NAG FL Interface
e04tbf (handle_​enable)

1 Purpose

2 Specification

3 Description

4 References

5 Arguments

1: $\mathbf{handle}$ – Type (c_ptr) Input

On entry: the handle to the problem. It needs to be initialized (e.g., by e04raf) and must not be changed between calls to the NAG optimization modelling suite.

2: $\mathbf{comp}$ – Character(*) Input

On entry: the type of the component of the model to be enabled. comp is case insensitive.

$\mathbf{comp}=\text{'X'}$, $\text{'VAR'}$ or $\text{'VARIABLE'}$

Decision variables $x$.

$\mathbf{comp}=\text{'LC'}$ or $\text{'LINEAR CONSTRAINT'}$

Linear constraints (see e04rjf).

$\mathbf{comp}=\text{'QC'}$ or $\text{'QUADRATIC CONSTRAINT'}$

Quadratic constraints (see e04rsf and e04rtf).

$\mathbf{comp}=\text{'NLC'}$ or $\text{'NONLINEAR CONSTRAINT'}$

Nonlinear constraints (see e04rkf).

$\mathbf{comp}=\text{'CN'}$ or $\text{'CONE'}$

Quadratic or rotated quadratic cones (see e04rbf).

$\mathbf{comp}=\text{'MI'}$ or $\text{'MATRIX INEQUALITY'}$

Matrix inequality constraints (see e04rnf).

$\mathbf{comp}=\text{'NLS'}$ or $\text{'RESIDUAL'}$

Nonlinear residuals $r_j\left(x\right)$ in the nonlinear least squares objective function (see e04rmf).

Constraint: $\mathbf{comp}=\text{'X'}$, $\text{'VAR'}$, $\text{'VARIABLE'}$, $\text{'LC'}$, $\text{'LINEAR CONSTRAINT'}$, $\text{'QC'}$, $\text{'QUADRATIC CONSTRAINT'}$, $\text{'NLC'}$, $\text{'NONLINEAR CONSTRAINT'}$, $\text{'CN'}$, $\text{'CONE'}$, $\text{'MI'}$, $\text{'MATRIX INEQUALITY'}$, $\text{'NLS'}$ or $\text{'RESIDUAL'}$.

3: $\mathbf{lidx}$ – Integer Input

On entry: the number of elements in the index set.

Constraint: $\mathbf{lidx}\ge 1$.

4: $\mathbf{idx}\left(\mathbf{lidx}\right)$ – Integer array Input

On entry: the index set of components comp to be enabled. The elements may be supplied in any order.

Constraint: $1\le \mathbf{idx}\left(\mathit{i}\right)\le M$, for $\mathit{i}=1,2,\dots ,\mathbf{lidx}$, where $M$ is the total number of the given components (e.g., decision variables) in the model.

5: $\mathbf{ifail}$ – Integer Input/Output

On entry: ifail must be set to $0$, $-1$ or $1$ to set behaviour on detection of an error; these values have no effect when no error is detected.

A value of $0$ causes the printing of an error message and program execution will be halted; otherwise program execution continues. A value of $-1$ means that an error message is printed while a value of $1$ means that it is not.

If halting is not appropriate, the value $-1$ or $1$ is recommended. If message printing is undesirable, then the value $1$ is recommended. Otherwise, the value $-1$ is recommended. When the value $-\mathbf{1}$ or $\mathbf{1}$ is used it is essential to test the value of ifail on exit.

On exit: $\mathbf{ifail}=\mathbf{0}$ unless the routine detects an error or a warning has been flagged (see Section 6).

6 Error Indicators and Warnings

$\mathbf{ifail}=1$

The supplied handle does not define a valid handle to the data structure for the NAG optimization modelling suite. It has not been properly initialized or it has been corrupted.

$\mathbf{ifail}=2$

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

$\mathbf{ifail}=5$

On entry, $\mathbf{lidx}=⟨\mathit{\text{value}}⟩$.
Constraint: $\mathbf{lidx}\ge 1$.

$\mathbf{ifail}=6$

On entry, $\mathbf{comp}=⟨\mathit{\text{value}}⟩$.
Constraint: $\mathbf{comp}=\text{'X'}$, $\text{'LC'}$, $\text{'QC'}$, $\text{'NLC'}$, $\text{'CN'}$, $\text{'MI'}$ or $\text{'NLS'}$.

$\mathbf{ifail}=8$

On entry, $\mathbf{comp}=⟨\mathit{\text{value}}⟩$, $i=⟨\mathit{\text{value}}⟩$, $\mathbf{idx}\left(i\right)=⟨\mathit{\text{value}}⟩$ and $M=⟨\mathit{\text{value}}⟩$.
Constraint: $1\le \mathbf{idx}\left(i\right)\le M$.

$\mathbf{ifail}=9$

On entry, $\mathbf{comp}=⟨\mathit{\text{value}}⟩$ and $\mathbf{idx}\left(i\right)=⟨\mathit{\text{value}}⟩$.
This component has been deleted.

This error can only occur when trying to enable a cone constraint that has been deleted by setting its size to $0$ with e04rbf.

$\mathbf{ifail}=-99$

An unexpected error has been triggered by this routine. Please contact NAG.

See Section 7 in the Introduction to the NAG Library FL Interface for further information.

$\mathbf{ifail}=-399$

Your licence key may have expired or may not have been installed correctly.

See Section 8 in the Introduction to the NAG Library FL Interface for further information.

$\mathbf{ifail}=-999$

Dynamic memory allocation failed.

See Section 9 in the Introduction to the NAG Library FL Interface for further information.

7 Accuracy

8 Parallelism and Performance

9 Further Comments

10 Example