Class 'constraints': a set of constraints
constraints
is an S4 class for representing a set of constraints and its associated objects.
class
See constraints-operators
for object manipulation functions.
constraints
: a data.frame
containing the constraint specifications.
list_constraints
: a list containing the constraint
object representation of each constraint.
pool
: the item_pool
object associated with the constraints.
item_attrib
: the item_attrib
object associated with the constraints.
st_attrib
: the st_attrib
object associated with the constraints.
test_length
: the test length specified in the constraints.
nv
: the number of decision variables. Equals ni + ns
.
ni
: the number of items to search from.
ns
: the number of stimulus to search from.
id
: the item/stimulus ID string of each item/stimulus.
index,mat,dir,rhs
: these represent MIP-format constraints. A single MIP-format constraint is associated with a value in index
, a row in mat
, a value in rhs
, and a value in dir
.
* the **i**-th value of `index` represents which constraint specification in the `constraints` argument it was translated from.
* the **i**-th row of `mat` represents LHS coefficients to use on decision variables in the **i**-th MIP-format constraint.
* the **i**-th value of `rhs` represents RHS values to use in the **i**-th MIP-format constraint.
* the **i**-th value of `dir` represents the imposed constraint between LHS and RHS.
set_based
: TRUE
if the constraint is set-based. FALSE
otherwise.
item_order
: the item attribute of each item to use in imposing an item order constraint, if any.
item_order_by
: the name of the item attribute to use in imposing an item order constraint, if any.
stim_order
: the stimulus attribute of each stimulus to use in imposing a stimulus order constraint, if any.
stim_order_by
: the name of the stimulus attribute to use in imposing a stimulus order constraint, if any.
item_index_by_stimulus
: a list containing item indices of each stimulus.
stimulus_index_by_item
: the stimulus indices of each item.