steering_element

• type: setup command.
• function: setup for use of a given parameter of a given element as a steering corrector.
• N.B.: any use of this command disables the built-in definition of HKICK, VKICK, and HVKICK elements as steering elements. For trajectory correction, this facility works without any effort by the user. It will not work for orbit correction unless the user does two things: First, all correction elements for each plane must be the same. Second, the gain must be less than the ratio of the angle kick to unit parameter change for the element.

&steering_element
    STRING name = NULL;
    STRING element_type = NULL;
    STRING item = NULL;
    STRING plane = "h";
    double tweek = 1e-3;
    double limit = 0;
&end

• name -- Optional: the (possibly wild-carded) name of the element to add to the steering list. If not given, then element_type must be given.
• element_type -- Optional: the (possibly wild-carded) name of the element type to add to the steering list. If not given, then name must be given.
• item -- The parameter of the element to be varied.
• plane -- May be either ``h'' or ``v'', for horizontal or vertical correction.
• tweek -- The amount by which to change the item to compute the steering strength.
• limit -- The maximum allowed absolute value of the item.