- type: major action command.
- function: compute frequency map from tracking Note that the number of turns tracked is set
by the run_control command.
- can use parallel resources (Pelegant)
- Command syntax, including use of equations and subcommands, is discussed in 7.2.
STRING output = NULL;
double xmin = -0.1;
double xmax = 0.1;
double ymin = 1e-6;
double ymax = 0.1;
double delta_min = 0;
double delta_max = 0;
long nx = 21;
long ny = 21;
long ndelta = 1;
long verbosity = 1;
long include_changes = 0;
long quadratic_spacing = 0;
long full_grid_output = 0;
- output — The (incomplete) name of an SDDS file to send output to. Recommended value:
“%s.fma”. For the parallel version, particles will be listed in essentially random order. If
needed, sddssort can be used to sort particles by initial coordinates.
- xmin, xmax — Limits of grid of initial x coordinates for tracking.
- ymin, ymax — Limits of grid of initial y coordinates for tracking. ymin should be a small,
positive value so that there is some betatron oscillation from which to get the tune.
- delta_min, delta_max — Limits of grid of initial δ coordinates for tracking. Note that
particles are not centered around the dispersive closed orbit. Hence, the tracking is appropriate
to simulation of dynamics from a touschek scattering event.
- nx — Number of values of x coordinate in the grid.
- ny — Number of values of y coordinate in the grid.
- ndelta — Number of values of δ coordinate in the grid.
- verbosity — If nonzero, prints possibly useful information while running.
- include_changes — If nonzero, then computes not only the tunes, but also the changes in the
tunes. This is expressed in terms of the diffusion, which is defined as
where Δνx and Δνy are respectively the differences in x and y tunes from the first and second half
of the tracking (the total number of turns is equal to the value set in run_setup). The diffusion
is also computed. dr is the more conventional quantity, computed by programs such as TRACY and
- quadratic_spacing — If non-zero, the spacing of points is quadratic rather than linear, thus
emphasizing the higher amplitude regions.
- full_grid_output — If non-zero, all grid points are represented in the output file, even if tracking
or tune determination failed. This makes it possible to plot with programs (e.g., sddscontour) that
require a strictly uniform grid.