Example 5.4 (An application from physics)

Return to the main page.


Software
The computations described below were performed using Bertini version 1.4 and Matlab version R2012b in a 64-bit Linux environment. The instructions below assume that the user already has these or similar versions installed. Note that the Bertini commands are written here to run in serial, but it would be advisable to run these commands in parallel if the computing environment is set up for it (e.g. mpirun bertini input instead of bertini input).
Directions
  • Download Example5_4.zip and extract the files in an empty directory.
  • At the command line, run:
    bertini input.sliceC
    cp witness_data witness_data_copy
    Note: if the output shows fewer than 8 components, then repeat this step and/or use stricter configuration settings.
  • At the command line, run:
    bertini input.sliceW
    cp finite_solutions finite_solutions_copy
    cp finite_solutions member_points
    cp finite_solutions witness_points_fiber
  • At the command line, run:
    cp witness_data_copy witness_data
    bertini input.membership
    cp incidence_matrix incidence_matrix_copy
  • In Matlab, run:
    incidence_matrix_to_files
  • At the command line, run:
    bertini input.eval fiber_points.1; mv function image_points.1
    ...
    bertini input.eval fiber_points.8; mv function image_points.8
  • At the command line, run:
    cp witness_data_copy witness_data
    bertini input.sampleC
    When prompted, answer with:
    1, 0, 5000, 0, fiber_sample.1
    Repeat 7 more times, answering the prompts with:
    1, 1, 5000, 0, fiber_sample.2
    ...
    1, 7, 5000, 0, fiber_sample.8
    Note: In this step, it may be possible to get accurate results with fewer sample points (e.g. 1000), but here we sample 5000 for better numerical stability.
  • At the command line, run:
    bertini input.eval fiber_sample.1; mv function image_sample.1
    ...
    bertini input.eval fiber_sample.8; mv function image_sample.8
  • In Matlab, run:
    testacm
    When prompted, answer with:
    image_points.1, image_sample.1, 5
    Repeat 7 more times, answering the prompts with:
    image_points.2, image_sample.2, 5
    ...
    image_points.8, image_sample.8, 5


Return to the main page.