1=head1 NAME 2 3Chart - a series of charting modules 4 5=head1 SYNOPSIS 6 7 use Chart::type; (type is one of: Points, Lines, Bars, LinesPoints, Composite, 8 StackedBars, Mountain, Pie, HorizontalBars, Split, ErrorBars, Pareto, Direction) 9 10 $obj = Chart::type->new; 11 $obj = Chart::type->new ( $png_width, $png_height ); 12 13 $obj->set ( $key_1, $val_1, ... ,$key_n, $val_n ); 14 $obj->set ( $key_1 => $val_1, 15 ... 16 $key_n => $val_n ); 17 $obj->set ( %hash ); 18 19 # GIFgraph.pm-style API to produce png formatted charts 20 @data = ( \@x_tick_labels, \@dataset1, ... , \@dataset_n ); 21 $obj->png ( "filename", \@data ); 22 $obj->png ( $filehandle, \@data ); 23 $obj->png ( FILEHANDLE, \@data ); 24 $obj->cgi_png ( \@data ); 25 26 # Graph.pm-style API 27 $obj->add_pt ($label, $val_1, ... , $val_n); 28 $obj->add_dataset ($val_1, ... , $val_n); 29 $obj->png ( "filename" ); 30 $obj->png ( $filehandle ); 31 $obj->png ( FILEHANDLE ); 32 $obj->cgi_png (); 33 34 The similar functions are available for j-peg 35 36 # Retrieve image map information 37 $obj->set ( 'imagemap' => 'true' ); 38 $imagemap_ref = $obj->imagemap_dump (); 39 40 41=head1 DESCRIPTION 42 43These man-pages give you the most important information about Chart. 44There is also a complete documentation (Documentation.pdf) within 45the Chart package. Look at it to get more information. 46This module is an attempt to build a general purpose graphing module 47that is easily modified and expanded. I borrowed most of the API 48from Martien Verbruggen's GIFgraph module. I liked most of GIFgraph, 49but I thought it was to difficult to modify, and it was missing a few 50things that I needed, most notably legends. So I decided to write 51a new module from scratch, and I've designed it from the bottom up 52to be easy to modify. Like GIFgraph, Chart uses Lincoln Stein's GD 53module for all of its graphics primitives calls. 54 55=head2 use-ing Chart 56 57Okay, so you caught me. There's really no Chart::type module. 58All of the different chart types (Points, Lines, Bars, LinesPoints, 59Composite, StackedBars, Pie, Pareto, HorizontalBars, Split, ErrorBars, 60Direction and Mountain so far) are classes by themselves, each inheriting 61a bunch of methods from the Chart::Base class. Simply replace 62the word type with the type of chart you want and you're on your way. 63For example, 64 65 use Chart::Lines; 66 67would invoke the lines module. 68 69=head2 Getting an object 70 71The new method can either be called without arguments, in which 72case it returns an object with the default image size (400x300 pixels), 73or you can specify the width and height of the image. Just remember 74to replace type with the type of graph you want. For example, 75 76 $obj = Chart::Bars->new (600,400); 77 78would return a Chart::Bars object containing a 600x400 pixel 79image. New also initializes most of the default variables, which you 80can subsequently change with the set method. 81 82 83=head2 Setting different options 84 85This is where the fun begins. Set looks for a hash of keys and 86values. You can pass it a hash that you've already constructed, like 87 88 %hash = ('title' => 'Foo Bar'); 89 $obj->set (%hash); 90 91or you can try just constructing the hash inside the set call, like 92 93 $obj->set ('title' => 'Foo Bar'); 94 95The following are all of the currently supported options: 96 97=over 4 98 99=item 'transparent' 100 101Makes the background of the image transparent if set to 'true'. Useful 102for making web page images. Default is 'false'. 103 104=item 'png_border' 105 106Sets the number of pixels used as a border between the graph 107and the edges of the png/j-peg. Defaults to 10. 108 109=item 'graph_border' 110 111Sets the number of pixels used as a border between the title/labels 112and the actual graph within the png. Defaults to 10. 113 114=item 'text_space' 115 116Sets the amount of space left on the sides of text, to make it more 117readable. Defaults to 2. 118 119=item 'title' 120 121Tells GD graph what to use for the title of the graph. If empty, 122no title is drawn. It recognizes '\n' as a newline, and acts accordingly. 123Remember, if you want to use normal quotation marks instead of single 124quotation marks then you have to quote "\\n". Default is empty. 125 126=item 'sub_title' 127 128Write a sub-title under the title in smaller letters. 129 130=item 'x_label' 131 132Tells Chart what to use for the x-axis label. If empty, no label 133is drawn. Default is empty. 134 135=item 'y_label', 'y_label2' 136 137Tells Chart what to use for the y-axis labels. If empty, no label 138is drawn. Default is empty. 139 140=item 'legend' 141 142Specifies the placement of the legend. Valid values are 'left', 'right', 143'top', 'bottom'. Setting this to 'none' tells chart not to draw a 144legend. Default is 'right'. 145 146=item 'legend_labels' 147 148Sets the values for the labels for the different data sets. Should 149be assigned a reference to an array of labels. For example, 150 151 @labels = ('foo', 'bar'); 152 $obj->set ('legend_labels' => \@labels); 153 154Default is empty, in which case 'Dataset 1', 'Dataset 2', etc. are 155used as the labels. 156 157 158=item 'tick_len' 159 160Sets the length of the x- and y-ticks in pixels. Default is 4. 161 162=item 'x_ticks' 163 164Specifies how to draw the x-tick labels. Valid values are 'normal', 165'staggered' (staggers the labels vertically), and 'vertical' (the 166labels are draw upwards). Default is 'normal'. 167 168=item 'xy_plot' 169 170Forces Chart to plot a x-y-graph, which means, that the x-axis is also 171numeric if set to 'true'. Very useful for mathematical graphs. 172Works for Lines, Points, LinesPoints and ErrorBars. Split makes always a 173xy_plot. Defaults to 'false'. 174 175=item 'min_y_ticks' 176 177Sets the minimum number of y_ticks to draw when generating a scale. 178Default is 6, The minimum is 2. 179 180=item 'max_y_ticks' 181 182Sets the maximum number of y_ticks to draw when generating a scale. 183Default is 100. This limit is used to avoid plotting an unreasonable 184large number of ticks if non-round values are used for the min_val 185and max_val. 186 187The value for 'max_y_ticks' should be at least 5 times larger than 188'min_y_ticks'. 189 190=item 'max_x_ticks', 'min_x_ticks' 191 192Work similar as 'max_y_ticks' and 'min_y_ticks'. Of course, only for a 193xy_plot. 194 195=item 'integer_ticks_only' 196 197Specifies how to draw the x- and y-ticks: as floating point 198('false', '0') or as integer numbers ('true', 1). Default: 'false' 199 200=item 'skip_int_ticks' 201 202If 'integer_ticks_only' was set to 'true' the labels and ticks will 203be drawn every nth tick. Of course in horizontalBars it affects the 204x-axis. Default to 1, no skipping. 205 206=item 'precision' 207 208Sets the number of numerals after the decimal point. Affects in most 209cases the y-axis. But also the x-axis if 'xy_plot' was set and also 210the labels in a pie chart. Defaults to 3. 211 212=item 'max_val' 213 214Sets the maximum y-value on the graph, overriding the normal auto-scaling. 215Default is undef. 216 217=item 'min_val' 218 219Sets the minimum y-value on the graph, overriding the normal auto-scaling. 220Default is undef. 221 222Caution should be used when setting 'max_val' and 'min_val' to floating 223point or non-round numbers. This is because the scale must start & end 224on a tick, ticks must have round-number intervals, and include round 225numbers. 226 227Example: Suppose your data set has a range of 35-114 units. If you specify 228them as the 'min_val' & 'max_val', the y_axis will be plotted with 80 ticks 229every 1 unit.. If no 'min_val' & 'max_val', the system will auto scale the 230range to 30-120 with 10 ticks every 10 units. 231 232If the 'min_val' & 'max_val' are specified to excessive precision, they may 233be overridden by the system, plotting a maximum 'max_y_ticks' ticks. 234 235=item 'include_zero' 236 237If 'true', forces the y-axis to include zero if it is not in the dataset 238range. Default is 'false'. 239 240In general, it is better to use this, than to set the 'min_val' if that 241is all you want to achieve. 242 243=item 'pt_size' 244 245Sets the radius of the points (for Chart::Points, etc.) in pixels. 246Default is 18. 247 248=item 'brush_size' 249 250Sets the width of the lines (for Chart::Lines, etc.) in pixels. 251Default is 6. 252 253=item 'brushStyle' 254 255Sets the shape of points for Chart::Points, Chart::LinesPoints. 256The possibilities are 'FilledCircle', 'circle', 'donut', 257'OpenCircle', 'fatPlus', 'triangle', 'upsidedownTriangle', 258'square', 'hollowSquare', 'OpenRectangle', 'FilledDiamond', 259'OpenDiamond', 'Star', 'OpenStar'. 260Default: 'FilledCircle 261 262=item 'skip_x_ticks' 263 264Sets the number of x-ticks and x-tick labels to skip. (ie. 265if 'skip_x_ticks' was set to 4, Chart would draw every 4th x-tick 266and x-tick label). Default is undef. 267 268=item 'custom_x_ticks' 269 270Used in points, lines, linespoints, errorbars and bars charts, this option 271allows you to you to specify exactly which x-ticks and x-tick labels should 272be drawn. It should be assigned a reference to an array of desired 273ticks. Just remember that I'm counting from the 0th element of the 274array. (ie., if 'custom_x_ticks' is assigned [0,3,4], then the 0th, 2753rd, and 4th x-ticks will be displayed) 276 277=item 'f_x_tick' 278 279Needs a reference to a function which uses the x-tick labels generated by 280the '@data[0]' as the argument. The result of this function can reformat 281the labels. For instance 282 283 $obj -> set ('f_x_tick' => \&formatter ); 284 285An example for the function formatter: x labels are seconds since an event. 286The referenced function can transform this seconds to hour, minutes and seconds. 287 288=item 'f_y_tick' 289 290The same situation as for 'f_x_tick' but now used for y labels. 291 292=item 'colors' 293 294This option lets you control the colors the chart will use. It takes 295a reference to a hash. The hash should contain keys mapped to references 296to arrays of rgb values. For instance, 297 298 $obj->set('colors' => {'background' => [255,255,255]}); 299 300sets the background color to white (which is the default). Valid keys for 301this hash are 302 303 'background' (background color for the png) 304 'title' (color of the title) 305 'text' (all the text in the chart) 306 'x_label' (color of the x-axis label) 307 'y_label' (color of the first y axis label) 308 'y_label2' (color of the second y axis label) 309 'grid_lines' (color of the grid lines) 310 'x_grid_lines' (color of the x grid lines - for x axis ticks) 311 'y_grid_lines' (color of the y grid lines - for to left y axis ticks) 312 'y2_grid_lines' (color of the y2 grid lines - for right y axis ticks) 313 'dataset0'..'dataset63' (the different datasets) 314 'misc' (everything else, ie. ticks, box around the legend) 315 316NB. For composite charts, there is a limit of 8 datasets per component. 317The colors for 'dataset8' through 'dataset15' become the colors 318for 'dataset0' through 'dataset7' for the second component chart. 319 320=item 'title_font' 321 322This option changes the font of the title. The key has to be a GD font. 323eg. GD::Font->Large 324 325=item 'label_font' 326 327This option changes the font of the labels. The key has to be a GD font. 328 329=item 'legend_font' 330 331This option changes the font of the text in the legend. 332The key has to be a GD font. 333 334=item 'tick_label_font' 335 336This is the font for the tick labels. It also needs 337a GD font object as an argument. 338 339=item 'grey_background' 340 341Puts a nice soft grey background on the actual data plot when 342set to 'true'. Default is 'true'. 343 344=item 'y_axes' 345 346Tells Chart where to place the y-axis. Has no effect on Composite and Pie. 347Valid values are 'left', 'right' and 'both'. Defaults to 'left'. 348 349=item 'x_grid_lines' 350 351Draws grid lines matching up to x ticks if set to 'true'. Default is false. 352 353=item 'y_grid_lines' 354 355Draws grid lines matching up to y ticks if set to 'true'. Default is false. 356 357=item 'grid_lines' 358 359Draws grid lines matching up to x and y ticks. 360 361=item 'spaced_bars' 362 363Leaves space between the groups of bars at each data point when set 364to 'true'. This just makes it easier to read a bar chart. Default 365is 'true'. 366 367=item 'imagemap' 368 369Lets Chart know you're going to ask for information about the placement 370of the data for use in creating an image map from the png. This information 371can be retrieved using the imagemap_dump() method. NB. that the 372imagemap_dump() method cannot be called until after the Chart has been 373generated (ie. using the png() or cgi_png() methods). 374 375=item 'sort' 376 377In a xy-plot, the data will be sorted ascending if set to 'true'. 378(Should be set if the data isn't sorted, especially in Lines, Split 379and LinesPoints) In a Pareto Chart the data will be sorted descending. 380Defaults to 'false'. 381 382=item 'composite_info' 383 384This option is only used for composite charts. It contains the 385information about which types to use for the two component charts, 386and which datasets belong to which component chart. It should be 387a reference to an array of array references, containing information 388like the following 389 390 $obj->set ('composite_info' => [ ['Bars', [1,2]], 391 ['Lines', [3,4] ] ]); 392 393This example would set the two component charts to be a bar chart and 394a line chart. It would use the first two data sets for the bar 395chart (note that the numbering starts at 1, not zero like most of 396the other numbered things in Chart), and the second two data sets 397for the line chart. The default is undef. 398 399NB. Chart::Composite can only do two component charts. 400 401=item 'min_val1', 'min_val2' 402 403Only for composite charts, these options specify the minimum y-value 404for the first and second components respectively. Both default to 405undef. 406 407=item 'max_val1', 'max_val2' 408 409Only for composite charts, these options specify the maximum y-value 410for the first and second components respectively. Both default to 411undef. 412 413=item 'ylabel2' 414 415The label for the right y-axis (the second component chart) on a composite 416chart. Default is undef. 417 418=item 'y_ticks1', 'y_ticks2' 419 420The number of y ticks to use on the first and second y-axis on a composite 421chart. Please note that if you just set the 'y_ticks' option, both axes 422will use that number of y ticks. Both default to undef. 423 424=item 'f_y_ticks1', 'f_y_ticks2' 425 426Only for composite charts, needs a reference to a function 427which has one argument and has to return 428a string which labels the first resp. second y axis. 429Both default to undef. 430 431=item 'same_y_axes' 432 433Forces both component charts in a composite chart to use the same maximum 434and minimum y-values if set to 'true'. This helps to keep the composite 435charts from being too confusing. Default is undef. 436 437=item 'no_cache' 438 439Adds Pragma: no-cache to the http header. Be careful with this one, as 440Netscape 4.5 is unfriendly with POST using this method. 441 442=item 'legend_example_size' 443 444Sets the length of the example line in the legend in pixels. Defaults to 20. 445 446=item 'same_error' 447 448This is a option only for ErrorBars. It tells chart that you want use the same 449error value of a data point if set to 'true'. Look at the documentation 450to see how the module ErrorBars works. Default: 'false'. 451 452=item 'skip_y_ticks' 453 454Does the same for the y-axis at a HorizontalBars chart as 'skip_x_ticks' 455does for other charts. Defaults to 1. 456 457=item 'label_values' 458 459Tells a pie chart what labels to draw beside the pie. Valid values are 460'percent', 'value', 'both' and 'none'. Defaults to 'percent'. 461 462=item 'legend_label_values' 463 464Tells a pie chart what labels to draw in the legend. Valid values are 465'percent', 'value', 'both' and 'none'. Defaults to 'value'. 466 467=item 'start' 468 469Required value for a split chart. Sets the start value of the first interval. 470If the x coordinate of the first data point is zero, you should 'set' to 471zero. Default is 'undef'. 472 473=item 'interval' 474 475Also a required value for a split chart. It sets the interval of one line 476to plot. Defaults 'undef'. 477 478=item 'interval_ticks' 479 480Sets the number of ticks for the x-axis of a Split chart. Defaults to 5. 481 482=item 'scale' 483 484Every y-value of a split chart will be multiplied with that value, but 485the scale won't change. Which means that split allows one to overdraw certain 486rows! Only useful if you want to give prominence to the maximal amplitudes 487of the data. Defaults to 1. 488 489=item 'point' 490 491Indicates to draw points in a direction chart. 'true' or 'false' possible. 492Defaults to 'true'. 493 494=item 'line' 495 496If you turn this option to 'true', then direction will connect the points 497with lines. Defaults to 'false'. 498 499=item 'arrow' 500 501This is also an option for the direction module. If set to 'true', chart 502will draw a arrow from the center to the point. Defaults to 'false'. 503 504=item 'angle_interval' 505 506This option tells direction, how many angle lines should be drawn. The 507default value is 30, which means that a line will be drawn every 50830 degrees. Valid Values are: 0, 5, 10, 15, 20, 30, 45 and 60. If you 509choose 0, direction will draw no line. 510 511=item 'min_circles' 512 513Sets the minimum number of circles when generating a scale for direction. 514Default is 4, minimum is 2. 515 516=item 'max_circles' 517 518Sets the maximum number of circles when generating a scale for direction. 519Default is 100. This limit is used to avoid plotting an unreasonable 520large number of ticks if non-round values are used for the min_val and 521max_val. 522 523=item 'pairs' 524 525Only used for direction how to handle more datasets. 526 If 'pairs' is set to 'true', 527 Chart uses the first dataset as a set of degrees and 528 the second dataset as a set of values. 529 Then, the third set is a set of degrees and the fourth a set of values \dots. \\ 530 If 'pairs' is set to 'false', 531 Chart uses the first dataset as a set of angels 532 and all following datasets as sets of values. 533 Defaults to 'false'. 534 535Sets the maximum number of circles when generating a scale for direction. 536Default is 100. This limit is used to avoid plotting an unreasonable 537large number of ticks if non-round values are used for the min_val and 538max_val. 539 540=back 541 542=head2 GIFgraph.pm-style API 543 544=over 4 545 546=item Sending the image to a file 547 548Invoking the png method causes the graph to be plotted and saved to 549a file. It takes the name of the output file and a reference to the 550data as arguments. For example, 551 552 $obj->png ("foo.png", \@data); 553 554would plot the data in @data, and the save the image to foo.png. 555Of course, this then beggars the question "What should @data look 556like?". Well, just like GIFgraph, @data should contain references 557to arrays of data, with the first array reference pointing to an 558array of x-tick labels. For example, 559 560 @data = ( [ 'foo', 'bar', 'junk' ], 561 [ 30.2, 23.5, 92.1 ] ); 562 563would set up a graph with one dataset, and three data points in that 564set. In general, the @data array should look something like 565 566 @data = ( \@x_tick_labels, \@dataset1, ... , \@dataset_n ); 567 568And no worries, I make my own internal copy of the data, so that it doesn't 569mess with yours. 570 571=item CGI and Chart 572 573Okay, so you're probably thinking, "Do I always have to save these images 574to disk? What if I want to use Chart to create dynamic images for my 575web site?" Well, here's the answer to that. 576 577 $obj->cgi_png ( \@data ); 578 579The cgi_png method will print the chart, along with the appropriate http 580header, to stdout, allowing you to call chart-generating scripts directly 581from your html pages (ie. with a <lt>img src=image.pl<gt> HTML tag). The @data 582array should be set up the same way as for the normal png method. 583 584=back 585 586=head2 Graph.pm-style API 587 588You might ask, "But what if I just want to add a few points to the graph, 589and then display it, without all those references to references?". Well, 590friend, the solution is simple. Borrowing the add_pt idea from Matt 591Kruse's Graph module, you simply make a few calls to the add_pt method, 592like so: 593 594 $obj->add_pt ('foo', 30, 25); 595 $obj->add_pt ('bar', 16, 32); 596 597Or, if you want to be able to add entire datasets, simply use the add_dataset 598method: 599 600 $obj->add_dataset ('foo', 'bar'); 601 $obj->add_dataset (30, 16); 602 $obj->add_dataset (25, 32); 603 604These methods check to make sure that the points and datasets you are 605adding are the same size as the ones already there. So, if you have 606two datasets currently stored, and try to add a data point with three 607different values, it will carp (per the Carp module) an error message. 608Similarly, if you try to add a dataset with 4 data points, 609and all the other datasets have 3 data points, it will carp an error 610message. 611 612Don't forget, when using this API, that I treat the first dataset as 613a series of x-tick labels. So, in the above examples, the graph would 614have two x-ticks, labeled 'foo' and 'bar', each with two data points. 615Pie and ErrorBars handle it different, look at the documentation 616to see how it works. 617 618=over 4 619 620=item Adding a datafile 621 622You can also add a complete datafile to a chart object. Just use the 623add_datafile() method. 624 625 $obj->add_datafile('file', 'set' or 'pt'); 626 627file can be the name of the data file or a filehandle. 628'set' or 'pt is the type of the datafile. 629If the parameter is 'set' then each line in the data file 630has to be a complete data set. The value of the set has to be 631separated by white spaces. For example the file looks like this: 632 633 'foo' 'bar' 634 30 16 635 25 32 636 637If the parameter is 'pt', one line has to include all values 638of one data point separated by white spaces. For example: 639 640 'foo' 30 25 641 'bar' 16 32 642 643 644=item Clearing the data 645 646A simple call to the clear_data method empties any values that may 647have been entered. 648 649 $obj->clear_data (); 650 651=item Getting a copy of the data 652 653If you want a copy of the data that has been added so far, make a call 654to the get_data method like so: 655 656 $dataref = $obj->get_data; 657 658It returns (you guessed it!) a reference to an array of references to 659datasets. So the x-tick labels would be stored as 660 661 @x_labels = @{$dataref->[0]}; 662 663=item Sending the image to a file 664 665If you just want to print this chart to a file, all you have to do 666is pass the name of the file to the png() method. 667 668 $obj->png ("foo.png"); 669 670=item Sending the image to a filehandle 671 672If you want to do something else with the image, you can also pass 673a filehandle (either a typeglob or a FileHandle object) to png, and 674it will print directly to that. 675 676 $obj->png ($filehandle); 677 $obj->png (FILEHANDLE); 678 679 680=item CGI and Chart 681 682Okay, so you're probably thinking (again), "Do I always have to save these 683images to disk? What if I want to use Chart to create dynamic images for 684my web site?" Well, here's the answer to that. 685 686 $obj->cgi_png (); 687 688The cgi_png method will print the chart, along with the appropriate http 689header, to stdout, allowing you to call chart-generating scripts directly 690from your html pages (ie. with a <lt>img src=image.pl<gt> HTML tag). 691 692=back 693 694=item Produce a png image as a scalar 695 696Like scalar_jpeg() the image is produced as a scalar 697so that the programmer-user can do whatever the heck 698s/he wants to with it: 699 700 $obj-scalar_png($dataref) 701 702=back 703 704 705 706=item Produce a jpeg image as a scalar 707 708Like scalar_png() the image is produced as a scalar 709so that the programmer-user can do whatever the heck 710s/he wants to with it: 711 712 $obj-scalar_jpeg($dataref) 713 714=back 715 716=head2 Imagemap Support 717 718Chart can also return the pixel positioning information so that you can 719create image maps from the pngs Chart generates. Simply set the 'imagemap' 720option to 'true' before you generate the png, then call the imagemap_dump() 721method afterwards to retrieve the information. You will be returned a 722data structure almost identical to the @data array described above to pass 723the data into Chart. 724 725 $imagemap_data = $obj->imagemap_dump (); 726 727Instead of single data values, you will be passed references to arrays 728of pixel information. For Bars, HorizontalBars and StackedBars charts, 729the arrays will contain two x-y pairs (specifying the upper left and 730lower right corner of the bar), like so 731 732 ( $x1, $y1, $x2, $y2 ) = @{ $imagemap_data->[$dataset][$datapoint] }; 733 734For Lines, Points, ErrorBars, Split and LinesPoints, the arrays will contain 735a single x-y pair (specifying the center of the point), like so 736 737 ( $x, $y ) = @{ $imagemap_data->[$dataset][$datapoint] }; 738 739A few caveats apply here. First of all, GD treats the upper-left corner 740of the png as the (0,0) point, so positive y values are measured from the 741top of the png, not the bottom. Second, these values will most likely 742contain long decimal values. GD, of course, has to truncate these to 743single pixel values. Since I don't know how GD does it, I can't truncate 744it the same way he does. In a worst-case scenario, this will result in 745an error of one pixel on your imagemap. If this is really an issue, your 746only option is to either experiment with it, or to contact Lincoln Stein 747and ask him. Third, please remember that the 0th dataset will be empty, 748since that's the place in the @data array for the data point labels. 749 750 751=head1 TO DO 752 753=over 4 754 755 756=item * 757 758Add some 3-D graphs. 759Include True Type Fonts 760 761=back 762 763=head1 BUGS 764 765Probably quite a few, since it's been completely rewritten. As usual, 766please mail me with any bugs, patches, suggestions, comments, flames, 767death threats, etc. 768 769=head1 AUTHOR 770 771David Bonner (dbonner@cs.bu.edu) 772 773=head1 MAINTAINER 774 775Chart Group (Chart@fs.wettzell.de) 776 777=head1 COPYRIGHT 778 779Copyright(c) 1997-1998 by David Bonner, 1999 by Peter Clark, 7802001 by the Chart group at BKG-Wettzell. 781All rights reserved. This program is free software; you can 782redistribute it and/or modify it under the same terms as Perl 783itself. 784