# NAG CL Interfacef12jzc (feast_​free)

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## 1Purpose

f12jzc part of the NAG FEAST suite. It is used to deallocate the memory used within the problem handle and to destroy the handle itself.

## 2Specification

 #include
 void f12jzc (void **handle, NagError *fail)
The function may be called by the names: f12jzc or nag_sparseig_feast_free.

## 3Description

Each initialized problem handle (e.g., by f12jac) should be deallocated to avoid memory leaks. Therefore, f12jzc should be called on all the handles which are no longer needed, typically after obtaining results from the solver. Please note that passing a handle which has not been properly initialized might cause unpredictable behaviour, including a crash of your program. See Section 5 in the F12 Chapter Introduction for more details about the NAG FEAST suite.

## 4References

Polizzi E (2009) Density-Matrix-Based Algorithms for Solving Eigenvalue Problems Phys. Rev. B. 79 115112

## 5Arguments

1: $\mathbf{handle}$void ** Input/Output
On entry: the handle to the problem. It needs to be initialized (e.g., by f12jac) and to hold a problem formulation compatible with f12jzc. It must not be changed between calls to the NAG FEAST suite.
On exit: the handle is destroyed and set to NULL.
2: $\mathbf{fail}$NagError * Input/Output
The NAG error argument (see Section 7 in the Introduction to the NAG Library CL Interface).

## 6Error Indicators and Warnings

NE_ALLOC_FAIL
Dynamic memory allocation failed.
See Section 3.1.2 in the Introduction to the NAG Library CL Interface for further information.
On entry, argument $⟨\mathit{\text{value}}⟩$ had an illegal value.
NE_HANDLE
The supplied handle was not initialized or has become corrupted.
NE_INTERNAL_ERROR
An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
See Section 7.5 in the Introduction to the NAG Library CL Interface for further information.
NE_NO_LICENCE
Your licence key may have expired or may not have been installed correctly.
See Section 8 in the Introduction to the NAG Library CL Interface for further information.

Not applicable.

## 8Parallelism and Performance

f12jzc is not threaded in any implementation.