Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 11/07/2023
Public

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?trnlsp_get

Retrieves the number of iterations, stop criterion, initial residual, and final residual.

Syntax

res = strnlsp_get(handle, iter, st_cr, r1, r2)

res = dtrnlsp_get(handle, iter, st_cr, r1, r2)

Include Files

  • Fortran: mkl_rci.fi, mkl_rci.f90

Description

The routine retrieves the current number of iterations, the stop criterion, the initial residual, and final residual.

The initial residual is the value of the functional (||y - f(x)||) of the initial x values provided by the user.

The final residual is the value of the functional (||y - f(x)||) of the final x resulting from the algorithm operation.

The st_cr parameter contains a number indicating the stop criterion:

st_cr Value

Description

1

The algorithm has exceeded the maximum number of iterations

2

Δ < eps(1)

3

||F(x)||2 < eps(2)

4

The Jacobian matrix is singular.

||J(x)(1:m,j)||2 < eps(3), j = 1, ..., n

5

||s||2 < eps(4)

6

||F(x)||2 - ||F(x) - J(x)s||2 < eps(5)

Note:

  • J(x) is the Jacobian matrix.

  • Δ is the trust-region area.

  • F(x) is the value of the functional.

  • s is the trial step.

Input Parameters

handle

Type INTEGER*8.

Output Parameters

iter

INTEGER. Contains the current number of iterations.

st_cr

INTEGER. Contains the stop criterion.

See the Description section for the parameter values and their meanings.

r1

REAL for strnlsp_get

DOUBLE PRECISION for dtrnlsp_get

Contains the residual, (||y - f(x)||) given the initial x.

r2

REAL for strnlsp_get

DOUBLE PRECISION for dtrnlsp_get

Contains the final residual, that is, the value of the functional (||y - f(x)||) of the final x resulting from the algorithm operation.

res

INTEGER. Indicates the task completion.

res = TR_SUCCESS - the routine completed the task normally.

TR_SUCCESS is defined in the mkl_rci.fi include file.