Man Pages

pic(1) - phpMan pic(1) - phpMan

Command: man perldoc info search(apropos)  

PIC(1)                                                                  PIC(1)

       pic - compile pictures for troff or TeX

       pic [ -nvCSU ] [ filename ... ]
       pic -t [ -cvzCSU ] [ filename ... ]

       This  manual page describes the GNU version of pic, which is part of the groff document formatting system.  pic
       compiles descriptions of pictures embedded within troff or TeX input files into commands that are understood by
       TeX  or  troff.   Each  picture  starts with a line beginning with .PS and ends with a line beginning with .PE.
       Anything outside of .PS and .PE is passed through without change.

       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.

       Options that do not take arguments may be grouped behind a single -.  The special option -- can be used to mark
       the end of the options.  A filename of - refers to the standard input.

       -C     Recognize .PS and .PE even when followed by a character other than space or newline.

       -S     Safer  mode;  do  not  execute  sh  commands.  This can be useful when operating on untrustworthy input.
              (enabled by default)

       -U     Unsafe mode; revert the default option -S.

       -n     Don't use the groff extensions to the troff drawing commands.  You should use this if you  are  using  a
              postprocessor that doesn't support these extensions.  The extensions are described in groff_out(5).  The
              -n option also causes pic not to use zero-length lines to draw dots in troff mode.

       -t     TeX mode.

       -c     Be more compatible with tpic.  Implies -t.  Lines beginning with \ are not passed through transparently.
              Lines  beginning with .  are passed through with the initial .  changed to \.  A line beginning with .ps
              is given special treatment: it takes an optional integer argument specifying  the  line  thickness  (pen
              size)  in  milliinches; a missing argument restores the previous line thickness; the default line thick-
              ness is 8 milliinches.  The line thickness thus specified takes effect only  when  a  non-negative  line
              thickness has not been specified by use of the thickness attribute or by setting the linethick variable.

       -v     Print the version number.

       -z     In TeX mode draw dots using zero-length lines.

       The following options supported by other versions of pic are ignored:

       -D     Draw all lines using the \D escape sequence.  pic always does this.

       -T dev Generate output for the troff device dev.  This is unnecessary because the troff output generated by pic
              is device-independent.

       This  section  describes  only  the differences between GNU pic and the original version of pic.  Many of these
       differences also apply to newer versions of Unix pic.  A complete documentation is available in the file


   TeX mode
       TeX mode is enabled by the -t option.  In TeX mode, pic will define a vbox called \graph for each picture.  You
       must yourself print that vbox using, for example, the command


       Actually,  since the vbox has a height of zero this will produce slightly more vertical space above the picture
       than below it;

              \centerline{\raise 1em\box\graph}

       would avoid this.

       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.

       for variable = expr1 to expr2 [by [*]expr3] do X body X
              Set  variable  to expr1.  While the value of variable is less than or equal to expr2, do body and incre-
              ment variable by expr3; if by is not given, increment variable by 1.  If expr3 is  prefixed  by  *  then
              variable will instead be multiplied by expr3.  X can be any character not occurring in body.

       if expr then X if-true X [else Y if-false Y]
              Evaluate  expr;  if  it  is non-zero then do if-true, otherwise do if-false.  X can be any character not
              occurring in if-true.  Y can be any character not occurring in if-false.

       print arg...
              Concatenate the arguments and print as a line on stderr.  Each arg must be an expression, a position, or
              text.  This is useful for debugging.

       command arg...
              Concatenate  the arguments and pass them through as a line to troff or TeX.  Each arg must be an expres-
              sion, a position, or text.  This has a similar effect to a line beginning with . or \,  but  allows  the
              values of variables to be passed through.

       sh X command X
              Pass command to a shell.  X can be any character not occurring in command.

       copy "filename"
              Include filename at this point in the file.

       copy ["filename"] thru X body X [until "word"]
       copy ["filename"] thru macro [until "word"]
              This  construct  does body once for each line of filename; the line is split into blank-delimited words,
              and occurrences of $i in body, for i between 1 and 9, are replaced by the i-th word  of  the  line.   If
              filename  is  not given, lines are taken from the current input up to .PE.  If an until clause is speci-
              fied, lines will be read only until a line the first word of which is word; that line will then be  dis-
              carded.  X can be any character not occurring in body.  For example,

                     copy thru % circle at ($1,$2) % until "END"
                     1 2
                     3 4
                     5 6

              is equivalent to

                     circle at (1,2)
                     circle at (3,4)
                     circle at (5,6)

              The  commands to be performed for each line can also be taken from a macro defined earlier by giving the
              name of the macro as the argument to thru.

       reset variable1[,] variable2 ...
              Reset pre-defined variables variable1, variable2 ... to their  default  values.   If  no  arguments  are
              given,  reset  all  pre-defined variables to their default values.  Note that assigning a value to scale
              also causes all pre-defined variables that control dimensions to be reset to their default values  times
              the new value of scale.

       plot expr ["text"]
              This is a text object which is constructed by using text as a format string for sprintf with an argument
              of expr.  If text is omitted a format string of "%g" is used.  Attributes can be specified in  the  same
              way  as  for  a  normal text object.  Be very careful that you specify an appropriate format string; pic
              does only very limited checking of the string.  This is deprecated in favour of sprintf.

       variable := expr
              This is similar to = except variable must already be defined, and expr  will  be  assigned  to  variable
              without  creating  a  variable  local to the current block.  (By contrast, = defines the variable in the
              current block if it is not already defined there, and then changes the value in the current block only.)
              For example, the following:

                     x = 3
                     y = 3
                       x := 5
                       y = 5
                     print x " " y

              prints 5 3.

       Arguments of the form

              X anything X

       are also allowed to be of the form

              { anything }

       In  this case anything can contain balanced occurrences of { and }.  Strings may contain X or imbalanced occur-
       rences of { and }.

       The syntax for expressions has been significantly extended:

       x ^ y (exponentiation)
       atan2(y, x)
       log(x) (base 10)
       exp(x) (base 10, ie 10^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)
       e1 && e2
       e1 || e2
       e1 == e2
       e1 != e2
       e1 >= e2
       e1 > e2
       e1 <= e2
       e1 < e2
       "str1" == "str2"
       "str1" != "str2"

       String comparison expressions must be parenthesised in some contexts to avoid ambiguity.

   Other Changes
       A bare expression, expr, is acceptable as an attribute; it is equivalent to dir expr, where dir is the  current
       direction.  For example

              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 legal.

       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 and arcs can be dotted or dashed.  In TeX mode splines can be dotted or dashed.

       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

       In (almost all) places where a quoted text string can be used, an expression of the form

              sprintf("format", arg,...)

       can also be used; this will produce the arguments formatted according to format, which should be  a  string  as
       described in printf(3) appropriate for the number of arguments supplied.

       The thickness of the lines used to draw objects is controlled by the linethick variable.  This gives the thick-
       ness of lines in points.  A negative value means use the default thickness: in TeX output mode, this means  use
       a  thickness  of 8 milliinches; in TeX output mode with the -c option, this means use the line thickness speci-
       fied by .ps lines; in troff output mode, this means use a thickness proportional  to  the  pointsize.   A  zero
       value  means  draw  the thinnest possible line supported by the output device.  Initially it has a value of -1.
       There is also a thick[ness] attribute.  For example,

              circle thickness 1.5

       would draw a circle using a line with a thickness of 1.5 points.  The thickness of lines is not affected by the
       value of the scale variable, nor by the width or height given in the .PS line.

       Boxes (including boxes with rounded corners), circles and ellipses can be filled by giving them an attribute of
       fill[ed].  This takes an optional argument of an expression with a value between 0 and 1; 0 will fill  it  with
       white,  1  with  black, values in between with a proportionally gray shade.  A value greater than 1 can also be
       used: this means fill with the shade of gray that is currently being used for text and  lines.   Normally  this
       will  be  black,  but  output devices may provide a mechanism for changing this.  Without an argument, then the
       value of the variable fillval will be used.  Initially this has a value of 0.5.  The invisible  attribute  does
       not affect the filling of objects.  Any text associated with a filled object will be added after the object has
       been filled, so that the text will not be obscured by the filling.

       Three additional modifiers are available to specify colored objects: outline[d] sets the color of the  outline,
       shaded  the  fill  color, and colo[u]r[ed] 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).

       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,

              for i = 1 to 4 do {
                 line from 'i'th box.nw to 'i+1'th

       To obtain a stand-alone picture from a pic file, enclose your pic code with .PS and .PE requests; roff configu-
       ration commands may be added at the beginning of the file, but no roff text.

       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:

              .de PS
              .de PE

       groff itself does not provide direct conversion into other graphics file formats.  But there are lots of possi-
       bilities if you first transform your picture into PostScript(R) 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
       (gs) has built-in graphics conversion devices that are called with the option

              gs -sDEVICE=<devname>

              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 con-
       verted to virtually any graphics format using the tools of the netpbm package .

       /usr/share/groff/   Example definitions of the PS and PE macros.

       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 <>; (revised May, 1991).

       ps2eps is available from CTAN mirrors, e.g.

       W. Richard Stevens - Turning PIC Into HTML

       W. Richard Stevens - Examples of picMacros

       Input  characters  that are invalid for groff (ie 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.

       The interpretation of fillval is incompatible with the pic in 10th edition Unix, which interprets  0  as  black
       and 1 as white.

       PostScript(R) is a registered trademark of Adobe Systems Incorporation.

Groff Version         20 September 2002                        PIC(1)