chap1.txt

  
  1 The IntPic package
  
  
  1.1 Overview and Introduction
  
  The  IntPic  package  has as its main goal producing Tikz code for arrays of
  integers  to  be included in a LaTeX file, which can then be processed. Some
  of the integers are emphasized, by using different colors for the cells.
  
  IntPic  grew  up  from  my  will  to  have  a pictorial view of some sets of
  integers.  I  wanted,  in  particular,  get  a pictorial view of the results
  produced by the NumericalSgps package [DGSM15]. Effort has then been made to
  serve  a  slightly  more general purpose. For instance, if the user wants to
  have  a pictorial idea of how many primes there are between 800 and 1000, or
  show  it  to  his  students  and, perhaps, which among these primes are twin
  primes, he will probably be happy by producing a picture like the following
  
  It has clearly too much information, given through the different colors. The
  twin  primes  in the given range are in red-blue, while the remaining primes
  in the same range are in red.
  
  This  package contains relatively few lines of code. The heavier part is the
  documentation, where many examples are presented.
  
  The  design  of  this  greatly benefits from my long experience on producing
  visualization  tools  for  GAP  objects.  The  package  sgpviz [DM08] is the
  visible  part.  More recently, I got involved in a more general project, the
  Viz  package [DENMP12]. The experience gained there, especially through long
  and fruitful discussions with J. Mitchell, influenced me a lot. This package
  will  probably  be  part  of that more general project. For the moment it is
  independent,  but its use in conjunction with the Viz package is recommended
  since in this case an immediate visualization is provided.
  
  The  package  produces  tikz code that the user may then use at his wish. In
  particular,  he  can  use it in publications. But prior to obtaining results
  that  lead  to  a  publication, the user may benefit of viewing thousands of
  images.  There  is  a  (almost platform independent) function in Viz that is
  intended  to make this task easy. It benefits from the GAP stuff on creating
  a  temporary  directory  where  the computations occur. The cleaning task is
  also  left  to GAP, which leaves the user free of the need of collecting the
  garbage.  In  order  to  produce  the drawings, LaTeX, as well as some LaTeX
  packages,  in particular tikz and pgf, must be installed and working. I will
  assume that this is the case. All the images in [DFGSL14] have been produced
  by using the IntPic package.
  
  This  package consists basically of a function with many options associated.
  The  purpose  of  the  manual  is to illustrate the use of the options. Many
  examples  are  presented.  A  file,  named examples.g contains the GAP code,
  including  the  one  to  save  the tikz code, to produce the examples in the
  manual.
  
  
  1.2 Installing IntPic
  
  In this section we give a brief description of how to start using IntPic. If
  you have any problems getting IntPic working, then you could try emailing me
  at mailto:[email protected].
  
  It is assumed that you have a working copy of GAP with version number 4.5 or
  higher.  The  most  up-to-date  version  of  GAP  and instructions on how to
  install    it    can    be   obtained   from   the   main   GAP   web   page
  http://www.gap-system.org.
  
  If  the  IntPic  package was obtained as a part of the GAP distribution from
  the  Download  section  of  the GAP website, you may proceed to Section 1.3.
  Alternatively, the IntPic package may be installed using a separate archive,
  for example, for an update or an installation in a non-default location (see
  'Reference: GAP Root Directories').
  
  Below we describe the installation procedure for the .tar.gz archive format,
  which   can  be  obtained  from  http://cmup.fc.up.pt/cmup/mdelgado/intpic/.
  Installation  using  other  archive  formats  or  non  UNIX-like  systems is
  performed in a similar way.
  
  To  install the IntPic package, unpack the archive file, which should have a
  name of the form  intpic-XXX.tar.gz  for some version number XXX, by typing
  
      gzip -dc intpic-XXX.tar.gz | tar xpv 
  
  It may be unpacked in one of the following locations:
  
      in the pkg directory of your GAP installation;
  
      or  in  a directory named .gap/pkg in your home directory (to be added
        to the GAP root directory unless GAP is started with -r option);
  
      or  in  a  directory  named  pkg  in  another directory of your choice
        (e.g. in the directory mygap in your home directory).
  
  In  the  latter  case  one  must  start GAP with the -l option, e.g. if your
  private  pkg directory is a subdirectory of mygap in your home directory you
  might type:
  
      gap -l ";myhomedir/mygap" 
  
  where myhomedir is the path to your home directory, which may be replaced by
  a  tilde  (the  empty  path before the semicolon is filled in by the default
  path of the GAP home directory).
  
  
  1.3 Loading IntPic
  
  To use the IntPic Package you have to request it explicitly. This is done by
  calling LoadPackage (Reference: LoadPackage):
  
    Example  
    gap> LoadPackage("intpic");
  
  
  The  package  banner,  followed by true, will be shown, if the load has been
  successful.
  
  If  you  want  to  load  the  IntPic  package  by  default,  you can put the
  LoadPackage  command  into  your  gaprc  file  (see  Section 'Reference: The
  gap.ini and gaprc files').