# ISC_2009 Issues in Scientific Computing, 2009

ISC_2009 is the homepage for material related to the course Math/CS 4414, Issues in Scientific Computing, 12:20-1:10, MWF, McBryde 329, which I team taught at Virginia Tech with Jeff Borggaard in the Fall 2009 semester.

I gave talks on:

Other material:

• beta_cdf_root.m seeks a root of the function BETA_CDF(X) - 0.7 = 0.0.
• car_dendrogram.png an image of the dendrogram showing a clustering based on car data.
• car_distance.txt a "distance" table, indicating the perceived difference or distance between various pairs of cars.
• car_pdist.txt the car "distance" table, rewritten as a vector containing only the data in the upper half of the distance matrix.
• center_of_mass.m a MATLAB function which generates 20 random points in the unit square and computes their center of mass.
• chain_letter_distance.txt a worksheet for the chain letter problem.
• chain_letter_tree.m a MATLAB program for the chain letter problem.
• chain_letter_tree_output.txt the chain letter distance matrix, as output from the chain letter program.
• cvd.m a MATLAB function which carries out 20 steps of the centroidal Voronoi algorithm on an M by N pixel array.
• cvd_01.png a map of the 30 regions, after 1 step of the centroidal Voronoi algorithm.
• cvd_02.png a map of the 30 regions, after 2 steps of the centroidal Voronoi algorithm.
• cvd_03.png a map of the 30 regions, after 3 steps of the centroidal Voronoi algorithm.
• cvd_04.png a map of the 30 regions, after 4 steps of the centroidal Voronoi algorithm.
• cvd_05.png a map of the 30 regions, after 5 steps of the centroidal Voronoi algorithm.
• cvd_10.png a map of the 30 regions, after 10 steps of the centroidal Voronoi algorithm.
• cvd_15.png a map of the 30 regions, after 15 steps of the centroidal Voronoi algorithm.
• cvd_20.png a map of the 30 regions, after 20 steps of the centroidal Voronoi algorithm.
• dawkins.txt a letter to the editor from Dawkins, discussing the idea that a chain letter is a kind of "meme".
• fminunc_example.m a MATLAB program which illustrates the use of FMINUNC for unconstrained minimization.
• gator.pgm a PGM (Portable Gray Map) file containing an image.
• integral_2d.m a MATLAB program which estimates the integral of a function over a 2D domain.
• integral_circle.m a MATLAB program which estimates the integral of a function F(X,Y) over a circle.
• invmodn.m a MATLAB function which calculates the inverse of an element B mod N.
• invmodn_test.m a MATLAB function which tests INVMODN.
• invmodn_test_output.txt the output from running INVMODN_TEST.
• km.m a MATLAB function which carries out the K-Means clustering algorithm.
• lcg.m a MATLAB program which illustrates how a linear congruential generator works, by illustrating how the line Y=13*X is folded back into the square [0,31]x[0,31] by the MOD function.
• luck_a.txt chain letter "A".
• luck_b.txt chain letter "B".
• luck_c.txt chain letter "C".
• luck_d.txt chain letter "D".
• luck_e.txt chain letter "E".
• luck_f.txt chain letter "F".
• luck_g.txt chain letter "G".
• luck_h.txt chain letter "H".
• luck_i.txt chain letter "I".
• luck_j.txt chain letter "J".
• luck_k.txt chain letter "K".
• normal_comparison.m a MATLAB function which compares the normal distribution and a sum of uniform random values.
• p9.txt the coordinates of 9 points in the plane.
• p36_points.png the image of 36 points in the plane.
• p36_voronoi.png the Voronoi diagram of 36 points in the plane.
• p36.txt the coordinates of 36 points in the plane.
• pdist_example.m a MATLAB script which shows how PDIST can compute a table of distances.
• pixel_area.m uses the P9.TXT data to estimate the areas of the regions nearest to each of the points.
• pixel_plot.m displays the areas of the regions nearest to each of the points in the P9.TXT data.
• scores.txt a set of test scores.
• simple_data_dendrogram.png an image of the dendrogram of simple data.
• simple_data.png an image of the locations of the simple data values.
• simple_data.txt a set of simple data, just a list of 2D points.