load_parameters

• type: setup command.
• function: load parameters for elements from an SDDS file.

&load_parameters
        STRING filename = NULL;
        STRING filename_list = NULL;
        STRING include_name_pattern = NULL;
        STRING exclude_name_pattern = NULL;
        STRING include_item_pattern = NULL;
        STRING exclude_item_pattern = NULL;
        STRING include_type_pattern = NULL;
        STRING exclude_type_pattern = NULL;
        long change_defined_values = 0;
        long clear_settings = 0;
        long allow_missing_elements = 0;
        long allow_missing_parameters = 0;
	long force_occurence_data = 0;
        long verbose = 0;
&end

• filename -- Name (possibly containing the ``of SDDS file from which to take data. The file must contain some of the following columns:
  • ElementName -- Required string column. The name of the element to change.
  • ElementParameter -- Required string column. The name of the parameter of the element to change.
  • ParameterValue -- Optional double column. If given, gives value of the parameter named in ElementParameter for element named in ElementName.
  • ParameterValueString -- Optional string column. If ParameterValue is not present, then this column must be present. The string data will be scanned, if necessary, to obtain a value for the parameter.
  • ParameterMode -- Optional string column. If given, for each row the value must be one of ``absolute'', ``differential'', ``ignore'', or ``fractional''. The meaning of these modes is as follows: absolute mode means the given value is used as the new value for the parameter; differential mode means the given value is added to the existing value for the parameter; ignore mode means the value is ignored; fractional mode means the existing value is increased by the product of the given value and the existing value (i.e., the given value is a fractional change).

  Unless change_defined_values is set, successive pages of the file are used for successive steps of the simulation. Several elegant commands generate output that may be used (on a subsequent run) with load_parameters; among these are the tune and chromaticity correction commands and the run_setup command (parameters output).

• filename_list -- A list of filenames, which may be given in place of filename. If used, each file in the list is treated as if it was separately supplied with an individual load_parameters command.

• include_name_pattern, exclude_name_pattern -- Wildcard patterns to be used in selecting, respectively, which elements to include and which to exclude from loading.

• include_item_pattern, exclude_item_pattern -- Wildcard patterns to be used in selecting, respectively, which items (i.e., which element parameters) to include and which to exclude from loading.

• include_type_pattern, exclude_type_pattern -- Wildcard patterns to be used in selecting, respectively, which element types (e.g., QUAD, DRIFT) to include and which to exclude from loading.

• change_defined_values -- Changes the defined values of the parameters. This means that when the lattice is saved (using save_lattice), the parameters will have the altered values. Also, if one wants to alter the values for all steps of the simulation, one must set this flag.

  Note that the ElementOccurence data is normally ignored if change_defined_values is nonzero. This is because there is only one definition of each element, even if it is used multiple times. This behavior can be altered with the next control.

• force_occurence_data -- If set, then occurence data is used even in change_defined_values mode.

• clear_settings -- If set, clear all settings and files being used for loading parameters.

• allow_missing_elements -- If set, allow elements in the file that are not in the lattice. In this case, the nonapplicable data is simply ignored.

• allow_missing_parameters -- If set, it is not an error if any element in the lattice lacks a parameter that exists in the file.

• verbose -- If set, provide informational printouts about changes to parameters.