It is the user's responsibility to provide appropriate definitions of the PS and PE macros. When the macro package being used does not supply such definitions (for example, old versions of -ms), appropriate definitions can be obtained with -mpic: These will center each picture.
The following options supported by other versions of pic are ignored:
/usr/src/contrib/groff/doc/pic.ms
\centerline{\box\graph}
Actually, since the vbox has a height of zero (it is defined with \vtop) this will produce slightly more vertical space above the picture than below it;
\centerline{\raise 1em\box\graph}
would avoid this.
To make the vbox having a positive height and a depth of zero (as used e.g. by LaTeX's graphics.sty), define the following macro in your document:
\def\gpicbox#1{%
\vbox{\unvbox\csname #1\endcsname\kern 0pt}}
Now you can simply say \gpicbox{graph} instead of \box\graph.
You must use a TeX driver that supports the tpic specials, version 2.
Lines beginning with \ are passed through transparently; a % is added to the end of the line to avoid unwanted spaces. You can safely use this feature to change fonts or to change the value of \baselineskip. Anything else may well produce undesirable results; use at your own risk. Lines beginning with a period are not given any special treatment.
> ..PPSS xx == 1144 ccoommmmaanndd ""..ddss ssttrriinngg xx iiss "" xx "".."" ..PPEE \\**[[ssttrriinngg]]
> ..PPSS ccooppyy tthhrruu %% cciirrccllee aatt (($$11,,$$22)) %% uunnttiill ""EENNDD"" 11 22 33 44 55 66 EENNDD bbooxx ..PPEE
> ..PPSS cciirrccllee aatt ((11,,22)) cciirrccllee aatt ((33,,44)) cciirrccllee aatt ((55,,66)) bbooxx ..PPEE
reset
> ..PPSS xx == 33 yy == 33 [[ xx ::== 55 yy == 55 ]] pprriinntt xx "" "" yy ..PPEE
Arguments of the form
are also allowed to be of the form
In this case anything can contain balanced occurrences of { and }. Strings may contain X or imbalanced occurrences of { and }.
x ^ y
(exponentiation)
sin(x)
cos(x)
atan2(y, x)
log(x)
(base 10)
exp(x)
(base 10, ie
10^_x)
sqrt(x)
int(x)
rand()
(return a random number between 0 and 1)
rand(x)
(return a random number between 1 and
x;
deprecated)
srand(x)
(set the random number seed)
max(e1, e2)
min(e1, e2)
!e
_e_1 &&&& _e_2
_e_1 |||| _e_2
_e_1 ==== _e_2
_e_1 !!== _e_2
_e_1 >>== _e_2
_e_1 >> _e_2
_e_1 <<== _e_2
_e_1 << _e_2
""_s_t_r_1"" ==== ""_s_t_r_2""
""_s_t_r_1"" !!== ""_s_t_r_2""
String comparison expressions must be parenthesised in some contexts to avoid ambiguity.
line 2i
means draw a line 2 inches long in the current direction. The `i' (or `I') character is ignored; to use another measurement unit, set the scale variable to an appropriate value.
The maximum width and height of the picture are taken from the variables maxpswid and maxpsht. Initially these have values 8.5 and 11.
Scientific notation is allowed for numbers. For example
x = 5e-2
Text attributes can be compounded. For example,
"foo" above ljust
is valid.
There is no limit to the depth to which blocks can be examined. For example,
[A: [B: [C: box ]]] with .A.B.C.sw at 1,2
circle at last [].A.B.C
is acceptable.
Arcs now have compass points determined by the circle of which the arc is a part.
Circles, ellipses, and arcs can be dotted or dashed. In TeX mode splines can be dotted or dashed also.
Boxes can have rounded corners. The rad attribute specifies the radius of the quarter-circles at each corner. If no rad or diam attribute is given, a radius of boxrad is used. Initially, boxrad has a value of 0. A box with rounded corners can be dotted or dashed.
The .PS line can have a second argument specifying a maximum height for the picture. If the width of zero is specified the width will be ignored in computing the scaling factor for the picture. Note that GNU pic will always scale a picture by the same amount vertically as well as horizontally. This is different from the DWB 2.0 pic which may scale a picture by a different amount vertically than horizontally if a height is specified.
Each text object has an invisible box associated with it. The compass points of a text object are determined by this box. The implicit motion associated with the object is also determined by this box. The dimensions of this box are taken from the width and height attributes; if the width attribute is not supplied then the width will be taken to be textwid; if the height attribute is not supplied then the height will be taken to be the number of text strings associated with the object times textht. Initially textwid and textht have a value of 0.
In (almost all) places where a quoted text string can be used, an expression of the form
>
ccaann aallssoo bbee uusseedd;;
tthhiiss wwiillll pprroodduuccee tthhee aarrgguummeennttss ffoorrmmaatttteedd aaccccoorrddiinngg ttoo
<>ffoorrmmaatt</ii>>,,
wwhhiicchh sshhoouulldd bbee aa ssttrriinngg aass ddeessccrriibbeedd iinn
<>pprriinnttff((33))</aa>>
aapppprroopprriiaattee ffoorr tthhee nnuummbbeerr ooff aarrgguummeennttss ssuupppplliieedd..
< >
TThhee tthhiicckknneessss ooff tthhee lliinneess uusseedd ttoo ddrraaww oobbjjeeccttss iiss ccoonnttrroolllleedd bbyy tthhee
<>lliinneetthhiicckk</bb>>
vvaarriiaabbllee..
TThhiiss ggiivveess tthhee tthhiicckknneessss ooff lliinneess iinn ppooiinnttss..
AA nneeggaattiivvee vvaalluuee mmeeaannss uussee tthhee ddeeffaauulltt tthhiicckknneessss::
iinn TTeeXX oouuttppuutt mmooddee,, tthhiiss mmeeaannss uussee aa tthhiicckknneessss ooff 88 mmiilllliiiinncchheess;;
iinn TTeeXX oouuttppuutt mmooddee wwiitthh tthhee
<>--cc</bb>>
ooppttiioonn,, tthhiiss mmeeaannss uussee tthhee lliinnee tthhiicckknneessss ssppeecciiffiieedd bbyy
<>..ppss</bb>>
lliinneess;;
iinn ttrrooffff oouuttppuutt mmooddee,, tthhiiss mmeeaannss uussee aa tthhiicckknneessss pprrooppoorrttiioonnaall
ttoo tthhee ppooiinnttssiizzee..
AA zzeerroo vvaalluuee mmeeaannss ddrraaww tthhee tthhiinnnneesstt ppoossssiibbllee lliinnee ssuuppppoorrtteedd bbyy
tthhee oouuttppuutt ddeevviiccee..
IInniittiiaallllyy iitt hhaass aa vvaalluuee ooff --11..
TThheerree iiss aallssoo aa
<>tthhiicckk</bb>>[[<>nneessss</bb>>]]
aattttrriibbuuttee..
FFoorr eexxaammppllee,,
< >
<>cciirrccllee tthhiicckknneessss 11..55</bb>>
< >
wwoouulldd ddrraaww aa cciirrccllee uussiinngg aa lliinnee wwiitthh aa tthhiicckknneessss ooff 11..55 ppooiinnttss..
TThhee tthhiicckknneessss ooff lliinneess iiss nnoott aaffffeecctteedd bbyy tthhee
vvaalluuee ooff tthhee
<>ssccaallee</bb>>
vvaarriiaabbllee,, nnoorr bbyy tthhee wwiiddtthh oorr hheeiigghhtt ggiivveenn iinn tthhee
<>..PPSS</bb>>
lliinnee..
< >
BBooxxeess ((iinncclluuddiinngg bbooxxeess wwiitthh rroouunnddeedd ccoorrnneerrss)),,
cciirrcclleess aanndd eelllliippsseess ccaann bbee ffiilllleedd bbyy ggiivviinngg tthheemm aann aattttrriibbuuttee ooff
<>ffiillll</bb>>[[<>eedd</bb>>]]..
TThhiiss ttaakkeess aann ooppttiioonnaall aarrgguummeenntt ooff aann eexxpprreessssiioonn wwiitthh aa vvaalluuee bbeettwweeeenn
00 aanndd 11;; 00 wwiillll ffiillll iitt wwiitthh wwhhiittee,, 11 wwiitthh bbllaacckk,, vvaalluueess iinn bbeettwweeeenn
wwiitthh aa pprrooppoorrttiioonnaallllyy ggrraayy sshhaaddee..
AA vvaalluuee ggrreeaatteerr tthhaann 11 ccaann aallssoo bbee uusseedd::
tthhiiss mmeeaannss ffiillll wwiitthh tthhee
sshhaaddee ooff ggrraayy tthhaatt iiss ccuurrrreennttllyy bbeeiinngg uusseedd ffoorr tteexxtt aanndd lliinneess..
NNoorrmmaallllyy tthhiiss wwiillll bbee bbllaacckk,, bbuutt oouuttppuutt ddeevviicceess mmaayy pprroovviiddee
aa mmeecchhaanniissmm ffoorr cchhaannggiinngg tthhiiss..
WWiitthhoouutt aann aarrgguummeenntt,, tthheenn tthhee vvaalluuee ooff tthhee vvaarriiaabbllee
<>ffiillllvvaall</bb>>
wwiillll bbee uusseedd..
IInniittiiaallllyy tthhiiss hhaass aa vvaalluuee ooff 00..55..
TThhee iinnvviissiibbllee aattttrriibbuuttee ddooeess nnoott aaffffeecctt tthhee ffiilllliinngg ooff oobbjjeeccttss..
AAnnyy tteexxtt aassssoocciiaatteedd wwiitthh aa ffiilllleedd oobbjjeecctt wwiillll bbee aaddddeedd aafftteerr tthhee
oobbjjeecctt hhaass bbeeeenn ffiilllleedd,, ssoo tthhaatt tthhee tteexxtt wwiillll nnoott bbee oobbssccuurreedd
bbyy tthhee ffiilllliinngg..
< >
TThhrreeee aaddddiittiioonnaall mmooddiiffiieerrss aarree aavvaaiillaabbllee ttoo ssppeecciiffyy ccoolloorreedd oobbjjeeccttss::
<>oouuttlliinnee</bb>>[[<>dd</bb>>]]
sseettss tthhee ccoolloorr ooff tthhee oouuttlliinnee,,
<>sshhaaddeedd</bb>>
tthhee ffiillll ccoolloorr,, aanndd
<>ccoolloo[uu]rr[eedd]
sets both.
All three keywords expect a suffix specifying the color, for example
circle shaded "green" outline "black"
Currently, color support isn't available in TeX mode.
Predefined color names for
groff
are in the device macro files, for example
ps.tmac;
additional colors can be defined with the
.defcolor
request (see the manual page of
troff(1)
for more details).
To change the name of the vbox in TeX mode, set the pseudo-variable
figname
(which is actually a specially parsed command) within a picture.
Example:
.PS
The picture is then available in the box
\foobar.
pic
assumes that at the beginning of a picture both glyph and fill color are
set to the default value.
Arrow heads will be drawn as solid triangles if the variable
arrowhead
is non-zero and either TeX mode is enabled or the
-n
option has not been given.
Initially
arrowhead
has a value of 1.
Note that solid arrow heads are always filled with the current outline
color.
The troff output of
pic
is device-independent.
The
-T
option is therefore redundant.
All numbers are taken to be in inches; numbers are never interpreted
to be in troff machine units.
Objects can have an
aligned
attribute.
This will only work if the postprocessor is
grops.
Any text associated with an object having the
aligned
attribute will be rotated about the center of the object
so that it is aligned in the direction from the start point
to the end point of the object.
Note that this attribute will have no effect for objects whose start and
end points are coincident.
In places where
nth
is allowed
`expr'th
is also allowed.
Note that
'th
is a single token: no space is allowed between the
'
and the
th.
For example,
>
ffoorr ii == 11 ttoo 44 ddoo {{
lliinnee ffrroomm ``ii''tthh bbooxx..nnww ttoo ``ii++11''tthh bbooxx..ssee
}}
It is necessary to feed this file into
groff
without adding any page information, so you must check which
.PS
and
.PE
requests are actually called.
For example, the mm macro package adds a page number, which is very
annoying.
At the moment, calling standard
groff
without any macro package works.
Alternatively, you can define your own requests, e.g. to do nothing:
groff
itself does not provide direct conversion into other graphics file
formats.
But there are lots of possibilities if you first transform your picture
into PostScript format using the
groff
option
-Tps.
Since this
ps-file
lacks BoundingBox information it is not very useful by itself, but it
may be fed into other conversion programs, usually named
ps2other
or
pstoother
or the like.
Moreover, the PostScript interpreter
ghostscript
has built-in graphics conversion devices that are called with the option
gs -sDEVICE=
Call
gs --help
for a list of the available devices.
As the Encapsulated PostScript File Format
EPS
is getting more and more important, and the conversion wasn't regarded
trivial in the past you might be interested to know that there is a
conversion tool named
ps2eps
which does the right job.
It is much better than the tool
ps2epsi
packaged with
gs.
For bitmapped graphic formats, you should use
pstopnm;
the resulting (intermediate)
PNM
file can be then converted to virtually any graphics format using the tools
of the
netpbm
package .
figname = foobar;
...
.PE
CONVERSION
To obtain a stand-alone picture from a
pic
file, enclose your
pic
code with
.PS
and
.PE
requests;
roff
configuration commands may be added at the beginning of the file, but no
roff
text.
..ddee PPSS
....
..ddee PPEE
....
FILES
SEE ALSO
troff(1)
groff_out(5)
tex(1)
gs(1)
ps2eps(1)
pstopnm(1)
ps2epsi(1)
pnm(5)
Tpic: Pic for TeX
Brian W. Kernighan,
PIC -- A Graphics Language for Typesetting (User Manual).
AT&T Bell Laboratories, Computing Science Technical Report No. 116
ps2eps
is available from CTAN mirrors, e.g.
W. Richard Stevens - Turning PIC Into HTML
W. Richard Stevens - Examples of picMacros
The interpretation of
fillval
is incompatible with the pic in 10th edition Unix,
which interprets 0 as black and 1 as white.
PostScript is a registered trademark of Adobe Systems Incorporation.
BUGS
Input characters that are invalid for
groff
(i.e., those with
ASCII
code 0, or 013 octal, or between 015 and 037 octal, or between 0200 and 0237
octal) are rejected even in TeX mode.