PLOT_POINTS - Plot points

PLOT_POINTS reads an XY point file and creates plots of the points, the Delaunay triangulation and the Voronoi diagram. There is also an option to plot the triangulated Voronoi polygons.

Files you may copy include:

• plot_points.f90, the source code.

Data files and plots you may copy include:

• annulus_25.txt, a sample set of points in an annulus.
• annulus_25_dot.eps, the point plot.
• annulus_25_delaunay.eps, the Delaunay triangulation plot.
• annulus_25_voronoi.eps, the Voronoi diagram plot.
• brownian_100.txt, a set of points that simulate Brownian motion.
• circle_25.txt, a sample set of points in a circle.
• circle_25_dot.eps, the point plot.
• circle_25_delaunay.eps, the Delaunay triangulation plot.
• circle_25_voronoi.eps, the Voronoi diagram plot.
• grid_49.txt, a sample set of points on a grid.
• grid_49_dot.eps, the point plot.
• grid_49_delaunay.eps, the Delaunay triangulation plot.
• grid_49_voronoi.eps, the Voronoi diagram plot.
• lsup_303.txt, 303 points outline Lake Superior.
• lsup_303_dot.eps, the point plot.
• lsup_303_dash.eps, the line plot.
• repeats_17.txt, a sample set of points, with some repeated.
• repeats_17_dot.eps, the point plot.
• repeats_17_delaunay.eps, the Delaunay triangulation plot.
• repeats_17_trivor.eps, the triangulated Voronoi diagram plot.
• repeats_17_voronoi.eps, the Voronoi diagram plot.

Lili Ju gave me some data sets to analyze with this program. The data represents certain centroidal Voronoi tessellation generators, using certain density functions. Data files and plots you may copy include:

• ju1.txt, data set 1 from Lili Ju.
• ju1_dot.eps, a dot plot.
• ju1_delaunay.eps, the Delaunay triangulation.
• ju1_voronoi.eps, the Voronoi diagram.
• ju1_trivor.eps, the triangulated Voronoi diagram.
• ju2.txt, data set 2 from Lili Ju.
• ju2_dot.eps, a dot plot.
• ju2_delaunay.eps, the Delaunay triangulation.
• ju2_voronoi.eps, the Voronoi diagram.
• ju2_trivor.eps, the triangulated Voronoi diagram.
• ju3.txt, data set 3 from Lili Ju.
• ju3_dot.eps, a dot plot.
• ju3_delaunay.eps, the Delaunay triangulation.
• ju3_voronoi.eps, the Voronoi diagram.
• ju3_trivor.eps, the triangulated Voronoi diagram.

The list of routines includes:

• PLOT_POINTS plots the points in a file.
• ANGLE_CONTAINS_RAY_2D determines if an angle contains a ray, in 2D.
• ANGLE_DEG_2D returns the angle swept out between two rays in 2D.
• BOX_RAY_INT_2D: intersection ( box, ray ) in 2D.
• CH_CAP capitalizes a single character.
• CH_EQI is a case insensitive comparison of two characters for equality.
• CH_IS_DIGIT returns .TRUE. if a character is a decimal digit.
• CH_TO_DIGIT returns the integer value of a base 10 digit.
• DASH_PLOT plots a set of points, and connects them.
• DELAUNAY_PLOT plots the Delaunay triangulation of a pointset.
• DELAUNAY_PRINT prints out information defining a Delaunay triangulation.
• DIAEDG chooses a diagonal edge.
• DIGIT_INC increments a decimal digit.
• DIGIT_TO_CH returns the character representation of a decimal digit.
• DOT_PLOT plots the individual points.
• ENORMSQ0_2D computes the square of the Euclidean norm of (P1-P0) in 2D.
• FILE_COLUMN_COUNT counts the number of columns in the first line of a file.
• FILE_COLUMN_RANGE determines the minimum and maximum ranges of each column.
• FILE_NAME_EXT_GET determines the "extension" of a file name.
• FILE_NAME_EXT_SWAP replaces the current "extension" of a file name.
• FILE_NAME_INC generates the next filename in a series.
• GET_UNIT returns a free FORTRAN unit number.
• I_MODP returns the nonnegative remainder of integer division.
• I_SWAP swaps two integer values.
• I_WRAP forces an integer to lie between given limits by wrapping.
• IMAT_PRINT prints an integer matrix.
• IVEC_IDENTITY sets an integer vector to the identity vector A(I)=I.
• LINE_EXP2IMP_2D converts an explicit line to implicit form in 2D.
• LINE_EXP_NORMAL_2D computes the normal to a line in 2D.
• LINES_EXP_INT_2D determines where two explicit lines intersect in 2D.
• LINES_IMP_INT_2D determines where two implicit lines intersect in 2D.
• LRLINE determines where a point lies in relation to a directed line.
• POINTS_AVOID_POINT_ND checks if a point is "far" from a set of points in ND.
• POINTS_COUNT counts the valid point coordinates in a file.
• POINTS_READ reads point coordinates from a file.
• POINTS_THIN "thins" points that are too close to each other.
• RADIANS_TO_DEGREES converts an angle from radians to degrees.
• RHPSRT sorts points into lexicographic order using heap sort.
• RLESS determines whether P is lexicographically less than Q.
• RMAT_PRINT prints a real matrix.
• RMAT2_INVERSE inverts a 2 by 2 real matrix using Cramer's rule.
• RMAT_SOLVE uses Gauss-Jordan elimination to solve an N by N linear system.
• RSFTDW shifts A(*,MAP(L)) down a heap of size U.
• RTRIS2 constructs a Delaunay triangulation of 2D vertices.
• S_CAP replaces any lowercase letters by uppercase ones in a string.
• S_INDEX_LAST finds the LAST occurrence of a given substring.
• S_TO_R reads a real number from a string.
• S_TO_RVEC reads a real vector from a string.
• SWAPEC swaps diagonal edges until all triangles are Delaunay.
• TIMESTAMP prints the current YMDHMS date as a time stamp.
• TRIANGLE_CIRCUMCENTER_2D computes the circumcenter of a triangle in 2D.
• TRIANGLE_CONTAINS_POINT_2D finds if a point is inside a triangle in 2D.
• TRIVOR_PLOT plots the triangulated Voronoi diagram of a set of points in 2D.
• VBEDG determines which boundary edges are visible to a point.
• VORONOI_PLOT plots the Voronoi diagram of a set of points in 2D.
• WORD_COUNT counts the number of "words" in a string.

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