif
    s = cgdemodata_smooth2(r,w)        ; Smooth.
    s = s[lo:hix, lo:hiy]       ; Trim edge effects.
    s = s - min(s)          ; Normalize.
    s = s/max(s)

    lseed = seed            ; Return last seed.

    return, s
    end
;-------------------------------------------------------------
;
; NAME:
;       MAKEY
; PURPOSE:
;       Make simulated data.  Useful for software development.
; CATEGORY:
; CALLING SEQUENCE:
;       data = makey( n, w)
; INPUTS:
;       n = number of data values to make.                in
;       w = smoothing window size (def = 5% of n).        in
; KEYWORD PARAMETERS:
;       Keywords:
;         /PERIODIC   forces data to match at ends.  Will not work
;           for smoothing windows much more than about 30% of n.
;         SEED=s      Set random seed for repeatable results.
;         LASTSEED=s  returns last random seed used.
; OUTPUTS:
;       data = resulting data array (def = undef).        out
; COMMON BLOCKS:
;       makey_com
; NOTES:
; MODIFICATION HISTORY:
;       R. Sterner,  2 Apr, 1986.
;       Johns Hopkins University Applied Physics Laboratory.
;       RES 21 Nov, 1988 --- added SEED.
;       R. Sterner, 2 Feb, 1990 --- added periodic.
;       R. Sterner, 29 Jan, 1991 --- renamed from makedata.pro.
;       R. Sterner, 24 Sep, 1992 --- Added /NORMALIZE.
;       R. Sterner, 1994 Feb 22 --- Greatly simplified.  Always normalize.
;
; Copyright (C) 1986, Johns Hopkins University/Applied Physics Laboratory
; This software may be used, copied, or redistributed as long as it is not
; sold and this copyright notice is reproduced on each copy made.  This
; routine is provided as is without any express or implied warranties
; whatsoever.  Other limitations apply as described in the file disclaimer.txt.
;
;-------------------------------------------------------------
;+
; Make simulated data vector. A routine from the JHUAPL IDL Library.
; 
; :Params:
;    n: in, required
;        The size of the data vector to be created.
;    w: in, required, type=integer
;        The smoothing window size.
; :Keywords:
;    help: in, optional, type=boolean, default=0
;        Set this keyword to print function syntax help.
;    lastseed: out, optional
;        Returns the last random seed used.
;    periodic: in, optional, type=boolean, default=0
;        Set this keyword to force the data to match at either end.
;    seed: in, optional
;        Sets the random seed for repeatable results.
;-
    function cgdemodata_makey, n, w, seed=seed0, lastseed=lseed, $
      periodic=per, help=hlp

        common cgdemodata_makey_com, seed
    ;-----------------------------------------------------------------
    ;   Must store seed in common otherwise it is undefined
    ;   on entry each time and gets set by the clock but only
    ;   to a one second resolution (same random data for a whole sec).
    ;-----------------------------------------------------------------

    if keyword_set(hlp) then begin
      print,' Make simulated data.  Useful for software development.'
      print,' data = cgdemodata_makey( n, w)'
      print,'   n = number of data values to make.                in'
      print,'   w = smoothing window size (def = 5% of n).        in'
      print,'   data = resulting data array (def = undef).        out'
      print,' Keywords:'
      print,'   /PERIODIC   forces data to match at ends.  Will not work'
      print,'     for smoothing windows much more than about 30% of n.'
      print,'   SEED=s      Set random seed for repeatable results.'
      print,'   LASTSEED=s  returns last random seed used.'
      return, -1
    endif

    ;-----  Return last random seed or set new  -----
    if n_elements(seed) ne 0 then lseed=seed else lseed=-1
    if n_elements(n) eq 0 then return,0 ; That was all.
        if n_elements(seed0) ne 0 then seed = seed0

    ;-----  Default smoothing window size  ---------
    if n_elements(w) eq 0 then w = .05*n > 5

    ;-----  Compute size of edge effect  --------
    lo = long(w)/2L + long(w)   ; First index after edge effects.
    nt = n + 2*lo           ; Size extended to include edge effects.
    hi = nt - 1 - lo        ; Last index before edge effects.

    ;-----  Make data  ---------------------------
    r = randomu(seed, nt)       ; Random starting data.
    seed0 = seed            ; Return new seed.
    if keyword_set(per) then begin  ; Want periodic data.
      r[nt-2*lo] = r[0:2*lo-1]  ; Copy part of random data.
    endif
    s = cgdemodata_smooth2(r,w)        ; Smooth.
    s = s[lo:hi]            ; Trim edge effects.
    s = s - min(s)          ; Normalize.
    s = s/max(s)

    lseed = seed            ; Return last seed.

    return, s
    end

;
; NAME: 
;  gauss2d
; PURPOSE: 
;  Compute a two dimensional gaussian within an array.
; DESCRIPTION:
; CATEGORY:
;  Mathematical
; CALLING SEQUENCE:
;  pro gauss2d,nx,ny,x,y,fwhm,array
; INPUTS:
;  nx   - X size of output array
;  ny   - Y size of output array
;  x    - X location of gaussian in array
;  y    - Y location of gaussian in array
;  fwhm - Full width at half-maximum of gaussian.
; OPTIONAL INPUT PARAMETERS:
; KEYWORD INPUT PARAMETERS:
; OUTPUTS:
;  array - Result array with gaussian inserted.
; KEYWORD OUTPUT PARAMETERS:
; COMMON BLOCKS:
; SIDE EFFECTS:
; RESTRICTIONS:
; PROCEDURE:
; MODIFICATION HISTORY:
;  94/04/07, Written by Marc W. Buie, Lowell Observatory
;
;+
; Creates a two-dimensions Gaussian data set.
;
; :Params:
;     nx: in, required, type=integer
;        The X size of the output array.
;     ny: in, required, type=integer
;        The Y size of the output array.
;     x: in, required, type=integer
;        The X location of the Gaussian in the array.   
;     y: in, required, type=integer
;        The Y location of the Gaussian in the array.   
;     fwhm: in, required, type=float
;        The full width at half-maximum of Gaussian.
;     array: out, optional, type=float
;        The output array containing the Gaussian.
;-
pro cgdemodata_gauss2d,nx,ny,x,y,fwhm,array

   ehwd = fwhm/2.0/sqrt(alog(2.0))

   ix = findgen(nx)
   iy = findgen(ny)
   onex = replicate(1.0,nx)
   oney = replicate(1.0,ny)

   xarr = ((ix-x)/ehwd)^2 # oney
   yarr = onex # ((iy-y)/ehwd)^2

   rsq = xarr + yarr
   array = fltarr(nx,ny)

   ; Protection against underflow in exp call.
   big = where(rsq le 87.3, count)
   if count ne 0 then array[big] = exp(-rsq[big])

end


;+
; This event handler responds to the CANCEL button.
; 
; :Params:
;    event: in, required, type=structure
;        The event structure passed by the window manager from the CANCEL button.
;-
PRO cgDemoData_Cancel, event
    Widget_Control, event.top, /Destroy
END



;+
; Reads the data set from its current location.
; 
; :Params:
;    number: in, required, type=integer
;        The selection number.
;-
FUNCTION cgDemoData_ReadData, number

COMMON cgDemoData_SEED, seed

; Read a data set in the $IDL_DIR/examples/data subdirectory.

IF N_Elements(number) EQ 0 THEN BEGIN
   ok = Dialog_Message("Data set index number is required in cgDemoData.")
   RETURN, -1
ENDIF

CASE number OF

   0: BEGIN
      data = cgdemodata_makey(101, 5, Seed=1L) * 30.0
      END

   1: BEGIN
      data = cgdemodata_makez(41, 41, 8, Seed=-2L)  * 1550
      END

   2: BEGIN
      data = cgdemodata_makez(41, 41, 10, Seed=-5L)
      data = cgScaleVector(data, 0, 60)
      END

   3: BEGIN
      file = FILEPATH(SUBDIR=['examples', 'data'], 'galaxy.dat')
      data = BYTARR(256, 256)
      OPENR, lun, file, /GET_LUN
      READU, lun, data
      FREE_LUN, lun
      END

   4: BEGIN
      file = FILEPATH(SUBDIR=['examples', 'data'], 'ctscan.dat')
      data = BYTARR(256, 256)
      OPENR, lun, file, /GET_LUN
      READU, lun, data
      FREE_LUN, lun
      END

   5: BEGIN
      file = FILEPATH(SUBDIR=['examples', 'data'], 'abnorm.dat')
      data = BYTARR(64, 64, 15)
      OPENR, lun, file, /GET_LUN
      READU, lun, data
      FREE_LUN, lun
      END

   6: BEGIN
      file = FILEPATH(SUBDIR=['examples', 'data'], 'worldelv.dat')
      data = BYTARR(360,360)
      OPENR, lun, file, /GET_LUN
      READU, lun, data
      FREE_LUN, lun
      END

   7: BEGIN
      file = FILEPATH(SUBDIR=['examples', 'data'], 'head.dat')
      data = BYTARR(80, 100, 57)
      OPENR, lun, file, /GET_LUN
      READU, lun, data
      FREE_LUN, lun
      END

   8: BEGIN
      file = FILEPATH(SUBDIR=['examples', 'data'], 'cereb.dat')
      data = BYTARR(512, 512)
      OPENR, lun, file, /GET_LUN
      READU, lun, data
      FREE_LUN, lun
      END

   9: BEGIN
      file = FILEPATH(SUBDIR=['examples', 'data'], 'people.dat')
      data = BYTARR(192, 192, 2)
      OPENR, lun, file, /GET_LUN
      READU, lun, data
      FREE_LUN, lun
      END

  10: BEGIN
      file = FILEPATH(SUBDIR=['examples', 'data'], 'convec.dat')
      data = BYTARR(248, 248)
      OPENR, lun, file, /GET_LUN
      READU, lun, data
      FREE_LUN, lun
      END

  11: BEGIN
      file = FILEPATH(SUBDIR=['examples', 'data'], 'm51.dat')
      data = BYTARR(340, 440)
      OPENR, lun, file, /GET_LUN
      READU, lun, data
      FREE_LUN, lun
      END

  12: BEGIN
      file = FILEPATH(SUBDIR=['examples', 'data'], 'hurric.dat')
      data = BYTARR(440, 340)
      OPENR, lun, file, /GET_LUN
      READU, lun, data
      FREE_LUN, lun
      END

 13: BEGIN

        ; Create randomly-distributed (xyz) data.

      seed = -1L
      x = RANDOMU(seed, 41)
      y = RANDOMU(seed, 41)
      distribution = SHIFT(DIST(41,41), 25, 15)
      distribution = EXP(-(distribution/15)^2)

      lat = x * (24./1.0) + 24
      lon = y * 50.0/1.0 - 122
      temp = distribution(x*41, y*41) * 273
      data = FLTARR(3, 41)
      data(0,*) = lon
      data(1,*) = lat
      data(2,*) = temp
      END

 14: BEGIN

        ; Create randomly-distributed (xyz) data.

      seed = -1L
      x = RANDOMU(seed, 41)
      y = RANDOMU(seed, 41)
      distribution = SHIFT(DIST(41,41), 25, 15)
      distribution = EXP(-(distribution/15)^2)

      lat = x * (24./1.0) + 24
      lon = y * 50.0/1.0 - 122
      temp = distribution(x*41, y*41) * 273
      data = {lat:lat, lon:lon, temp:temp}
      END

 15: BEGIN

        ; The ROSE data set.

     file = FILEPATH(SUBDIR=['examples', 'data'], 'rose.jpg')
     Read_JPEG, file, data
     END

 16: BEGIN

        ; Random 1D vector of 101 elements.

     scale = RandomU(seed, 1) * 100
     data = cgScaleVector(cgdemodata_makey(101, 5, Seed=seed) * scale[0], 0, 100)
     END

 17: BEGIN

        ; Random 401 by 401 array.

     data = cgdemodata_makez(401, 401, 41, Seed=seed)
     data = Hist_Equal(data)
     data = BytScl(data, Top=!D.Table_Size-1)


     END

 18: BEGIN
     file = FILEPATH(SUBDIR=['examples', 'data'], 'elev_t.jpg')
     Read_JPEG, file, data
     END

 19: BEGIN
     file = FILEPATH(SUBDIR=['examples', 'data'], 'endocell.jpg')
     Read_JPEG, file, data
     END

 20: BEGIN
     file = FILEPATH(SUBDIR=['examples', 'data'], 'rbcells.jpg')
     Read_JPEG, file, data
     END

 21: BEGIN
     file = FILEPATH(SUBDIR=['examples', 'data'], 'muscle.jpg')
     Read_JPEG, file, data
     END

 22: BEGIN
     file = FILEPATH(SUBDIR=['examples', 'data'], 'image.tif')
     data = Read_TIFF(file)
     END


 23: BEGIN
     file = FILEPATH(SUBDIR=['examples', 'data'], 'mr_knee.dcm')
     data = Read_DICOM(file)
     data = Reverse(data,2)
     END

 24: BEGIN
     file = FILEPATH(SUBDIR=['examples', 'data'], 'mineral.png')
     data = Read_PNG(file)
     END
     
25: BEGIN ; 2D Gaussian.
    cgDemoData_Gauss2D, 101, 101, 70, 70, 20., array1
    cgDemoData_Gauss2D, 101, 101, 20, 20, 90., array2
    data = (array1 + array2) * 10.
    END


ELSE: ok = Dialog_Message("No data set with that index number. Sorry.")

ENDCASE

RETURN, data
END
;------------------------------------------------------------------------------



;+
; Reads the data set from its current location.
; 
; :Params:
;    event: in, required, type=structure
;        The event handler for the graphical user interface.
;-
PRO cgDemoData_EVENT, event
WIDGET_CONTROL, event.top, GET_UVALUE=ptr
WIDGET_CONTROL, event.id, GET_UVALUE=indexValue
*ptr = cgDemoData_ReadData(indexValue(event.index))
WIDGET_CONTROL, event.top, /DESTROY
END
;------------------------------------------------------------------


;+
; Select a dataset either interactively or by selection.
; 
; :Params:
; 
;    selection: in, optional, type=integer
;       The data set selection number. If not present, a graphical user
;       interface is presented to the user so that a data set may be
;       selected.
;       
; :Keywords:
;    cancel: out, optional, type=boolean
;       If a graphical user interface is used for the data selection, this output 
;       keyword is set to 1 if the user clicks the CANCEL button. Otherwise, it is 
;       set to 0.
;    group_leader: in, optional, type=long
;       The identifier of a widget group leader for this widget application. If the
;       group leader dies, this program will die as well.
;    images: in, optional, type=boolean, default=0
;       Set this keyword if you wish to see only 2D images in the selection widget.
;-
FUNCTION cgDemoData, selection, $
   CANCEL=cancel, $
   GROUP_LEADER=groupleader, $
   IMAGES=images

On_Error, 1

; Function to read and return training data sets.

COMMON cgDemoData_SEED, seed

   ; If a parameter is passed in, read that data set and return.

IF N_Params() EQ 1 THEN BEGIN
   type = Size(selection)
   type = type( type(0) + 1 )
   IF type EQ 0 THEN Message, 'Supplied argument is undefined.'
   IF type GT 5 THEN Message, 'Supplied argument must be a number.'
   selection = selection - 1
   selection = 0 > selection < 25
   data = cgDemoData_ReadData(selection)
   RETURN, data
ENDIF

IF Keyword_Set(images) THEN BEGIN

   value = ['Galaxy -- (BYTE 256-by-256 array)', $
            'CT Scan Thoracic Cavity -- (BYTE 256-by-256 array)', $
            'World Elevation Data -- (BYTE 360-by-360 array)', $
            'Brain X-Ray -- (BYTE 512-by-512 array)', $
            'Earth Mantle Convection -- (BYTE 248-by-248 array)', $
            'M51 Whirlpool Galaxy -- (BYTE 340-by-440 array)', $
            'Hurricane Gilbert -- (BYTE 440-by-340 array)', $
            'Random Image Array -- (BYTE 400-by-400)', $
            'Endocell (JPEG 615-by-416 2D BYTE array)', $
            'Red Blood Cells (JPEG 432-by-389 2D BYTE array)', $
            'Muscle (JPEG 652-by-444 2D BYTE array)', $
            'River Delta (TIFF 786-by-512 2D BYTE array)', $
            'MRI of Knee (DICOM 256-by-256 2D INT array)', $
            'Mineral Micrograph (PNG 288-by-216 2D BYTE array)']

   indexValue = [3,4,6,8,10,11,12,17,19,20,21,22,23,24]   ; The data sets.
   listsize = 14
   title = 'Select 2D Image...'

ENDIF ELSE BEGIN

   value = [' 1. Time Series Data (FLOAT 101 vector)', $
            ' 2. Elevation Data (FLOAT 41-by-41 array)', $
            ' 3. Snow Pack Data (FLOAT 41-by-41 array)', $
            ' 4. Galaxy (BYTE 256-by-256 array)', $
            ' 5. CT Scan Thoracic Cavity (BYTE 256-by-256 array)', $
            ' 6. Heart Gated Blood Pool Study (BYTE 64-by-64-by-15 array)', $
            ' 7. World Elevation Data (BYTE 360-by-360 array)', $
            ' 8. MRI Head Data (BYTE 80-by-100-by-57 array)', $
            ' 9. Brain X-Ray (BYTE 512-by-512 array)', $
            '10. Ali and Dave (192-by-192-by-2 array)', $
            '11. Earth Mantle Convection (BYTE 248-by-248 array)', $
            '12. M51 Whirlpool Galaxy (BYTE 340-by-440 array)', $
            '13. Hurricane Gilbert (BYTE 440-by-340 array)', $
            '14. Randomly Distributed (XYZ) Data (FLOAT 3-by-41 array)', $
            '15. Lat/Lon/Temperature Data Set (Structure)', $
            '16. Rose Data (24-bit JPEG image)', $
            '17. Random Data Vector (FLOAT 101 elements)', $
            '18. Random Image Array (BYTE 400-by-400)', $
            '19. Boulder Elevation Image (24-bit JPEG image)', $
            '20. Endocell (JPEG 615-by-416 2D BYTE array)', $
            '21. Red Blood Cells (JPEG 432-by-389 2D BYTE array)', $
            '22. Muscle (JPEG 652-by-444 2D BYTE array)', $
            '23. River Delta (TIFF 786-by-512 2D BYTE array)', $
            '24. MRI of Knee (DICOM 256-by-256 2D INT array)', $
            '25. Mineral Micrograph (PNG 288-by-216 2D BYTE array)', $
            '26. 2D Combined Gaussian (101-by-101 FLOAT array)']

   indexValue = IndGen(N_Elements(value))
   listsize = N_Elements(value)
   title = 'Select Data Set...'
ENDELSE

IF Keyword_Set(groupleader) THEN BEGIN
   tlb = WIDGET_BASE(TITLE=title, COLUMN=1, $
      GROUP_LEADER=groupleader, /MODAL)
ENDIF ELSE BEGIN
   tlb = WIDGET_BASE(TITLE=title, COLUMN=1)
ENDELSE

list = WIDGET_LIST(tlb, VALUE=value, SCR_XSIZE=400, YSIZE=listsize, UValue=indexValue)
button = WIDGET_BUTTON(tlb, VALUE='Cancel', EVENT_PRO='cgDemoData_CANCEL')
cgCenterTLB, tlb
WIDGET_CONTROL, tlb, /REALIZE

   ; Create a pointer to store the data.

ptr = Ptr_New(-1)
WIDGET_CONTROL, tlb, SET_UVALUE=ptr


XMANAGER, 'cgDemoData', tlb

   ; Get the data if it is there. If it is not there,
   ; user canceled or error occured.

data = *ptr
IF N_Elements(data) LE 1 THEN BEGIN
   cancel = 1
   Ptr_Free, ptr
   RETURN, -1
ENDIF ELSE BEGIN
   cancel = 0
   Ptr_Free, ptr
   RETURN, data
ENDELSE
END