correct

• type: setup command.
• function: set up for correction of the trajectory or closed orbit.

&correct
    STRING mode = "trajectory";
    STRING method = "global";
    STRING trajectory_output = NULL;
    STRING corrector_output = NULL;
    STRING statistics = NULL;
    double corrector_tweek[2] = {1e-3, 1e-3};
    double corrector_limit[2] = {0, 0};
    double correction_fraction[2] = {1, 1};
    double correction_accuracy[2] = {1e-6, 1e-6};
    double bpm_noise[2] = {0, 0};
    double bpm_noise_cutoff[2] = {1.0, 1.0};
    STRING bpm_noise_distribution[2] = {"uniform", "uniform"};
    long verbose = 1;
    long fixed_length = 0;
    long fixed_length_matrix = 0;
    long n_xy_cycles = 1;
    long n_iterations = 1;
    long prezero_correctors = 1;
    long track_before_and_after = 0;
    long start_from_centroid = 1;
    long use_actual_beam = 0;
    double closed_orbit_accuracy = 1e-12;
    long closed_orbit_iterations = 10;
    double closed_orbit_iteration_fraction = 1;
    long use_perturbed_matrix = 0;
&end

• mode -- Either ``trajectory'' or ``orbit'', indicating correction of a trajectory or a closed orbit.
• method -- For trajectories, may be ``one-to-one'' or ``global''. For closed orbit, must be ``global''.
• trajectory_output -- The (incomplete) name of an SDDS file to which the trajectories or orbits will be written. Recommended value: ``%s.traj'' or ``%s.orb''.
• corrector_output -- The (incomplete) name of an SDDS file to which information about the final corrector strengths will be written. Recommended value: ``%s.cor''.
• statistics -- The (incomplete) name of an SDDS file to which statistical information about the trajectories (or orbits) and corrector strengths will be written. Recommended value: ``%s.scor''.
• corrector_tweek[2] -- The amount by which to change the correctors in order to compute correction coefficients. [The word ``tweak'' is misspelled ``tweek'' in the code.]
• corrector_limit[2] -- The maximum strength allowed for a corrector.
• correction_fraction[2] -- The fraction of the computed correction strength to actually use for any one iteration.
• correction_accuracy[2] -- The desired accuracy of the correction in terms of the RMS BPM values.
• bpm_noise[2] -- The BPM noise level.
• bpm_noise_cutoff[2] -- Cutoff values for the random distributions of BPM noise.
• bpm_noise_distribution[2] -- May be either ``gaussian'', ``uniform'', or ``plus_or_minus''.
• verbose -- If non-zero, information about the correction is printed during computations.
• fixed_length -- Indicates that the closed orbit length should be kept the same as the design orbit length by changing the momentum offset of the beam.
• fixed_length_matrix -- Indicates that for fixed-length orbit correction, the fixed-length matrix should be computed and used. This will improve convergence but isn't always needed.
• n_xy_cycles -- Number of times to alternate between correcting the x and y planes.
• n_iterations -- Number of iterations of the correction for each x/y cycle.
• prezero_correctors -- Flag indicating whether to set the correctors to zero before starting.
• track_before_and_after -- Flag indicating whether tracking should be done both before and after correction.
• start_from_centroid -- Flag indicating that correction should start from the beam centroid. For orbit correction, only the beam momentum centroid is relevant.
• use_actual_beam -- Flag indicating that correction should employ tracking of the beam distribution rather than a single particle. This is valid for trajectory correction only.
• closed_orbit_accuracy -- Accuracy of closed orbit computation.
• closed_orbit_iterations -- Number of iterations of closed orbit computation.
• closed_orbit_iteration_fraction -- Fraction of change in closed orbit to use at each iteration.
• use_perturbed_matrix -- If nonzero, specifies that prior to each correction elegant shall recompute the response matrix. This is useful if the lattice is changing significantly between corrections.