SWEEP2_VORONOI_EPS
Plot the SWEEP2 Voronoi Diagram

SWEEP2_VORONOI_EPS is a FORTRAN90 program which plots the Voronoi diagram output from sweep2.

Usage:

sweep2_voronoi_eps voronoi_data graph

voronoi_data: is a text file containing a description of the Voronoi diagram, output by sweep2. Each line describes either a site, a vertex, an abstract line, or a Voronoi edge. Indices are counted starting at 0.
graph: is an Encapsulated PostScript file containing an image of the Voronoi diagram.

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

SWEEP2_VORONOI_EPS is available in a FORTRAN90 version.

Related Data and Programs:

SWEEP2, a C program which performs the Delaunay triangulation of a set of points, by Steve Fortune.

SWEEP2_DELAUNAY_EPS, a FORTRAN90 program which produces an Encapsulated PostScript image of the Delaunay triangulation of a set of points, as processed by the SWEEP2 program.

Reference:

1. Franz Aurenhammer,
   Voronoi diagrams - a study of a fundamental geometric data structure,
   ACM Computing Surveys,
   Volume 23, pages 345-405, September 1991.
2. Steve Fortune,
   A Sweepline Algorithm for Voronoi Diagrams,
   Algorithmica, Volume 2, pages 153-174, 1987.
A copy of the original release of the SWEEP2 code is available through NETLIB at http://www.netlib.org/voronoi/sweep2

Source Code:

• sweep2_voronoi_eps.f90, the source code.
• sweep2_voronoi_eps.sh, commands to compile the source code.

Examples and Tests:

DIAMOND is a simple pointset of 9 points:

• diamond.txt, the file containing the point coordinates.
• diamond_vor.txt, the file containing the Voronoi diagram information.
• diamond_vor.png, a PNG image of the Voronoi diagram.

TEST is a pointset of 100 points:

• test.txt, the file containing the point coordinates.
• test_vor.txt, the file containing the Voronoi diagram information.
• test_vor.png, a PNG image of the Voronoi diagram.

List of Routines:

• MAIN is the main program for SWEEP2_VORONOI_EPS.
• BOX_CLIP_LINE_2D uses a box to clip a line segment in 2D.
• CH_CAP capitalizes a single character.
• CH_EQI is a case insensitive comparison of two characters for equality.
• CH_TO_DIGIT returns the integer value of a base 10 digit.
• EPS_FILE_HEAD writes header information to an encapsulated PostScript file.
• EPS_FILE_TAIL writes trailer information to an encapsulated PostScript file.
• GET_FILENAMES gets the filenames from the command line or the user.
• GET_UNIT returns a free FORTRAN unit number.
• I4_SWAP swaps two I4's.
• POINT_INSIDE_BOX_2D determines if a point is inside a box in 2D.
• PS_CLIP defines a clipping polygon.
• PS_COLOR_LINE handles the line color.
• PS_COLOR_LINE_SET sets the line color.
• PS_COMMENT inserts a comment into the PostScript file.
• PS_DEFAULT sets the internal settings to their default values
• PS_FILE_CLOSE closes a PostScript file.
• PS_FILE_OPEN opens a new version of a PostScript file with a given name.
• PS_FONT_SIZE sets the font size.
• PS_LABEL prints a label at the current position.
• PS_LINE draws a line segment from (X1,Y1) to (X2,Y2).
• PS_LINE_CLOSED adds the graph of a closed line to a PostScript file.
• PS_LINE_WIDTH sets the line width.
• PS_MARK_DISK marks a point with a small filled disk.
• PS_MARK_POINT marks a point with a tiny point.
• PS_MOVETO "moves to" a new point, which becomes the current point.
• PS_PAGE_HEAD writes header information on a new page.
• PS_PAGE_TAIL writes tail information at the end of a page.
• PS_SETTING_INT sets, gets, or prints integer internal PS_WRITE parameters.
• PS_SETTING_REAL sets, gets, or prints real internal PS_WRITE parameters.
• R8_SWAP swaps two R8's.
• S_EQI is a case insensitive comparison of two strings for equality.
• S_TO_I4 reads an I4 from a string.
• S_TO_R8 reads an R8 from a string.
• TIMESTAMP prints the current YMDHMS date as a time stamp.
• TIMESTRING writes the current YMDHMS date into a string.
• VORONOI_EPS plots a Voronoi diagram.
• VORONOI_DATA_READ reads the data from a Voronoi file.
• VORONOI_HEADER_READ reads the header information from a Voronoi file.
• WORD_EXTRACT extracts the next word from a string.

You can go up one level to the FORTRAN90 source codes.