CVT_MOVIE
Animated CVT Algorithm

CVT_MOVIE is a MATLAB program which animates the generation of a Centroidal Voronoi Tessellation (CVT) dataset.

The data that the user may set includes:

• N, the number of points to generate,
• INIT, initialize the points:
  • file, by reading data from file;
  • 'GRID', picking points from a grid;
  • 'HALTON', from a Halton sequence;
  • 'RAND', using MATLAB's RAND function;
  • 'UNIFORM', using a simple uniform RNG;
• IT_MAX, the maximum number of iterations;
• IT_FIXED, the number of iterations for which each set of sample points should be used (between 1 and IT_MAX);
• SAMPLE, how to conduct the sampling:
  • 'GRID', picking points from a grid;
  • 'HALTON', from a Halton sequence;
  • 'RAND', using MATLAB's RAND function;
  • 'UNIFORM', using a simple uniform RNG;
• SAMPLE_NUM, the number of sampling points:
• MOVIE_NAME, the number the animation file to be created.

Animation:

You can see a sample AVI animation.

Licensing:

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

Languages:

CVT_MOVIE is available in a MATLAB version.

Related Data and Programs:

CVT_CIRCLE_UNIFORM, a MATLAB program which calculates a Centroidal Voronoi Tessellation (CVT) over a circle with uniform density.

CVTP_1D, a MATLAB program which estimates a periodic centroidal Voronoi Tessellation (CVTP) in the periodic interval [0,1], using a version of Lloyd's iteration.

FILE_NAME_SEQUENCE, a MATLAB program which demonstrates four ways to generate a sequence of filenames.

PEAK_MOVIE, a MATLAB program which creates the pieces of an animation, one frame at a time. Each frame is independently created and saved as a JPEG file.

Reference:

1. Franz Aurenhammer,
   Voronoi diagrams - a study of a fundamental geometric data structure,
   ACM Computing Surveys,
   Volume 23, Number 3, pages 345-405, September 1991.
2. Qiang Du, Vance Faber, Max Gunzburger,
   Centroidal Voronoi Tessellations: Applications and Algorithms,
   SIAM Review,
   Volume 41, 1999, pages 637-676.

Source Code:

• ch_cap.m capitalizes a single character.
• cvt_iterate.m takes one step of the CVT iteration.
• cvt_movie.m gets information from the user, creates the CVT and saves the animation.
• cvt_sample.m returns sample points.
• cvt_write.m writes a CVT dataset to a file.
• data_read.m reads data from a file.
• file_exist.m is true if a file exists.
• file_delete.m deletes a file.
• find_closest.m finds the Voronoi cell generator closest to a point X.
• get_seed.m returns a seed for the random number generator.
• halham_leap_check.m checks LEAP for a Halton or Hammersley sequence.
• halham_n_check.m checks N for a Halton or Hammersley sequence.
• halham_ndim_check.m checks NDIM for a Halton or Hammersley sequence.
• halham_seed_check.m checks SEED for a Halton or Hammersley sequence.
• halham_step_check.m checks STEP for a Halton or Hammersley sequence.
• halton_base_check.m checks BASE for a Halton sequence.
• i4_to_halton_sequence.m next N elements of an NDIM-dimensional Halton sequence
• prime.m returns the N-th prime number.
• r8mat_transpose_print.m prints the transpose of an R8MAT, with an optional title.
• r8mat_transpose_print_some.m prints the transpose of some of an R8MAT, with an optional title.
• r8mat_uniform_01.m returns a unit pseudorandom R8MAT.
• random_initialize.m initializes the MATLAB random number seed.
• s_eqi.m is TRUE if two strings are equal, ignoring case.
• s_len_trim.m returns the length of a string to the last nonblank.
• timestamp.m prints the current YMDHMS date as a timestamp.
• tuple_next_fast.m computes the next element of a tuple space, "fast".

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