PREREX(5)																 PREREX(5)

NAME

       prerex_format -- a format for prerequisite-chart descriptions

DESCRIPTION

       This  manual  describes	the  format of prerequisite-chart descriptions that can be processed by [pdf]latex (normally using a suitable pre-
       rex.sty(7) style file) and edited using the prerex(1) interactive editor (or by any conventional text editor).

TERMINOLOGY

       A prerequisite chart consists of a number of course boxes, linked by arrows.  Courses are either half or  full,	and  may  be  required	or
       optional  (or neither).	Each course box can contain a course code (upper left corner), a course title (lower half), and timetable informa-
       tion (upper right corner).  An arrow can be either a prerequisite (solid), a corequisite (dotted), or recommended (dashed).  When a conven-
       tional arrow would be inappropriate, a mini course just above a target box can be used.

STRUCTURE

       The file should contain exactly one instance of a LaTeX environment

       egin{chart} instruction ... end{chart}

       with  at most one instruction per line.	Note that a program such as prerex(1) analyzes prerex-format files without using TeX; for example,
       macro definitions will be ignored and macro calls will not be expanded.

       Instructions may be preceded by white space.  Lines that start with % are treated as comments and ignored.  The order  of  instructions	is
       not  significant  except  that  the instruction for the source and target box o an arrow should precede the instruction for the arrow.  The
       instruction formats are described in the following sections.

COURSE BOXES

       The instructions producing course boxes have the following forms:

       halfcourse x,y:{code}{title}{timetable}

       fullcourse x,y:{code}{title}{timetable}

       
eqhalfcourse x,y:{code}{title}{timetable}

       
eqfullcourse x,y:{code}{title}{timetable}

       opthalfcourse x,y:{code}{title}{timetable}

       optfullcourse x,y:{code}{title}{timetable}

       where x,y are the coordinates of the centerpoint of the box, relative to the origin of the coordinate system at the  lower-left	corner	of
       the diagram.  The code, title, and timetable arguments are arbitrary (well-bracketed) text, possibly with LaTeX markup.

       The following are similar but take an additional argument to specify the (non-default) background color of the course box:

	      halfcoursec x,y:{code}{title}{timetable}{color}

	      fullcoursec x,y:{code}{title}{timetable}{color}

	      
eqhalfcoursec x,y:{code}{title}{timetable}{color}

	      
eqfullcoursec x,y:{code}{title}{timetable}{color}

	      opthalfcoursec x,y:{code}{title}{timetable}{color}

	      optfullcoursec x,y:{code}{title}{timetable}{color}

MINI COURSE BOXES AND TEXT

       A mini course is produced by an instruction of the form

       mini x,y:{code}

       A text line is inserted into the chart by an instruction of the form

       	ext x,y:{line-of-text}

       The maximum allowed length of a course-code may be smaller that the maximum allowed for a line of text.

ARROWS

       Arrows between course boxes (or from a mini to a course box) are produced by instructions of the form

       prereq x0,y0,x1,y1:

       coreq x0,y0,x1,y1:

       
ecomm x0,y0,x1,y1:

       These produce, respectively, solid, dotted, and dashed arrows from the course box (or mini) centered at coordinates x0,y0 to the course box
       centered at coordinates x1,y1.

       In some implementations, certain arrows by default have a non-zero curvature.  It is possible to override the default curvature for a  par-
       ticular arrow by using the instructions

       prereqc x0,y0,x1,y1;c:

       coreqc x0,y0,x1,y1;c:

       
ecommc x0,y0,x1,y1;c:

       where  c  is  an integer in the range 0-100 specifying the desired curvature; for example, c=0 will produce a straight arrow. To change the
       default curvature, the user program may redefine the DefaultCurvature command.

COORDINATE GRID

       The following instruction produces a coordinate grid, which is useful for editing a diagram:

       grid

       This is normally placed before all the other instructions so that grid lines are in the background, covered by  course  boxes,  minis,  and
       arrows.

WEB LINKS

       Course  boxes  may  be linked to web addresses.	The URL for course boxes may be set by the user by redefining the CourseURL command; when
       called for a course box, it is supplied with three arguments, the x and y coordinates of the box, mini, or textline, and the code  argument
       of the course box. For example,

       
enewcommand{CourseURL}[3]{http://www.cs.queensu.ca/undergraduate/courses/#3.html}

       is  appropriate for courses at the School of Computing, Queen's University.  The first two arguments can be used to display the coordinates
       of a box, mini, or textline in some PDF viewers while the mouse hovers over it when the source file is being edited.

AUTHOR

       R. D. Tennent (rdt@cs.queensu.ca)

SEE ALSO

       prerex(1), prerex.sty(7).

prerex_format							    2012-03-21								 PREREX(5)