7.44 load_lattice_response_matrix

• type: setup command.
• function: read a previously-saved lattice-correction response matrix (produced by compute_lattice_response_matrix) and install it for use by a subsequent correct_lattice command, avoiding the cost of rebuilding the matrix.
• sequence: must follow run_setup.
• Command syntax, including use of equations and subcommands, is discussed in 7.2.

• filename — The (incomplete) name of the SDDS file written by a prior compute_lattice_response_matrix command. The file carries the parameter being adjusted (ElementParameter), the perturbation that was used to build it, and the full list of BPM and quadrupole elements (by name and occurrence); these are matched against the current beamline to install the matrix. An error is reported if any expected element is not present in the current beamline. The file’s CorrectionElements and CorrectionItems parameters (the family-list strings used when the matrix was built) are also loaded into the active correction state, so a subsequent correct_lattice may omit correction_elements and items and inherit them from the matrix file. When those parameters are restated on correct_lattice they must agree with the loaded values or the run aborts with an explicit diagnostic.
• verbosity — Higher values print more diagnostic information.

If either compute_lattice_response_matrix or load_lattice_response_matrix is given before correct_lattice, the precomputed matrix is used and the knob/BPM/item selection on correct_lattice is not required. When the user does restate correction_elements or items on correct_lattice, the values must match those carried by the matrix file or the run aborts. In all cases lower_limits and upper_limits may be supplied freely on correct_lattice to clamp the inherited knobs; their token count must agree with the inherited family count. If neither command provides a matrix, correct_lattice builds it itself according to its own use_perturbed_matrix control.