@pimms.calc('<STR_LIT>')<EOL>def calc_anchors(preregistration_map, model, model_hemi,<EOL>scale=<NUM_LIT:1>, sigma=Ellipsis, radius_weight=<NUM_LIT:0>, field_sign_weight=<NUM_LIT:0>,<EOL>invert_rh_field_sign=False):
wgts = preregistration_map.prop('<STR_LIT>')<EOL>rads = preregistration_map.prop('<STR_LIT>')<EOL>if np.isclose(radius_weight, <NUM_LIT:0>): radius_weight = <NUM_LIT:0><EOL>ancs = retinotopy_anchors(preregistration_map, model,<EOL>polar_angle='<STR_LIT>',<EOL>eccentricity='<STR_LIT>',<EOL>radius='<STR_LIT>',<EOL>weight=wgts, weight_min=<NUM_LIT:0>, <EOL>radius_weight=radius_weight, field_sign_weight=field_sign_weight,<EOL>scale=scale,<EOL>invert_field_sign=(model_hemi == '<STR_LIT>' and invert_rh_field_sign),<EOL>**({} if sigma is Ellipsis else {'<STR_LIT>':sigma}))<EOL>return ancs<EOL>
calc_anchors is a calculator that creates a set of anchor instructions for a registration.

Required afferent parameters:
  @ invert_rh_field_sign May be set to True (default is False) to indicate that the right
    hemisphere's field signs will be incorrect relative to the model; this generally should be
    used whenever invert_rh_angle is also set to True.