# naginterfaces.library.opt.handle_​set_​linconstr_​coeff¶

naginterfaces.library.opt.handle_set_linconstr_coeff(handle, idlc, icolbj, bij)[source]

handle_set_linconstr_coeff is a part of the NAG optimization modelling suite and sets or modifies a single element in the linear constraint matrix of the problem.

For full information please refer to the NAG Library document for e04tj

https://www.nag.com/numeric/nl/nagdoc_28.6/flhtml/e04/e04tjf.html

Parameters
handleHandle

The handle to the problem. It needs to be initialized (e.g., by handle_init()) and must not be changed between calls to the NAG optimization modelling suite.

idlcint

, the number of the linear constraint, i.e., the row index of the element in the linear constraint matrix to be changed.

icolbjint

, the column (variable) index of the element .

bijfloat

, the new value of the element in the linear constraint matrix .

Raises
NagValueError
(errno )

has not been initialized.

(errno )

does not belong to the NAG optimization modelling suite, has not been initialized properly or is corrupted.

(errno )

has not been initialized properly or is corrupted.

(errno )

The problem cannot be modified right now, the solver is running.

(errno )

There are no linear constraints in the problem.

(errno )

On entry, and .

Constraint: .

(errno )

On entry, and .

Constraint: .

Notes

After the model has been fully or partially built by calling functions of the NAG optimization modelling suite, handle_set_linconstr_coeff may be used to set or modify a single element in the sparse linear constraint matrix previously defined by handle_set_linconstr(). This might be particularly helpful when a linear constraint needs to be extended after new variables have been added to the model by handle_add_vars().

See the E04 Introduction for more details about the NAG optimization modelling suite.