[OpenSPARC-T2-DV] / tools / perl-5.8.0 / lib / site_perl / 5.8.0 / sun4-solaris / Tk / demos / widtrib / plop.pl

# Plot a series of continuous functions on a Perl/Tk Canvas.
#
# This program is described in the Perl/Tk column from Volume 1, Issue 1 of
# The Perl Journal (http://tpj.com/tpj), and is included in the Perl/Tk
# distribution with permission.  It has been modified slightly to conform
# to the widget demo standard.

#!/usr/local/bin/perl -w
#
# plot_program - plot a series of continuous functions on a Perl/Tk Canvas.
#
# Stephen O. Lidie, Lehigh University Computing Center, lusol@Lehigh.EDU
# 96/01/27.
#
# Copyright (C) 1996 - 1998 Stephen O. Lidie. All rights reserved.
#
# This program is free software; you can redistribute it and/or modify it under
# the same terms as Perl itself.

require 5.002;
use strict;
use Tk;
use Tk::Dialog;
use Tk::LabEntry;
eval {require "plop.fnc";};	# user supplied math functions

# Predeclare global subroutines and variables.

sub collect_errors;
sub display_coordinates;
sub initialize_canvas;
sub initialize_dialogs;
sub initialize_functions;
sub initialize_menus;
sub make_menubutton;
sub plot_functions;
sub update_functions;

my $VERSION = '1.0';

# The default sample functions and limits, each in a different color.

my (@FUNCTIONS) = ('sin($x)', 'cos($x)', 'exp($x)', '$x', 'int($x)');
my (@COLORS) = qw(red green blue orange olivedrab magenta black salmon purple);
my $NUM_COLORS = scalar @COLORS;
my ($X_MIN, $X_MAX, $Y_MIN, $Y_MAX) = (-5, 5, -5, 5);
my ($DX, $DY) = ($X_MAX - $X_MIN, $Y_MAX - $Y_MIN);

# Declare constants that configure the plotting area: a square approximately
# 500 pixels on a side, with left/right and top/bottom margins of 80 pixles
# where we can paint axes labels.  With this layout there is a 340x340 area
# available for graphs.

my $MIN_PXL = 0;		# minimum Canvas pixel coordinate
my $MAX_PXL = 300;		# maximum Canvas pixel coordinate
my $MARGIN = 80;		# margin size, in pixels
my $ALEN = $MAX_PXL - 2 * $MARGIN; # X/Y axes length, in pixels

# Declare Perl/Tk widgets and other data.

my $CANV;			# Canvas widget used for plotting functions
my $DIALOG_ABOUT;		# Dialog widget showing "About" information
my $DIALOG_USAGE;		# Dialog widget describing plot usage
my $MBF;			# Menubutton frame
my $MW = MainWindow->new;	# program's main window
my $ORIGINAL_CURSOR = ($MW->configure(-cursor))[3]; # restore this cursor
my $TEXT;			# Text widget showing function definitions

# %ERRORS is a hash to collect eval() and -w errors.  The keys are the error
# messages themselves and the values are the number of times a particular
# error was detected.

my %ERRORS;

# Begin main.

initialize_dialogs;
initialize_menus;
initialize_canvas;
initialize_functions;

# End main.

sub collect_errors {

    # Update the hash %ERRORS with the latest eval() error message.  Remove
    # the eval() line number (it's useless to us) to maintain a compact hash.
    
    my($error) = @_;

    $error =~ s/eval\s+(\d+)/eval/;
    $ERRORS{$error}++;

} # end collect_errors

sub display_coordinates {

    # Print Canvas and Plot coordinates.

    my($canvas) = @_;

    my $e = $canvas->XEvent;
    my($canv_x, $canv_y) = ($e->x, $e->y); 
    my($x, $y);
    $x = $X_MIN + $DX * (($canv_x - $MARGIN) / $ALEN);
    $y = $Y_MAX - $DY * (($canv_y - $MARGIN) / $ALEN);
    print STDOUT "\nCanvas x = $canv_x, Canvas y = $canv_y.\n";
    print STDOUT  "Plot x = $x, Plot y = $y.\n";

} # end display_coordinates

sub initialize_canvas {

    # Create the Canvas widget and draw axes and labels.

    my($label_offset, $tick_length) = (20, 5);

    $CANV = $MW->Canvas(
			-width  => $MAX_PXL + $MARGIN * 2, 
			-height => $MAX_PXL, 
			-relief => 'sunken',
			);
    $CANV->pack;
    $CANV->Tk::bind('<Button-1>' => \&display_coordinates);

    $CANV->create('text', 
		  225, 25, 
		  -text => 'Plot Continuous Functions Of The Form y=f($x)',
		  -fill => 'blue',
		  );

    # Create the line to represent the X axis and label it.  Then label the
    # minimum and maximum X values and draw tick marks to indicate where they
    # fall.  The axis limits are LabEntry widgets embedded in Canvas windows.

    $CANV->create('line',
		  $MIN_PXL + $MARGIN, $MAX_PXL - $MARGIN, 
		  $MAX_PXL - $MARGIN, $MAX_PXL - $MARGIN,
		  );

    $CANV->create('window',
		  $MIN_PXL + $MARGIN, $MAX_PXL - $label_offset,
		  -window => $MW->LabEntry(
					   -textvariable => \$X_MIN,
					   -label => 'X Minimum',
					   -width => 5,
					   ),
		  );
    $CANV->create('line', 
		  $MIN_PXL + $MARGIN, $MAX_PXL - $MARGIN - $tick_length,
		  $MIN_PXL + $MARGIN, $MAX_PXL - $MARGIN + $tick_length,
		  );

    $CANV->create('window', 
		  $MAX_PXL - $MARGIN, $MAX_PXL - $label_offset,
		  -window => $MW->LabEntry(
					   -textvariable => \$X_MAX,
					   -label => 'X Maximum',
					   -width => 5,
					   ),
		  );
    $CANV->create('line', 
		  $MAX_PXL - $MARGIN, $MAX_PXL - $MARGIN - $tick_length,
		  $MAX_PXL - $MARGIN, $MAX_PXL - $MARGIN + $tick_length,
		  );

    # Create the line to represent the Y axis and label it.  Then label the 
    # minimum and maximum Y values and draw tick marks to indicate where they
    # fall.  The axis limits are LabEntry widgets embedded in Canvas windows.

    $CANV->create('line', 
		  $MAX_PXL - $MARGIN, $MIN_PXL + $MARGIN, 
		  $MAX_PXL - $MARGIN, $MAX_PXL - $MARGIN,
		  );

    $CANV->create('window', 
		  $MAX_PXL + $label_offset, $MIN_PXL + $MARGIN,
		  -window => $MW->LabEntry(
					   -textvariable => \$Y_MAX,
					   -label => 'Y Maximum',
					   -width => 5,
					   ),
		  );
    $CANV->create('line', 
		  $MAX_PXL - $MARGIN - $tick_length, $MIN_PXL + $MARGIN,
		  $MAX_PXL - $MARGIN + $tick_length, $MIN_PXL + $MARGIN,
		  );

    $CANV->create('window', 
		  $MAX_PXL + $label_offset, $MAX_PXL - $MARGIN,
		  -window => $MW->LabEntry(
					   -textvariable => \$Y_MIN,
					   -label => 'Y Minimum',
					   -width => 5,
					   ),
		  );
    $CANV->create('line', 
		  $MAX_PXL - $MARGIN - $tick_length, $MAX_PXL - $MARGIN,
		  $MAX_PXL - $MARGIN + $tick_length, $MAX_PXL - $MARGIN,
		  );

} # end initialize_canvas

sub initialize_dialogs {

    # Create all application Dialog objects.

    $DIALOG_ABOUT = $MW->Dialog(
				-title   => 'About',
				-text    => 
"plot_program $VERSION\n\n95/12/04\n\nThis program is described in the Perl/Tk column from Volume 1, Issue 1 of The Perl Journal (http://tpj.com/tpj), and is included in the Perl/Tk distribution with permission.",
				-bitmap  => 'info',
				-buttons => ['Dismiss'],
				);
    $DIALOG_ABOUT->configure(-wraplength => '6i');
    $DIALOG_USAGE = $MW->Dialog(
				-title   => 'Usage',
				-buttons => ['Dismiss'],
				);
    $DIALOG_USAGE->Subwidget('message')->configure(
						   -wraplength => '4i',
						   -text       => "plot_program iterates over the range of values X Minimum to X Maximum, setting the variable \$x to each value in turn, then evaluates each f(\$x) and paints a point on the Y axis.  The X axis increment is (Xmax - Xmin) / $ALEN.\n\nJust enter your functions in the Text widget and click the Plot button.\n\nYou can define a file named \"plop.fnc\" that contains additional private math functions, which is automatically \"require\"d by plot_program.  In this file are your private functions that you can plot.\n\nPressing button one on the pointing device displays on standard output the current canvas and plot X and Y coordinates.",
						   );

} # end initialize_dialogs

sub initialize_functions {

    # Pack a spacer Frame and then display instructions in a Label widget.

#    $MW->Frame(-height => 10)->pack;
    $MW->Label(
	       -text       => 'Enter your functions here',
	       -foreground => 'blue',
	       )->pack;

    # Create a Frame with a scrollable Text widget that displays the function
    # list, and a Button to initiate plot activities.

    my $functions_frame = $MW->Frame;
    $functions_frame->pack;
    $TEXT = $functions_frame->Text(-height => 3);
    $TEXT->pack;
    $functions_frame->AddScrollbars($TEXT);
    $functions_frame->configure(-scrollbars => 'e');
    update_functions;

    my $buttons_frame = $MW->Frame;
    $buttons_frame->pack(-padx => 10, -pady => 5, -expand => 1, -fill => 'x');
    my @pack_attributes = qw(-side left -fill x -expand 1);
    $buttons_frame->Button(
			   -text    => 'Plot', 
			   -command => \&plot_functions,
			   )->pack(@pack_attributes);

} # end initialize_functions

sub initialize_menus {

    # Create the Menubuttons and their associated Menu items.

    $MBF = $MW->Frame(-relief => 'raised', -borderwidth => 1);
    $MBF->pack(-fill => 'x');
	
    make_menubutton($MBF, 'File', 0, 'left',
		    [
		     ['Quit',  [$MW => 'bell'],          0],
		    ],
		   );
    make_menubutton($MBF, 'Help', 0, 'right',
		    [
		     ['About', [$DIALOG_ABOUT => 'Show'], 0],
		     ['',      undef,                     0],
		     ['Usage', [$DIALOG_USAGE => 'Show'], 0],
		    ],
		   );

} # end initialize_menus

sub make_menubutton {
	
    # Make a Menubutton widget; note that the Menu is automatically created.  
    # If the label is '', make a separator.

    my($mbf, $mb_label, $mb_label_underline, $pack, $mb_list_ref) = @_;

    my $mb = $mbf->Menubutton(
			       -text      => $mb_label, 
			       -underline => $mb_label_underline,
			      );
    my $mb_list;
    foreach $mb_list (@{$mb_list_ref}) {
	$mb_list->[0] eq '' ? $mb->separator :
	    $mb->command(
			 -label     => $mb_list->[0], 
			 -command   => $mb_list->[1], 
			 -underline => $mb_list->[2],
			 );
    }
    $mb->pack(-side => $pack);

} # end make_menubutton

sub plot_functions {

    # Plot all the functions.

    my($x, $y, $canv_x, $canv_y) = (0, 0, 0, 0);
    $canv_x = $MIN_PXL + $MARGIN; # X minimum
    $MW->configure(-cursor => 'watch');
    $DX = $X_MAX - $X_MIN;	# update delta X
    $DY = $Y_MAX - $Y_MIN;	# update delta Y
    $CANV->delete('plot');	# erase all previous plots
    
    # Fetch the newline-separated Text widget contents and update the function
    # list @FUNCTIONS.  Also update the Text widget with the new colors.

    @FUNCTIONS = ();
    foreach (split /\n/, $TEXT->get('0.0', 'end')) {
	next if $_ eq '';
	push @FUNCTIONS, $_;
    }
    update_functions;
    $MW->idletasks;

    %ERRORS = ();
    local $SIG{'__WARN__'} = sub {collect_errors($_[0])};

ALL_X_VALUES:
    for ($x = $X_MIN; $x <= $X_MAX; $x += ($X_MAX - $X_MIN) / $ALEN) {

      ALL_FUNCTIONS:
	foreach (0 .. $#FUNCTIONS) {
	    next if $FUNCTIONS[$_] =~ /^ERROR:/;
	    $y = eval $FUNCTIONS[$_];
	    if ($::EVAL_ERROR) {
		collect_errors($::EVAL_ERROR);
		next;
	    }
	    $canv_y = (($Y_MAX - $y) / $DY) * $ALEN + $MARGIN;
	    $CANV->create('text', $canv_x, $canv_y,
			  -fill => $COLORS[$_ % $NUM_COLORS],
			  -tags => ['plot'],
			  -text => '.',
			  ) if $canv_y > $MIN_PXL + $MARGIN and 
			       $canv_y < $MAX_PXL - $MARGIN;
	} # forend ALL_FUNCTIONS

	$canv_x++;		# next X pixel

    } # forend ALL_X_VALUES

    $MW->configure(-cursor => $ORIGINAL_CURSOR);
    $MW->idletasks;

    # Print all the eval() errors to alert the user of malformed functions.

    print STDOUT "\n" if %ERRORS;
    foreach (keys %ERRORS) {
	print STDOUT "$ERRORS{$_} occurrences of $_";
    }

} # end plot_functions

sub update_functions {

    # Insert the function list into the Text widget.

    $TEXT->delete('0.0', 'end');
    my $i = 0;
    foreach (@FUNCTIONS) {
	$TEXT->insert('end', "$_\n", [$i]);
	$TEXT->tagConfigure($i,
		   -foreground => $COLORS[$i % $NUM_COLORS],
		   -font       => 'fixed',
		   );
	$i++;
    }
    $TEXT->yview('end');

} # end update_function_list
Commit	Line	Data
86530b38 AT	1	# Plot a series of continuous functions on a Perl/Tk Canvas.
	2	#
	3	# This program is described in the Perl/Tk column from Volume 1, Issue 1 of
	4	# The Perl Journal (http://tpj.com/tpj), and is included in the Perl/Tk
	5	# distribution with permission. It has been modified slightly to conform
	6	# to the widget demo standard.
	7
	8	#!/usr/local/bin/perl -w
	9	#
	10	# plot_program - plot a series of continuous functions on a Perl/Tk Canvas.
	11	#
	12	# Stephen O. Lidie, Lehigh University Computing Center, lusol@Lehigh.EDU
	13	# 96/01/27.
	14	#
	15	# Copyright (C) 1996 - 1998 Stephen O. Lidie. All rights reserved.
	16	#
	17	# This program is free software; you can redistribute it and/or modify it under
	18	# the same terms as Perl itself.
	19
	20	require 5.002;
	21	use strict;
	22	use Tk;
	23	use Tk::Dialog;
	24	use Tk::LabEntry;
	25	eval {require "plop.fnc";}; # user supplied math functions
	26
	27	# Predeclare global subroutines and variables.
	28
	29	sub collect_errors;
	30	sub display_coordinates;
	31	sub initialize_canvas;
	32	sub initialize_dialogs;
	33	sub initialize_functions;
	34	sub initialize_menus;
	35	sub make_menubutton;
	36	sub plot_functions;
	37	sub update_functions;
	38
	39	my $VERSION = '1.0';
	40
	41	# The default sample functions and limits, each in a different color.
	42
	43	my (@FUNCTIONS) = ('sin($x)', 'cos($x)', 'exp($x)', '$x', 'int($x)');
	44	my (@COLORS) = qw(red green blue orange olivedrab magenta black salmon purple);
	45	my $NUM_COLORS = scalar @COLORS;
	46	my ($X_MIN, $X_MAX, $Y_MIN, $Y_MAX) = (-5, 5, -5, 5);
	47	my ($DX, $DY) = ($X_MAX - $X_MIN, $Y_MAX - $Y_MIN);
	48
	49	# Declare constants that configure the plotting area: a square approximately
	50	# 500 pixels on a side, with left/right and top/bottom margins of 80 pixles
	51	# where we can paint axes labels. With this layout there is a 340x340 area
	52	# available for graphs.
	53
	54	my $MIN_PXL = 0; # minimum Canvas pixel coordinate
	55	my $MAX_PXL = 300; # maximum Canvas pixel coordinate
	56	my $MARGIN = 80; # margin size, in pixels
	57	my $ALEN = $MAX_PXL - 2 * $MARGIN; # X/Y axes length, in pixels
	58
	59	# Declare Perl/Tk widgets and other data.
	60
	61	my $CANV; # Canvas widget used for plotting functions
	62	my $DIALOG_ABOUT; # Dialog widget showing "About" information
	63	my $DIALOG_USAGE; # Dialog widget describing plot usage
	64	my $MBF; # Menubutton frame
65	my $MW = MainWindow->new; # program's main window
66	my $ORIGINAL_CURSOR = ($MW->configure(-cursor))[3]; # restore this cursor
67	my $TEXT; # Text widget showing function definitions
68
69	# %ERRORS is a hash to collect eval() and -w errors. The keys are the error
70	# messages themselves and the values are the number of times a particular
71	# error was detected.
72
73	my %ERRORS;
74
75	# Begin main.
76
77	initialize_dialogs;
78	initialize_menus;
79	initialize_canvas;
80	initialize_functions;
81
82	# End main.
83
84	sub collect_errors {
85
86	# Update the hash %ERRORS with the latest eval() error message. Remove
87	# the eval() line number (it's useless to us) to maintain a compact hash.
88
89	my($error) = @_;
90
91	$error =~ s/eval\s+(\d+)/eval/;
92	$ERRORS{$error}++;
93
94	} # end collect_errors
95
96	sub display_coordinates {
97
98	# Print Canvas and Plot coordinates.
99
100	my($canvas) = @_;
101
102	my $e = $canvas->XEvent;
103	my($canv_x, $canv_y) = ($e->x, $e->y);
104	my($x, $y);
105	$x = $X_MIN + $DX * (($canv_x - $MARGIN) / $ALEN);
106	$y = $Y_MAX - $DY * (($canv_y - $MARGIN) / $ALEN);
107	print STDOUT "\nCanvas x = $canv_x, Canvas y = $canv_y.\n";
108	print STDOUT "Plot x = $x, Plot y = $y.\n";
109
110	} # end display_coordinates
111
112	sub initialize_canvas {
113
114	# Create the Canvas widget and draw axes and labels.
115
116	my($label_offset, $tick_length) = (20, 5);
117
118	$CANV = $MW->Canvas(
119	-width => $MAX_PXL + $MARGIN * 2,
120	-height => $MAX_PXL,
121	-relief => 'sunken',
122	);
123	$CANV->pack;
124	$CANV->Tk::bind('<Button-1>' => \&display_coordinates);
125
126	$CANV->create('text',
127	225, 25,
128	-text => 'Plot Continuous Functions Of The Form y=f($x)',
129	-fill => 'blue',
130	);
131
132	# Create the line to represent the X axis and label it. Then label the
133	# minimum and maximum X values and draw tick marks to indicate where they
134	# fall. The axis limits are LabEntry widgets embedded in Canvas windows.
135
136	$CANV->create('line',
137	$MIN_PXL + $MARGIN, $MAX_PXL - $MARGIN,
138	$MAX_PXL - $MARGIN, $MAX_PXL - $MARGIN,
139	);
140
141	$CANV->create('window',
142	$MIN_PXL + $MARGIN, $MAX_PXL - $label_offset,
143	-window => $MW->LabEntry(
144	-textvariable => \$X_MIN,
145	-label => 'X Minimum',
146	-width => 5,
147	),
148	);
149	$CANV->create('line',
150	$MIN_PXL + $MARGIN, $MAX_PXL - $MARGIN - $tick_length,
151	$MIN_PXL + $MARGIN, $MAX_PXL - $MARGIN + $tick_length,
152	);
153
154	$CANV->create('window',
155	$MAX_PXL - $MARGIN, $MAX_PXL - $label_offset,
156	-window => $MW->LabEntry(
157	-textvariable => \$X_MAX,
158	-label => 'X Maximum',
159	-width => 5,
160	),
161	);
162	$CANV->create('line',
163	$MAX_PXL - $MARGIN, $MAX_PXL - $MARGIN - $tick_length,
164	$MAX_PXL - $MARGIN, $MAX_PXL - $MARGIN + $tick_length,
165	);
166
167	# Create the line to represent the Y axis and label it. Then label the
168	# minimum and maximum Y values and draw tick marks to indicate where they
169	# fall. The axis limits are LabEntry widgets embedded in Canvas windows.
170
171	$CANV->create('line',
172	$MAX_PXL - $MARGIN, $MIN_PXL + $MARGIN,
173	$MAX_PXL - $MARGIN, $MAX_PXL - $MARGIN,
174	);
175
176	$CANV->create('window',
177	$MAX_PXL + $label_offset, $MIN_PXL + $MARGIN,
178	-window => $MW->LabEntry(
179	-textvariable => \$Y_MAX,
180	-label => 'Y Maximum',
181	-width => 5,
182	),
183	);
184	$CANV->create('line',
185	$MAX_PXL - $MARGIN - $tick_length, $MIN_PXL + $MARGIN,
186	$MAX_PXL - $MARGIN + $tick_length, $MIN_PXL + $MARGIN,
187	);
188
189	$CANV->create('window',
190	$MAX_PXL + $label_offset, $MAX_PXL - $MARGIN,
191	-window => $MW->LabEntry(
192	-textvariable => \$Y_MIN,
193	-label => 'Y Minimum',
194	-width => 5,
195	),
196	);
197	$CANV->create('line',
198	$MAX_PXL - $MARGIN - $tick_length, $MAX_PXL - $MARGIN,
199	$MAX_PXL - $MARGIN + $tick_length, $MAX_PXL - $MARGIN,
200	);
201
202	} # end initialize_canvas
203
204	sub initialize_dialogs {
205
206	# Create all application Dialog objects.
207
208	$DIALOG_ABOUT = $MW->Dialog(
209	-title => 'About',
210	-text =>
211	"plot_program $VERSION\n\n95/12/04\n\nThis program is described in the Perl/Tk column from Volume 1, Issue 1 of The Perl Journal (http://tpj.com/tpj), and is included in the Perl/Tk distribution with permission.",
212	-bitmap => 'info',
213	-buttons => ['Dismiss'],
214	);
215	$DIALOG_ABOUT->configure(-wraplength => '6i');
216	$DIALOG_USAGE = $MW->Dialog(
217	-title => 'Usage',
218	-buttons => ['Dismiss'],
219	);
220	$DIALOG_USAGE->Subwidget('message')->configure(
221	-wraplength => '4i',
222	-text => "plot_program iterates over the range of values X Minimum to X Maximum, setting the variable \$x to each value in turn, then evaluates each f(\$x) and paints a point on the Y axis. The X axis increment is (Xmax - Xmin) / $ALEN.\n\nJust enter your functions in the Text widget and click the Plot button.\n\nYou can define a file named \"plop.fnc\" that contains additional private math functions, which is automatically \"require\"d by plot_program. In this file are your private functions that you can plot.\n\nPressing button one on the pointing device displays on standard output the current canvas and plot X and Y coordinates.",
223	);
224
225	} # end initialize_dialogs
226
227	sub initialize_functions {
228
229	# Pack a spacer Frame and then display instructions in a Label widget.
230
231	# $MW->Frame(-height => 10)->pack;
232	$MW->Label(
233	-text => 'Enter your functions here',
234	-foreground => 'blue',
235	)->pack;
236
237	# Create a Frame with a scrollable Text widget that displays the function
238	# list, and a Button to initiate plot activities.
239
240	my $functions_frame = $MW->Frame;
241	$functions_frame->pack;
242	$TEXT = $functions_frame->Text(-height => 3);
243	$TEXT->pack;
244	$functions_frame->AddScrollbars($TEXT);
245	$functions_frame->configure(-scrollbars => 'e');
246	update_functions;
247
248	my $buttons_frame = $MW->Frame;
249	$buttons_frame->pack(-padx => 10, -pady => 5, -expand => 1, -fill => 'x');
250	my @pack_attributes = qw(-side left -fill x -expand 1);
251	$buttons_frame->Button(
252	-text => 'Plot',
253	-command => \&plot_functions,
254	)->pack(@pack_attributes);
255
256	} # end initialize_functions
257
258	sub initialize_menus {
259
260	# Create the Menubuttons and their associated Menu items.
261
262	$MBF = $MW->Frame(-relief => 'raised', -borderwidth => 1);
263	$MBF->pack(-fill => 'x');
264
265	make_menubutton($MBF, 'File', 0, 'left',
266	[
267	['Quit', [$MW => 'bell'], 0],
268	],
269	);
270	make_menubutton($MBF, 'Help', 0, 'right',
271	[
272	['About', [$DIALOG_ABOUT => 'Show'], 0],
273	['', undef, 0],
274	['Usage', [$DIALOG_USAGE => 'Show'], 0],
275	],
276	);
277
278	} # end initialize_menus
279
280	sub make_menubutton {
281
282	# Make a Menubutton widget; note that the Menu is automatically created.
283	# If the label is '', make a separator.
284
285	my($mbf, $mb_label, $mb_label_underline, $pack, $mb_list_ref) = @_;
286
287	my $mb = $mbf->Menubutton(
288	-text => $mb_label,
289	-underline => $mb_label_underline,
290	);
291	my $mb_list;
292	foreach $mb_list (@{$mb_list_ref}) {
293	$mb_list->[0] eq '' ? $mb->separator :
294	$mb->command(
295	-label => $mb_list->[0],
296	-command => $mb_list->[1],
297	-underline => $mb_list->[2],
298	);
299	}
300	$mb->pack(-side => $pack);
301
302	} # end make_menubutton
303
304	sub plot_functions {
305
306	# Plot all the functions.
307
308	my($x, $y, $canv_x, $canv_y) = (0, 0, 0, 0);
309	$canv_x = $MIN_PXL + $MARGIN; # X minimum
310	$MW->configure(-cursor => 'watch');
311	$DX = $X_MAX - $X_MIN; # update delta X
312	$DY = $Y_MAX - $Y_MIN; # update delta Y
313	$CANV->delete('plot'); # erase all previous plots
314
315	# Fetch the newline-separated Text widget contents and update the function
316	# list @FUNCTIONS. Also update the Text widget with the new colors.
317
318	@FUNCTIONS = ();
319	foreach (split /\n/, $TEXT->get('0.0', 'end')) {
320	next if $_ eq '';
321	push @FUNCTIONS, $_;
322	}
323	update_functions;
324	$MW->idletasks;
325
326	%ERRORS = ();
327	local $SIG{'__WARN__'} = sub {collect_errors($_[0])};
328
329	ALL_X_VALUES:
330	for ($x = $X_MIN; $x <= $X_MAX; $x += ($X_MAX - $X_MIN) / $ALEN) {
331
332	ALL_FUNCTIONS:
333	foreach (0 .. $#FUNCTIONS) {
334	next if $FUNCTIONS[$_] =~ /^ERROR:/;
335	$y = eval $FUNCTIONS[$_];
336	if ($::EVAL_ERROR) {
337	collect_errors($::EVAL_ERROR);
338	next;
339	}
340	$canv_y = (($Y_MAX - $y) / $DY) * $ALEN + $MARGIN;
341	$CANV->create('text', $canv_x, $canv_y,
342	-fill => $COLORS[$_ % $NUM_COLORS],
343	-tags => ['plot'],
344	-text => '.',
345	) if $canv_y > $MIN_PXL + $MARGIN and
346	$canv_y < $MAX_PXL - $MARGIN;
347	} # forend ALL_FUNCTIONS
348
349	$canv_x++; # next X pixel
350
351	} # forend ALL_X_VALUES
352
353	$MW->configure(-cursor => $ORIGINAL_CURSOR);
354	$MW->idletasks;
355
356	# Print all the eval() errors to alert the user of malformed functions.
357
358	print STDOUT "\n" if %ERRORS;
359	foreach (keys %ERRORS) {
360	print STDOUT "$ERRORS{$_} occurrences of $_";
361	}
362
363	} # end plot_functions
364
365	sub update_functions {
366
367	# Insert the function list into the Text widget.
368
369	$TEXT->delete('0.0', 'end');
370	my $i = 0;
371	foreach (@FUNCTIONS) {
372	$TEXT->insert('end', "$_\n", [$i]);
373	$TEXT->tagConfigure($i,
374	-foreground => $COLORS[$i % $NUM_COLORS],
375	-font => 'fixed',
376	);
377	$i++;
378	}
379	$TEXT->yview('end');
380
381	} # end update_function_list