/usr/share/doc/gri/html/Variables.html is in gri-html-doc 2.12.23-9build2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Gri: variables</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"></head>
<body bgcolor="#FFFFFF" text="#000000" link="#0000EE" vlink="#551A8B" alink="FF0000">
<!-- newfile Variables.html "Gri: variables" "Programming Gri" -->
<!-- @node Variables, About Variables, Long Command Lines, Programming -->
<a name="Variables" ></a>
<img src="./resources/top_banner.gif" alt="navigation map" usemap="#navigate_top" border="0">
<table summary="top banner" border="0" cellspacing="0" cellpadding="0">
<tr>
<td width="150" valign="top">
<font size=-1>
<br>
Chapters:
<br>
<a href="Introduction.html">1: Introduction</a><br>
<a href="SimpleExample.html">2: Simple example</a><br>
<a href="InvokingGri.html">3: Invocation</a><br>
<a href="GettingMoreControl.html">4: Finer Control</a><br>
<a href="X-Y.html">5: X-Y Plots</a><br>
<a href="ContourPlots.html">6: Contour Plots</a><br>
<a href="Images.html">7: Image Plots</a><br>
<a href="Examples.html">8: Examples</a><br>
<a href="Commands.html">9: Gri Commands</a><br>
<a href="Programming.html">10: Programming</a><br>
<a href="Environment.html">11: Environment</a><br>
<a href="Emacs.html">12: Emacs Mode</a><br>
<a href="History.html">13: History</a><br>
<a href="Installation.html">14: Installation</a><br>
<a href="Bugs.html">15: Gri Bugs</a><br>
<a href="TestSuite.html">16: Test Suite</a><br>
<a href="GriInThePress.html">17: Gri in Press</a><br>
<a href="Acknowledgments.html">18: Acknowledgments</a><br>
<a href="License.html">19: License</a><br>
<br>
Indices:<br>
<a href="ConceptIndex.html"><i>Concepts</i></a><br>
<a href="CommandIndex.html"><i>Commands</i></a><br>
<a href="BuiltinIndex.html"><i>Variables</i></a><br>
</font>
<td width="500" valign="top">
<map name="navigate_top">
<area alt="index.html#Top" shape="rect" coords="5,2,218,24" href="index.html#Top">
<area alt="Programming.html#Programming" shape="rect" coords="516,2,532,24" href="Programming.html#Programming">
<area alt="Gri: long command lines" shape="rect" coords="557,2,573,24" href="LongCommandLines.html">
<area alt="Gri: synonyms" shape="rect" coords="581,2,599,24" href="Synonyms.html">
</map>
<map name="navigate_bottom">
<area alt="index.html#Top" shape="rect" coords="5,2,218,24" href="index.html#Top">
<area alt="Gri: synonyms" shape="rect" coords="581,2,599,24" href="Synonyms.html">
</map>
<h2>10.4: Variables</h2>
<UL>
<LI><a href="Variables.html#AboutVariables">About Variables</a>: What variables are used for, and how
<LI><a href="Variables.html#UserVariables">User Variables</a>: Defining your own variables
<LI><a href="Variables.html#Built-inVariables">Built-in Variables</a>: Variables pre-defined by Gri
</UL>
<!-- @node About Variables, User Variables, Variables, Variables -->
<a name="AboutVariables" ></a>
<h3>10.4.1: About variables</h3>
Variables store numbers. As it reads your program, Gri
substitutes variable values any place a variable appears where a number
normally would. For example, in the code below `<font color="#82140F"><code>.number.</code></font>' is a
variable storing the value 10, so the two `<font color="#82140F"><code>read</code></font>' statements have
the same effect:
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
.number. = 10
read columns .number. x y
read columns 10 x y
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
Variable names begin and end with a single period (example:
`<font color="#82140F"><code>.num.</code></font>'). (Gri uses this odd notation to distinguish variable
names from ``normal'' words, which is necessary because Gri does not
have a limited list of keywords as other languages do. Thus, the C
programming language is happy to let you use a variable name like
`<font color="#82140F"><code>latitude</code></font>', since it is not a keyword, but Gri is not, since it
might like to use that word itself in a new command.)
<p>
You should not use names beginning and ending with double periods,
because Gri uses names like that to store built-in variables for its own
use (e.g., `<font color="#82140F"><code>..xsize..</code></font>' saves the width of the plot).
<p>
To store a number into a variable, use a command like
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
.time. = 10
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
or
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
.time. = {rpn 10 sin}
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
Storage is automatically set aside when you assign into a nonexistent
variable; no ``declaration'' statements are required as in the C
language.
<p>
The Gri command, `<font color="82140F"><code>new</code></font>' (see <a href="New.html#New">New</a>), allows you to have several
``versions'' of a variable. This is useful for local storage in new
commands, inside `<font color="#82140F"><code>if</code></font>' statements, etc, since it lets you use
temporary variables without worrying about overwriting values outside
the local block of code. The syntax is `<font color="#82140F"><code>new .variable. = value</code></font>'
(where, as usual, `<font color="#82140F"><code>value</code></font>' may be an rpn expression
(see <a href="ReversePolishMath.html#rpnMathematics">rpn Mathematics</a>). Here is an example:
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
`foo bar'
{
new .a. # Get storage
.a. = 10 # Store a local value
show "Locally, .a.=" .a. " (expect 10)"
delete .a. # Delete this local one
}
.a. = 1
show "Global version has .a.=" .a. " (expect 1)"
foo bar
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
To see if a given named variable (or synonym) exists, use the RPN
operator `<font color="82140F"><code>defined</code></font>' (see <a href="ReversePolishMath.html#rpnMathematics">rpn Mathematics</a>).
<p>
<!-- @node User Variables, Built-in Variables, About Variables, Variables -->
<a name="UserVariables" ></a>
<h3>10.4.2: User variables</h3>
You can get Gri to read values for variables from your file. Here's how
to read a number from a header line and then read that many lines of
columnar data:
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
open file.dat
read .num.
read columns .num. x y
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
You can define variables within the Gri program:
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
.num. = 10
read columns .num. x y
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
You can get variables interactively from the user, using the
`<font color="#82140F"><code>query</code></font>' command. (If the user types carriage-return, or if the
command-line flag `<font color="#82140F"><code>-y</code></font>' was specified when invoking Gri, the value
100 will be assigned to `<font color="#82140F"><code>.num.</code></font>').
For example,
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
query .num. "Number of rows to read?" (100)
read columns .num. x y
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
Gri allows you to use a previous value of the variable in the default
string, as in this example:
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
.start. = 8 # default
.stop. = 2 # default
query .start. "Start time? " (.start.)
query .stop. "Stop time? " (.stop.)
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
Variables can be manipulated using reverse polish notation (RPN)
mathematical operations (see <a href="ReversePolishMath.html#rpnMathematics">rpn Mathematics</a>).
<p>
Variables are often useful in `<font color="#82140F"><code>if</code></font>' statements. Here are some
examples:
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
read .num_pts.
if .num_pts.
show "There are some data"
read columns .num_pts. x y
else
show "There are no data"
end if
# ...
read .latitude.
if {rpn .latitude. 10 <}
read .num.
read .num. x y
draw curve
else
show "Skipping data North of 10deg N"
read .num.
skip .num.
end if
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
<!-- @node Built-in Variables, Synonyms, User Variables, Variables -->
<a name="Built-inVariables" ></a>
<h3>10.4.3: Built-in variables</h3>
Built-in variables (see <a href="BuiltinIndex.html#IndexofBuiltins">Index of Builtins</a>) have names which begin and
end with <b>two</b> periods. For example, `<font color="#82140F"><code>..xsize..</code></font>' is the width
of the x-axis in centimetres. You may use these variables as you wish
(example: `<font color="#82140F"><code>..xsize.. = 4</code></font>' is an alternative to
`<font color="#82140F"><code>set x size 4</code></font>'), but you must be aware that these are not ``free''
variables for you to use for arbitrary purposes. You can find out what
the built-in variables are by the command `<font color="#82140F"><code>show variables</code></font>'.
<p>
There are two types of variables
<ul>
<li>
<b>Startup</b> variables, which are created by Gri at startup time.
These variables can be relied upon to exist (barring changes in Gri
itself), unless you `<font color="#82140F"><code>delete</code></font>' them.
<li>
<b>Spontaneous</b> variables (which are created by certain Gri commands,
and only exist if these commands have been executed). For example, the
`<font color="#82140F"><code>regress</code></font>' command defines `<font color="#82140F"><code>..coeff0..</code></font>' (the intercept of the
fitted line), `<font color="#82140F"><code>..coeff1..</code></font>' (the slope of the fitted line),
`<font color="#82140F"><code>..R2..</code></font>' (the correlation coefficient).
</ul>
<p>
To see the values of the built-in variables (along with the user
variables), use `<font color="#82140F"><code>show variables</code></font>'. Here are some useful builtin
variables:
<p>
<ul>
<p>
<li> `<font color="#82140F"><code>..arrowsize..</code></font>'
<!-- latex: \index{@code{..arrowsize..}, size of arrows} -->
Stores either a positive number representing the halfwidth of arrowheads
measured in centimetres, or a negative number giving the negative of the
ratio of arrowhead halfwidth to arrow length (see <a href="Set.html#SetArrowSize">Set Arrow Size</a>).
<p>
<li> `<font color="#82140F"><code>..batch..</code></font>'
<!-- latex: \index{@code{..batch..}, flag used for batch mode} -->
Flag used for batch mode.
<p>
<li> `<font color="#82140F"><code>..debug..</code></font>'
<!-- latex: \index{@code{..debug..}, flag used for debugging} -->
Equal to 1 if the `<font color="#82140F"><code>-debug</code></font>' command-line flag was set. Flag used
for debugging (see <a href="InvokingGri.html#InvokingGri">Invoking Gri</a>). The `<font color="82140F"><code>..debug..</code></font>'
built-in variable is useful in isolating code to use only in test runs.
For example, you might use
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
if ..debug..
show "Following are the column data"
show columns
end if
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
When you run the program with command-line `<font color="#82140F"><code>gri -debug file.gri</code></font>'
the code in the `<font color="#82140F"><code>if</code></font>' block will print out the columnar data, but
when you run it with `<font color="#82140F"><code>gri file.gri</code></font>' these lines are not printed.
<p>
<li> `<font color="#82140F"><code>..eof..</code></font>'
<!-- latex: \index{@code{..eof..}, flag indicating end-of-file} -->
Flag indicating whether an end-of-file was encountered on the last
`<font color="#82140F"><code>read columns</code></font>'.
<p>
<li> `<font color="#82140F"><code>..words_in_dataline..</code></font>'
<!-- latex: \index{@code{..words_in_dataline..}} -->
Number of words on last dataline. This is useful in constructs like
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
open tmp.dat
.num. = 0
while 1
read .a. .b.
if !..words_in_dataline..
show "Got empty line or EOF, so break loop"
break
end if
show "a=" .a. "b=" .b.
show "; words in line=" ..words_in_dataline..
.num. += 1
end while
show "Got " .num. "data lines."
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
<li> `<font color="#82140F"><code>..fontsize..</code></font>'
<!-- latex: \index{@code{..fontsize..}, size of letters} -->
Size of letters, measured in points; there are 72.27 points in an inch
and 28.45 points in a centimetre. The mathematical operators
`<font color="#82140F"><code>pttocm</code></font>' and `<font color="#82140F"><code>cmtopt</code></font>', which do conversion between points and
centimetres, are often useful in labelling data curves
(see <a href="ReversePolishMath.html#rpnMathematics">rpn Mathematics</a>).
<p>
<li> `<font color="#82140F"><code>..graylevel..</code></font>'
<!-- latex: \index{@code{..graylevel..}, graylevel (0=black)} -->
Graylevel to use in drawing lines, text, etc. Black ink is 0; white
paper is 1. <b>See also</b> `<font color="#82140F"><code>..red..</code></font>' etc.
<p>
<li> `<font color="#82140F"><code>..image_height..</code></font>'
<!-- latex: \index{@code{..image_height..}, height of image} -->
Height of image, or 0 if no image defined yet.
<p>
<li> `<font color="#82140F"><code>..image_width..</code></font>'
<!-- latex: \index{@code{..image_width..}, width of image} -->
Width of image, or 0 if no image defined yet.
<p>
<li> `<font color="#82140F"><code>..length_dash..</code></font>'
<!-- latex: \index{@code{..length_dash..}, length/cm of dashes} -->
Length in cm of dashes in dashed lines.
<p>
<li> `<font color="#82140F"><code>..length_blank..</code></font>'
<!-- latex: \index{@code{..length_blank..}, length/cm of blanks} -->
Length in cm of blanks in dashed lines.
<p>
<li> `<font color="#82140F"><code>..linewidth..</code></font>'
<!-- latex: \index{@code{..linewidth..}, width of lines} -->
Width of lines for data curves (see <a href="Set.html#SetLineWidth">Set Line Width</a>).
<p>
<li> `<font color="#82140F"><code>..linewidthaxis..</code></font>'
<!-- latex: \index{@code{..linewidthaxis..}, width of lines on axis} -->
Width of lines on axes (see <a href="Set.html#SetLineWidth">Set Line Width</a>).
<p>
<li> `<font color="#82140F"><code>..linewidthsymbol..</code></font>'
<!-- latex: \index{@code{..linewidthsymbol..}, width of lines in symbols} -->
Width of lines in symbols (see <a href="Set.html#SetLineWidth">Set Line Width</a>).
<p>
<li> `<font color="#82140F"><code>..missingvalue..</code></font>'
<!-- latex: \index{@code{..missingvalue..}, missing value code} -->
Missing value code, also stored in the synonym `<font color="#82140F"><code>\.missingvalue.</code></font>';
(see <a href="Set.html#SetMissingValue">Set Missing Value</a>).
<p>
<li> `<font color="#82140F"><code>..num_col_data..</code></font>'
<!-- latex: \index{@code{..num_col_data..}, number column data} -->
Number of column data that exist. You might want to use this after
`<font color="#82140F"><code>read columns</code></font>' to see if a data file actually had any data in it,
or use it in accessing individual elements of columns
(see <a href="ReversePolishMath.html#rpnMathematics">rpn Mathematics</a>).
<p>
<li> `<font color="#82140F"><code>..publication..</code></font>'
<!-- latex: \index{@code{..publication..}, flag for final copy of plot} -->
Flag for final copy of plot. The command-line option `<font color="#82140F"><code>-p</code></font>' sets the
value of `<font color="#82140F"><code>..publication..</code></font>' to 1. A typical, and highly
recommended, code fragment is
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
if !..publication..
draw time stamp
end if
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
<li> `<font color="#82140F"><code>..red..</code></font>', `<font color="#82140F"><code>..green..</code></font>', `<font color="#82140F"><code>..blue..</code></font>'
<!-- latex: \index{@code{..blue..}} -->
Description of present color. The values are between 0 and 1, with
(0,0,0) being black and (1,1,1) being white. If color is gray, all
these will be equal. You may assign to these, but it will <b>not</b>
change the color.
<p>
<li> `<font color="#82140F"><code>..symbolsize..</code></font>'
<!-- latex: \index{@code{..symbolsize..}, size of symbols} -->
Size of symbols in centimetres.
<p>
<li> `<font color="#82140F"><code>..superuser..</code></font>'
<!-- latex: \index{@code{..superuser..}, was -superuser flag set?} -->
Equal to 0 if the flag was not set, or equal to the flag if it was.
<p>
<li> `<font color="#82140F"><code>..tic_direction..</code></font>'
<!-- latex: \index{@code{..tic_direction..}, direction of axis tics} -->
Direction of axis tics, 1 for inside or 0 for outside.
<p>
<li> `<font color="#82140F"><code>..tic_size..</code></font>'
<!-- latex: \index{@code{..tic_size..}, size/cm of axis tics} -->
Size of axis tics in centimetres.
<p>
<li> `<font color="#82140F"><code>..trace..</code></font>'
<!-- latex: \index{@code{..trace..}, for tracing program execution} -->
Equal to 1 if the `<font color="#82140F"><code>-trace</code></font>' command-line flag was set. Used for
tracing program execution.
<p>
<li> `<font color="#82140F"><code>..xinc..</code></font>'
<!-- latex: \index{@code{..xinc..}, x increment on axes} -->
x increment on axes.
<p>
<li> `<font color="#82140F"><code>..xleft..</code></font>'
<!-- latex: \index{@code{..xleft..}, x value at left of plot} -->
x value at left of plot.
<p>
<li> `<font color="#82140F"><code>..xmargin..</code></font>'
<!-- latex: \index{@code{..xmargin..}, left margin} -->
Left margin, in centimetres.
<p>
<li> `<font color="#82140F"><code>..xright..</code></font>'
<!-- latex: \index{@code{..xright..}, x value at right of plot} -->
x value at right of plot.
<p>
<li> `<font color="#82140F"><code>..xsize..</code></font>'
<!-- latex: \index{@code{..xsize..}, x-axis length} -->
x-axis length in centimetres.
<p>
<li> `<font color="#82140F"><code>..ybottom..</code></font>'
<!-- latex: \index{@code{..ybottom..}, y value at bottom of plot} -->
y value at bottom of plot.
<p>
<li> `<font color="#82140F"><code>..yinc..</code></font>'
<!-- latex: \index{@code{..yinc..}, y increment on axes} -->
y increment on axes.
<p>
<li> `<font color="#82140F"><code>..ymargin..</code></font>'
<!-- latex: \index{@code{..ymargin..}, bottom margin} -->
Bottom margin in centimetres.
<p>
<li> `<font color="#82140F"><code>..ysize..</code></font>'
<!-- latex: \index{@code{..ysize..}, y-axis length} -->
y-axis length in centimetres.
<p>
<li> `<font color="#82140F"><code>..ytop..</code></font>'
<!-- latex: \index{@code{..ytop..}, y value at top of plot} -->
y value at top of plot
<p>
<li> `<font color="#82140F"><code>..exit_status..</code></font>'
<!-- latex: \index{@code{..exit_status..}, exit status from @code{system} call} -->
The exit status from the most recent `<font color="#82140F"><code>system</code></font>' call (or 0 if no
system calls have been done yet).
</ul>
<p>
You may use any of these built-in variables anywhere. For example,
here's how to stack 3 graphs vertically on the page:
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
.offset. = {rpn ..ysize.. 3 + }
open file1
read columns x y
close
draw axes
draw curve
<p>
..ymargin.. += .offset.
open file2
read columns x y
draw axes
draw curve
close
<p>
..ymargin.. += .offset.
open file3
read columns x y
draw axes
draw curve
close
</font></PRE>
</TD>
</TR>
</TABLE>
<p>
The first line needs a bit of explanation. It is a reverse-polish
expression. The format is `<font color="#82140F"><code>{</code></font>' followed by `<font color="#82140F"><code>rpn</code></font>' followed by
an expression followed by `<font color="#82140F"><code>}</code></font>'. Within the expression, spaces must
separate operands. This makes `<font color="#82140F"><code>.offset.</code></font>' equal to the height of
y-axis plus 3 cm, so plots are separated by 3 cm. To learn more about
`<font color="82140F"><code>{rpn ... }</code></font>' (see <a href="ReversePolishMath.html#rpnMathematics">rpn Mathematics</a>).
<p>
Another possibly unfamiliar thing is the code `<font color="#82140F"><code>+=</code></font>'. It means take
the thing on the left hand side, and add to it the thing on the right
hand side. (In this case, it is used to increase the y margin by the
value of `<font color="#82140F"><code>.offset.</code></font>'.)
<p>
</table>
<img src="./resources/bottom_banner.gif" alt="navigation map" usemap="#navigate_bottom" border="0">
</body>
</html>
|