- type: major action command.
- function: find the transport matrix up to third order based on particle tracking, based on
method described in . Also find related quantities, such as chromaticity.
- sequence: must follow run_control.
- can use parallel resources (Pelegant)
- Command syntax, including use of equations and subcommands, is discussed in 7.2.
STRING output = NULL;
long output_order = 1;
STRING printout = NULL;
STRING printout_format = "%22.15e ";
long printout_order = 2;
double delta_x = 5e-5;
double delta_xp = 5e-5;
double delta_y = 5e-5;
double delta_yp = 5e-5;
double delta_s = 5e-5;
double delta_dp = 5e-5;
double accuracy_factor = 1e-12;
long center_on_orbit = 0;
long verbosity = 0;
long canonical_variables = 0;
long periodic = 1;
double beta_x = 1;
double alpha_x = 0;
double eta_x = 0;
double etap_x = 0;
double beta_y = 1;
double alpha_y = 0;
double eta_y = 0;
double etap_y = 0;
long n_points = 9;
long max_fit_order = 8;
- output — The (incomplete) name of a file for SDDS output.
- Recommended value: “%s.ana”.
- File contents: A series of pages, each consisting of a single data point containing the
centroid offsets for a single turn, the single-turn R matrix, the matched Twiss parameters,
tunes, and dispersion functions.
- printout — The (incomplete) name of a file for text output of the matrix.
- printout_format — The C-style formatting statement for the matrix elements. A space, comma, or
other separator should appear at the end of the string.
- delta_X — The amount by which to change the quantity X in computing the derivatives that give
the matrix elements.
- accuracy_factor — The fraction of the maximum absolute value of the final coordinate
that is considered meaningful. Used to estimate errors and eliminate spurious matrix
- canonical_variables — If non-zero, the matrix is expressed in terms of canonical variables
(x,qx,y,qy,-s,δ) instead of the default (x,x′,y,y′,s,δ).
- center_on_orbit — A flag directing the expansion to be made about the closed orbit instead of the
- verbosity — The larger this value, the more output is printed during computations.
- printout_order — Order of the matrix to be printed to the printout file.
- periodic — If non-zero, system is assumed to be periodic and lattice functions, tunes,
chromaticities, etc are computed.
- beta_x, alpha_x, eta_x, etap_x, beta_y, alpha_y, eta_y, etap_y — If periodic=0, these are the
starting values for the lattice functions.
- n_points — Number of points in each phase-space dimension.
- max_fit_order — Maximum order of fits using in determining the matrix elements.