File: faq

package info (click to toggle)
ploticus-doc 2.33-1
  • links: PTS
  • area: main
  • in suites: etch, etch-m68k
  • size: 9,392 kB
  • ctags: 169
  • sloc: pascal: 469; makefile: 63; sh: 11
file content (1094 lines) | stat: -rw-r--r-- 22,669 bytes parent folder | download
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
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
.ig >>
<STYLE TYPE="text/css">
<!--
        A:link{text-decoration:none}
        A:visited{text-decoration:none}
        A:active{text-decoration:none}
        OL,UL,P,BODY,TD,TR,TH,FORM { font-family: arial,helvetica,sans-serif;; font-size:small; color: #333333; }

        H1 { font-size: x-large; font-family: arial,helvetica,sans-serif; }
        H2 { font-size: large; font-family: arial,helvetica,sans-serif; }
        H3 { font-size: medium; font-family: arial,helvetica,sans-serif; }
        H4 { font-size: small; font-family: arial,helvetica,sans-serif; }
-->
</STYLE>
<title>ploticus: faq - frequently asked questions</title>
<body bgcolor=D0D0EE vlink=0000FF>
<br>
<br>
<center>
<table cellpadding=2 bgcolor=FFFFFF width=550><tr>
<td>
  <table cellpadding=2 width=550><tr>
  <td><br><h2>FAQ - frequently asked questions</h2></td>
  <td align=right>
  <small>
  <a href="../doc/welcome.html"><img src="../doc/ploticus.gif" border=0></a><br>
  Version 2.33 Jun'06
  <td></tr></table>
</td></tr>
<td>
<br>
<br>
.>>

.TH FAQ_-_frequently_asked_questions PL "02-JUN-2006   PL ploticus.sourceforge.net"
 
.LP
.ig >>
<center><table bgcolor=FFFFEC border=1 cellpadding=4><tr><td>
<font size=+1>
<ul>
<li><a href="#general">General</a>
<li><a href="#intl">Character sets and international support</a>
<li><a href="#scripts101">For script writers</a>
<li><a href="#filter">Filter solutions</a>
</font>
</td></tr></table></center>
.>>

.ig >>
<br><br><br>
.>>

.LP
Some basic introductory questions are now addressed on the
.ig >>
<a href="welcome.html">
.>>
\0ploticus home page.
.ig >>
</a>
.>>
Items that are new for version 2.30 are marked as
.ig >>
<img src="../gallery/gif/new.gif">
.>>


.ig >>
<a name=general></a>
.>>

.ig >>
<br><br><br>
.>>
.LP
\fBIs there an interactive mode?\fR
.IP \0 
No, the main thrust has been to develop an engine
that can produce graphics non-interactively, so that
it can be run in an automated, unattended way.



.ig >>
<br><br><br>
.>>
.LP
\fBWhat is ploticus good for?\fR
.IP \0 
Ploticus is good at making the types of 2-D graphs that you would see in
journals for medical and social sciences, 
newspapers and news magazines, business publications, and so on.
Ploticus is good for automated or just-in-time graph generation, handles date and time 
data nicely, and has basic statistical capabilities. It allows significant user control 
over colors, styles, options and details.


.ig >>
<br><br><br>
.>>
.LP
\fBWhat is ploticus not good for?\fR
.IP \0 
Ploticus is not a function plotting package; it has scant support for
mathematical formulas, scientific notations, or inline font or point size changes.
You can't plot binary data with ploticus.
There are no 3-D types of plots such as contours.
Ploticus is not a "marketing" graphics package, and
"chartjunk" effects, clip-art, gradient backgrounds, and so on have been intentionally avoided.

.ig >>
<br><br><br>
.>>
.LP
.ig >>
<img src="../gallery/gif/new.gif">
.>>
\fBI see there are two possible approaches: prefabs vs. scripts.  Compare and contrast?
If I start out using prefabs will it be difficult to transition to scripts?\fR
.IP \0
For both approaches you use the 
.ig >>
<a href="pl.1.html">
.>>
\0pl command
.ig >>
</a>
.>>
(or C programmers can use the 
.ig >>
<a href="api.html">
.>>
\0libploticus API).
.ig >>
</a>
.>>
For prefabs you use \fCpl -prefab \fIprefabname\fR \fC...\fR and for scripts you use
\fCpl \fIscriptfile\fR \fC...\fR
Prefabs are easier because all parameters are given on the command line.. everything else
uses reasonable (?) defaults.  The new \fC-drawdump\fR functionality makes prefabs more
powerful by allowing you to combine/overlay multiple pl runs into one graphic result.
Scripts are a lot more flexible but there's a bigger learning curve.
A recommended approach is to begin by prototyping with prefabs, then use the \fC-echo stdout\fR option to
dump out an equivalent script, then work from there.  This helps with transitioning from one to the other.
Prefabs are really just special, generalized scripts that can accept a lot of parameters.. but because of
this the prefab scripts should not really be the place where you learn how to write scripts.

.ig >>
<br><br><br>
.>>
.LP
\fBIs a "config file" the same thing as a "script file"?\fR
.IP \0 
No!  They are two different things!  If you think they're the same thing you will be confused
everywhere in the documentation!  Here's the difference: You create a
.ig >>
<a href="scripts.html">
.>>
\0script file
.ig >>
</a>
.>>
to tell ploticus how to draw a particular graph (axes, title, reading the data, plotting).  
On the other hand, you can create a
.ig >>
<a href="config.html">
.>>
\0config file
.ig >>
</a>
.>>
(if you want to) in order to get certain "environmental" settings in effect every time you run \fCpl\fR,
such as a default date format, international number notation or month names, and so on.  You can also the
config file \fCoption\fR directive to automatically set any
.ig >>
<a href="pl.1.html">
.>>
\0pl command line option
.ig >>
</a>
.>>
every time you run \fCpl\fR.


.ig >>
<br><br><br>
.>>
.LP
\fBWhat statistical capabilities does ploticus include?\fR
.IP \0 
Some.  There are capabilities for curve fitting,
computing linear regression, and Pearson correlation coefficient \fIr\fR.
There is a built-in facility (proc tabulate) for computing frequency
distributions.  Means, medians, quartiles, standard deviations, etc. may
be computed using proc processdata or proc rangebar.  

.ig >>
<br><br><br>
.>>
.LP
.ig >>
<img src="../gallery/gif/new.gif">
.>>
\fBIt would be nice if I could have ploticus process/manipulate my data so I don't have to invoke another program
to do this.\fR
.IP \0
Script writers can do a number of manipulations using
.ig >>
<a href="processdata.html">
.>>
\0proc processdata.
.ig >>
</a>
.>>
These capabilities are worth becoming familiar with.
Script writers can alter the format of the data on a row by row basis by using
.ig >>
<a href="getdata.html">
.>>
\0proc getdata's filter attribute.
.ig >>
</a>
.>>
If you just need to select certain rows from a data set, you can do this using \fCselect\fR
attribute when data are read, or when rendering a certain plot.


.ig >>
<br><br><br>
.>>
.LP
\fBCan I use ploticus as part of a commercial package or service?\fR
.IP \0 
This is possible.  
Please see the 
.ig >>
<a href="../doc/Copyright.html">
.>>
\0copyright page
.ig >>
</a>
.>>


.ig >>
<br><br><br>
.>>
.LP
\fBCan ploticus get data directly from MySQL, Oracle, Excel, Access, etc.?\fR
.IP \0 
Ploticus is not tightly integrated with these other environments.
You would need to dump data out into an ascii file first, or pipe the data and tell ploticus
to read from standard input.
Script writers can also invoke a shell command which generates data, such as this:
.nf
	#proc getdata
	  delim: tab
	  command: mysql ...
.fi

.ig >>
<br><br>
.>>

.LP
\fBWhat about large data sets?\fR
.IP \0 
The 
.ig >>
<a href="limits.html">
.>>
\0default capacities
.ig >>
</a>
.>>
are fairly large, and you can increase most of them using
command line capacity-setting arguments.
Another thing to consider (in scripts) is using
.ig >>
<a href="getdata.html">
.>>
\0proc getdata's
.ig >>
</a>
.>>
\fCselect\fR or \fCfilter\fR attributes to pare down the size as the data are being read.


.ig >>
<br><br><br>
.>>
.LP
\fBCan I import ploticus graphs into PowerPoint, Word, etc.?\fR
.IP \0 
Yes.  
PNG and GIF files may be inserted as pictures.
SVG has a bright future as a portable and scalable graphic format.
EPS files may be used with PowerPoint if the result will be
rendered on a PostScript film imager.




.ig >>
<br><br><br>
.>>
.LP
\fBHow can I enlarge or reduce my results?\fR
.IP \0 
Use the \fB-scale\fR command line option.


.LP
\fBHow can I make thumbnails?\fR
.IP \0 
Just use a small scale factor, such as \fB-scale 0.3\fR.
Very small text is rendered as lines automatically.

.LP
\fBHow can I crop my results?\fR
.IP \0 
Use one of the \fB-crop\fR, \fB-croprel\fR or \fB-tightcrop\fR command line options.

.LP
\fB-tightcrop is close to what I want but it is cropping too closely on one side.\fR
.IP \0 
Try \fB-croprel\fR.

.ig >>
<br><br><br>
.>>
.LP
.ig >>
<img src="../gallery/gif/new.gif">
.>>
\fBI've found a couple of ploticus prefab commands that do what I want.. is there any way
to combine them all into one output image?\fR
.IP \0
Yes, as of 2.30 you can combine the result of any number of \fCpl\fR invocations into one
output result.
.ig >>
<a href="prefabs.html#drawdump">
.>>
\0Here's how to do this.
.ig >>
</a>
.>>


.ig >>
<br><br><br>
.>>

.LP
\fBI have a program that generates a stream of
X Y coordinates to create a special display.  How can I
display my results via Ploticus?\fR
.IP \0 
If you can process your stream so that it becomes a stream of ploticus draw commands, you can use the
.ig >>
<a href="prefab_draw.html">
.>>
\0draw prefab
.ig >>
</a>
.>>
to render on any device ploticus supports.

.ig >>
<br><br><br>
.>>
.LP
\fBHow can I do cross-hatch fill for my bar graph?\fR
.IP \0 
Hatch patterns are also available as a 
.ig >>
<a href="color.html">
.>>
\0color option
.ig >>
</a>
.>>
which may be useful in getting more distinguishable bar shades.
Hatch patterns may only be used to fill rectangular areas such as bars.
They can't be used for pie graphs.

.ig >>
<br><br><br>
.>>
.LP
\fBCan I render a transparent background?\fR
.IP \0
The special color name \fCtransparent\fR is available for use when generating images.
Last time I checked this worked with pseudo-GIF but not PNG output..


.ig >>
<br><br><br>
.>>
.LP
\fBI have large web log files.
I would like to plot a frequency distribution of number of hits per date and time,
What's the best way to do this?\fR
.IP \0 
Try the 
.ig >>
<a href="prefab_chron.html">
.>>
\0chron prefab
.ig >>
</a>
.>>
with \fBtabulate=yes\fR.
Script writers can also
use \fBproc processdata\fR with the \fBcount\fR action.
Your data will have to be sorted (or at least grouped) so that
all like datetimes are together.  A gallery example where this 
is done is
.ig >>
<a href="../gallery/hitcount.htm">
.>>
\0hitcount
.ig >>
</a>
.>>


.LP
.ig >>
<a name=intl></a>
<hr>
.>>
.ig >>
<br><br><br>
.>>
.SH Character sets and international support

.LP
.ig >>
<img src="../gallery/gif/new.gif">
.>>
\fBI need to render superscripts in my title and Y axis label.\fR
.IP \0
This is now supported in a limited implementation (2.30+).. 
.ig >>
<a href="fonts.html">
.>>
\0more info
.ig >>
</a>
.>>

.ig >>
<br><br><br>
.>>

.LP
\fBHow can I render a proper less-than-or-equal-to symbol, Portugese
characters, or other special symbols?\fR
.IP \0 
This is now described
.ig >>
<a href="fonts.html">
.>>
\0here
.ig >>
</a>
.>>



.ig >>
<br><br><br>
.>>
.LP
\fBWhat about support for UNICODE, BIG-5, etc.\fR
.IP \0 
Through SVG or Freetype2 (which can render unicode fonts),
Ploticus is able to render utf8-encoded unicode titles, labels, etc. 
.ig >>
<a href="fonts.html">
.>>
\0More info and an example
.ig >>
</a>
.>>


.ig >>
<br><br><br>
.>>
.LP
\fBI would like dates to use the German month abbreviations rather
than the English.\fR
.IP \0 
This is possible.  See
.ig >>
<a href="settings.html">
.>>
\0proc settings
.ig >>
</a>
.>>
or
.ig >>
<a href="config.html">
.>>
\0config files.
.ig >>
</a>
.>>


.ig >>
<br><br><br>
.>>
.LP
\fBIs there any way to get thousands separators so that large numbers are 
more readable e.g. 3,024,582? \fR
.IP \0 
Yes, see
.ig >>
<a href="settings.html">
.>>
\0proc settings
.ig >>
</a>
.>>
or
.ig >>
<a href="config.html">
.>>
\0config files.
.ig >>
</a>
.>>


.ig >>
<br><br><br>
.>>
.LP
\fBIs there a way to get European-style display of numbers, eg. comma used as
the decimal point, and period (.) used as the thousands separator?\fR
.IP \0 
Yes, see
.ig >>
<a href="settings.html">
.>>
\0proc settings
.ig >>
</a>
.>>
or
.ig >>
<a href="config.html">
.>>
\0config files.
.ig >>
</a>
.>>


.ig >>
<br><br><br>
.>>
.LP
\fBWhy isn't vertical text displayed properly on X11?\fR
.IP \0 
Ploticus doesn't store its own fonts or have its own 
font system; rather it uses fonts that are native to the various graphics platforms
or drivers.  X11 does not support vertical fonts (at least it didn't seem to
when I wrote the X11 code several years ago).  PostScript and PNG/GIF do support 
vertical fonts.


.ig >>
<br><br><br>
.>>
.LP
\fBIf I had one feature request for ploticus it would be
support for setting text at angles other than 0 and 90.\fR
.IP \0  
This could be done for postscript rendering easily enough
but would be difficult in X11 and PNG/GIF, since the underlying
libraries do not support angled fonts.

.ig >>
<br><br><br>
.>>
.LP
.ig >>
<img src="../gallery/gif/new.gif">
.>>
\fBPloticus EPS files don't seem to work with other utility programs 
I'm using.  Is something wrong with them?\fR
.IP \0
Ploticus EPS files conform to the spec as far as I know.
One thing to try would be to turn off the latin1 encoding (see 
.ig >>
<a href="settings.html">
.>>
\0proc settings' ps_latin1_encoding attribute)
.ig >>
</a>
.>>

.LP

.ig >>
<br><br><br>
.>>
.ig >>
<hr>
<a name=scripts101></a>
.>>

.SH For script writers

.LP
\fBHow do I..\fR
.br
.ig >>
&nbsp; &nbsp;
.>>
\fB..perform arithmetic?\fR
.br
.ig >>
&nbsp; &nbsp;
.>>
\fB..take a substring?\fR
.br
.ig >>
&nbsp; &nbsp;
.>>
\fB..format a floating point number?\fR
.br
.ig >>
&nbsp; &nbsp;
.>>
\fB..access a particular cell in the data?\fR
.IP \0 
These tasks are all accomplished using functions.
Specifically, $arith(), $substring(), $formatfloat(), and $dataitem().
See the
.ig >>
<a href="functions.html">
.>>
\0functions documentation
.ig >>
</a>
.>>
for descriptions of the available functions, well worth getting familiar with.


.ig >>
<br><br><br>
.>>
.LP
\fBHow do I capture the results of a system command?\fR
.IP \0 
The following would execute the 'date' command and the results would be available
in ploticus variable @todaysdate:
.nf
  \0#shell #processrows 
  \0  date
  \0#endshell
  \0#call $shellrow( todaysdate )
.fi

.ig >>
<br><br><br>
.>>

.LP
\fBHow do I set up a loop?\fR
.IP \0 
Loops may be made to iterate over members of a
.ig >>
<a href="commalist.html">
.>>
\0commalist.
.ig >>
</a>
.>>
See gallery examples
.ig >>
<a href="../gallery/colorgrid.htm">
.>>
\0colorgrid
.ig >>
</a>
.>>
and
.ig >>
<a href="../gallery/lineplot20.htm">
.>>
\0lineplot20
.ig >>
</a>
.>>


.ig >>
<br><br><br>
.>>
.LP
\fBWhy does a double at-sign (@@) need to be used in "select"
attributes and in getdata filters?\fR
.IP \0 
The first at-sign is stripped off by the script evaluator.
These attributes require that one at-sign survive that step, hence
two must be supplied.



.ig >>
<br><br><br>
.>>
.LP
\fBWhat are #clone and #saveas and how do they work?\fR
.IP \0 
\fB#clone\fR and \fB#saveas\fR are used
when doing several similar plots, such as a set of four
bar graphs that have the same style.  \fB#saveas\fR saves
the attribute settings for one proc invocation.  \fB#clone\fR
uses a set of attribute settings that was saved earlier.
An example is
.ig >>
<a href="../gallery/volunteers.htm">
.>>
\0volunteers.
.ig >>
</a>
.>>
See also the
.ig >>
<a href="../doc/scriptsyntax.html">
.>>
\0scripts syntax page.
.ig >>
</a>
.>>


.ig >>
<br><br><br>
.>>
.LP
\fBMy page title has garbage at the end.\fR
.IP \0 
Attributes that are multi-line need to be terminated with a blank
line.  Perhaps the blank line was left out.



.ig >>
<br><br><br>
.>>
.LP
\fBPloticus seems to be ignoring an attribute I have set.\fR
.IP \0 
If the attribute in question follows a multi-line attribute,
you may have forgotten to terminate the multi-line attribute
with a blank line.


.ig >>
<br><br><br>
.>>
.LP
\fBAccording to the documentation, proc getdata sets a ploticus variable called NRECORDS to the number of
records read.  However I am having trouble accessing NRECORDS immediately after proc getdata.\fR
.IP \0 
Use \fB#endproc\fR to terminate your proc getdata block.
This is a side-effect of the way that ploticus parses scripts. 
\fB#endproc\fR is described in the
.ig >>
<a href="scripts.html">
.>>
\0introduction to scripts.
.ig >>
</a>
.>>


.ig >>
<br><br><br>
.>>
.LP
\fBI have a graph where I set up a plotting area using proc areadef,
proc yaxis, and two separate invocations of proc xaxis.  How do I
clone this entire plotting area several times?
.IP \0 
You need to use #saveas within every proc that is involved (with
different instance names), and then use #clone all of the procs.
There is no way to clone a set of procs together in one operation.


.ig >>
<br><br><br>
.>>
.LP
\fBHow do I render two separate scatter plots on the same plot area?  \fR
.IP \0 
1) Set up your plotting area; 2) read in your first data set; 3) do your first 
scatterplot; 4) read in your second data set; 5) do your second scatterplot.
The first areadef stays in effect until a new areadef is specified,
thus any number of plots may be rendered in the area.


.ig >>
<br><br><br>
.>>
.LP
\fBCan I make a Y axis on the right edge of the plot rather than the left?\fR
.IP \0 
Yes, see gallery example 
.ig >>
<a href="../gallery/sa12.htm">
.>>
\0sa12
.ig >>
</a>
.>>


.ig >>
<br><br><br>
.>>
.LP
\fBIs it possible to overlay two coordinate systems on one plot?\fR
.IP \0 
Yes, see gallery example 
.ig >>
<a href="../gallery/sa13.htm">
.>>
\0sa13
.ig >>
</a>
.>>
which overlays Celsius and Fahrenheit.


.ig >>
<br><br><br>
.>>
.LP
\fBHow can I have grid lines in orange every 0.1 unit, and then grid lines
in black every 1.0 unit?\fR
.IP \0 
Invoke #proc axis twice and overlay the two, to get more complex 
systems of grids, tics, and stubs.  See example
.ig >>
<a href="../gallery/sa14.htm">
.>>
\0sa14
.ig >>
</a>
.>>
which does this.


.ig >>
<br><br><br>
.>>
.LP
\fBHow can I make \fCautorange\fB work for stacked bars, clustered bars, or error bars?
.IP \0 
Use the
.ig >>
<a href="autorange.html">
.>>
\0autorange
.ig >>
</a>
.>>
\fCdatafields\fR attribute to specify the data fields, and set the \fCcombomode\fR attribute.
Combomode tells it whether to sum the fields or take an overall max.  
The prefab scripts stack.pl, lines.pl, and vbars.pl are examples.


.ig >>
<br><br><br>
.>>
.LP
\fBAn axis labelling question: my xrange goes from 0.5 to 12.  When I 
do stubs of "increment 1" they are drawn at 0.5, 1.5, 2.5, etc..  I want them to be
at 1.0, 2.0, etc.\fR
.IP \0 
Stub placement begins by default at the minima.  To override this, the stubrange
attribute can be used.  For your case, it would be: \fCstubrange: 1.0\fR


.ig >>
<br><br><br>
.>>
.LP
\fBIs there a way to do a broken Y axis?\fR
.IP \0 
Yes, although broken axes cannot be done in an automated way.
See gallery example
.ig >>
<a href="../gallery/brokenaxis.htm">
.>>
\0brokenaxis
.ig >>
</a>
.>>
and the man page for
.ig >>
<a href="../doc/breakaxis.html">
.>>
\0proc breakaxis
.ig >>
</a>
.>>


.ig >>
<br><br><br>
.>>
.LP
\fBI am trying to do a plot where the X axis is dates expressed in quarter years
(quarters), to show quarterly results.  It is not coming out right.\fR
.IP \0 
It is a little bit tricky because data in quarter notation is converted
to a full date midpoint, so the X range needs to be expressed in a full date notation,
then you change units to quarter notation.  See the example
.ig >>
<a href="../gallery/quarters.htm">
.>>
\0quarters
.ig >>
</a>
.>>
which illustrates.



.ig >>
<br><br><br>
.>>
.LP
\fBIs there any way to make an axis progress from a large value to a small value?\fR
.IP \0 
Yes, although it is not entirely straighforward.
See gallery example
.ig >>
<a href="../gallery/hbars4.htm">
.>>
\0hbars4
.ig >>
</a>
.>>

.ig >>
<br><br><br>
.>>
.LP
.ig >>
<img src="../gallery/gif/new.gif">
.>>
\fBI need to automatically find the maxima of a field, and place an annotation there.\fR
.IP \0
Script writers can do this using
.ig >>
<a href="processdata.html">
.>>
\0proc processdata's
.ig >>
</a>
.>>
\fCaction: stats\fR (versions 2.30+) to set some ploticus variables,
which can then drive proc annotate location.

.ig >>
<br><br><br>
.>>
.LP
.ig >>
<img src="../gallery/gif/new.gif">
.>>
\fBI need to do a scatterplot where the X component is taken from certain data records,
and the Y component is taken from certain other records.\fR
.IP \0
Script writers can handle this using
.ig >>
<a href="processdata.html">
.>>
\0proc processdata's
.ig >>
</a>
.>>
\fCaction: join\fR (versions 2.30+).


.ig >>
<br><br><br>
.>>
.LP
\fB I have one data set with about 80 different cases represented in it.  Each case has
several dozen rows of data.  I want to produce a separate plot for each case.
What's the best way to do this?\fR
.IP \0 
Use the
.ig >>
<a href="processdata.html">
.>>
\0proc processdata
.ig >>
</a>
.>>
\fBbreaks\fR attribute.
It works within a loop, and causes the data set to be scanned only once.
It requires that the data be sorted by case.


.LP
.ig >>
<hr>
<a name=filter></a>
.>>

.ig >>
<br><br><br>
.>>
.SH FILTER SOLUTIONS
In scripts, when working with 
.ig >>
<a href="getdata.html">
.>>
\0proc getdata filters
.ig >>
</a>
.>>
it is good practice to set \fCshowresults: yes\fR so that you can see what you're doing during debugging.
.ig >>
<br><br><br>
.>>
.LP
\fBI have a data set with dates in field 2 and times in field 3.  
How can I plot these using the datetime scaling type?\fR
.IP \0 
Ploticus datetime values have the form \fIdate\fB.\fItime\fR.
The date and the time may in any of the supported notations.
The dot (.) separator is required.
You can use proc getdata's \fCfilter\fR attribute to concatentate fields
2 and 3 like this:
.nf
\0	#proc getdata
\0	file: mydata
\0	filter: ##print @@1 @@2.@@3 @@4 @@5
.fi


.LP 
\fBIn the results from sar -u, I can get "idle" time in %. Subtracting that
from 100 would give me the total CPU load data.  Is there an easy way to 
accomplish that within the ploticus script?\fR
.IP \0  
Yes, similarly to the above example, you can use proc getdata's filter attribute.
Suppose your idle time is in field #4:
.nf 
\0	#proc getdata
\0	file: myfile
\0	filter: ##set CPUTOT = $arith(100-@@4)
\0        	##print @@1 @@2 @@3 @@CPUTOT @@5 @@6
.fi



.ig >>
<br>
<br>
</td></tr>
<td align=right>
<a href="../doc/welcome.html">
<img src="../doc/ploticus.gif" border=0></a><br><small>data display engine &nbsp; <br>
<a href="../doc/Copyright.html">Copyright Steve Grubb</a>
<br>
<br>
<center>
<img src="../gallery/all.gif"> 
</center>
</td></tr>
</table>
<br>
<center>
Ploticus is hosted at http://ploticus.sourceforge.net <br>
<img src="http://sourceforge.net/sflogo.php?group_id=38453" width="88" height="31" border="0" alt="SourceForge Logo">
</center>
.>>