.. highlight:: fortran

FORTRAN Library Interface
-------------------------

.. versionadded:: 2.0

The next enumerations and functions are declared in ``primme_svds_f77.h``.

sprimme_svds_f77
""""""""""""""""

.. f:subroutine:: sprimme_svds_f77(svals, svecs, resNorms, primme_svds, ierr)

   Solve a real singular value problem using single precision.

   All arrays should be hosted on CPU. The computations are performed on CPU (see :f:func:`magma_sprimme_svds_f77` for using GPUs).
   
   :param svals(*): (output) array at least of size |SnumSvals| to store the
      computed singular values; all processes in a parallel run return this local array with the same values.
   :type svals: real

   :param svecs(*): array at least of size (|SmLocal| + |SnLocal|) times (|SnumOrthoConst| + |SnumSvals|)
      to store column-wise the (local part for this process of the) computed left singular vectors
      and the right singular vectors.
   :type svecs: real

   :param resNorms(*): array at least of size |SnumSvals| to store the
      residual norms of the computed triplets; all processes in parallel run return this local array with
      the same values.
   :type resNorms: real

   :param ptr primme_svds: parameters structure.

   :param integer ierr: (output) error indicator; see :ref:`error-codes-svds`.

   On input, ``svecs`` should start with the content of the |SnumOrthoConst| left vectors,
   followed by the |SinitSize| left vectors, followed by the |SnumOrthoConst| right vectors and
   followed by the |SinitSize| right vectors.
 
   On return, the i-th left singular vector starts at svecs(( |SnumOrthoConst| + i - 1) \* |SmLocal| ).
   The i-th right singular vector starts at svecs(( |SnumOrthoConst| + |SinitSize| )\* |SmLocal| + ( |SnumOrthoConst| + i - 1)\* |SnLocal| ).
   The first vector has i=1.
 
   All internal operations are performed at the same precision than ``svecs`` unless the user sets |SinternalPrecision| otherwise.

   The type and precision of the callbacks depends on the type and precision of `svecs`. See details for |SmatrixMatvec|, |SapplyPreconditioner|, |SglobalSumReal|, |SbroadcastReal|, and |SconvTestFun|.


cprimme_svds_f77
""""""""""""""""

.. f:subroutine:: cprimme_svds_f77(svals, svecs, resNorms, primme_svds, ierr)

   Solve a complex singular value problem using single precision.

   All arrays should be hosted on CPU. The computations are performed on CPU (see :f:func:`magma_cprimme_svds_f77` for using GPUs).
   
   :param svals(*): (output) array at least of size |SnumSvals| to store the
      computed singular values; all processes in a parallel run return this local array with the same values.
   :type svals: real

   :param svecs(*): array at least of size (|SmLocal| + |SnLocal|) times (|SnumOrthoConst| + |SnumSvals|)
      to store column-wise the (local part for this process of the) computed left singular vectors
      and the right singular vectors.
   :type svecs: complex

   :param resNorms(*): array at least of size |SnumSvals| to store the
      residual norms of the computed triplets; all processes in parallel run return this local array with
      the same values.
   :type resNorms: real

   :param ptr primme_svds: parameters structure.

   :param integer ierr: (output) error indicator; see :ref:`error-codes-svds`.

   On input, ``svecs`` should start with the content of the |SnumOrthoConst| left vectors,
   followed by the |SinitSize| left vectors, followed by the |SnumOrthoConst| right vectors and
   followed by the |SinitSize| right vectors.
 
   On return, the i-th left singular vector starts at svecs(( |SnumOrthoConst| + i - 1) \* |SmLocal| ).
   The i-th right singular vector starts at svecs(( |SnumOrthoConst| + |SinitSize| )\* |SmLocal| + ( |SnumOrthoConst| + i - 1)\* |SnLocal| ).
   The first vector has i=1.
 
   All internal operations are performed at the same precision than ``svecs`` unless the user sets |SinternalPrecision| otherwise.

   The type and precision of the callbacks depends on the type and precision of `svecs`. See details for |SmatrixMatvec|, |SapplyPreconditioner|, |SglobalSumReal|, |SbroadcastReal|, and |SconvTestFun|.

dprimme_svds_f77
""""""""""""""""

.. f:subroutine:: dprimme_svds_f77(svals, svecs, resNorms, primme_svds, ierr)

   Solve a real singular value problem using double precision.

   All arrays should be hosted on CPU. The computations are performed on CPU (see :f:func:`magma_dprimme_svds_f77` for using GPUs).
   
   :param svals(*): (output) array at least of size |SnumSvals| to store the
      computed singular values; all processes in a parallel run return this local array with the same values.
   :type svals: double precision

   :param svecs(*): array at least of size (|SmLocal| + |SnLocal|) times (|SnumOrthoConst| + |SnumSvals|)
      to store column-wise the (local part for this process of the) computed left singular vectors
      and the right singular vectors.
   :type svecs: double precision

   :param resNorms(*): array at least of size |SnumSvals| to store the
      residual norms of the computed triplets; all processes in parallel run return this local array with
      the same values.
   :type resNorms: double precision

   :param ptr primme_svds: parameters structure.

   :param integer ierr: (output) error indicator; see :ref:`error-codes-svds`.

   On input, ``svecs`` should start with the content of the |SnumOrthoConst| left vectors,
   followed by the |SinitSize| left vectors, followed by the |SnumOrthoConst| right vectors and
   followed by the |SinitSize| right vectors.
 
   On return, the i-th left singular vector starts at svecs(( |SnumOrthoConst| + i - 1) \* |SmLocal| ).
   The i-th right singular vector starts at svecs(( |SnumOrthoConst| + |SinitSize| )\* |SmLocal| + ( |SnumOrthoConst| + i - 1)\* |SnLocal| ).
   The first vector has i=1.
 
   All internal operations are performed at the same precision than ``svecs`` unless the user sets |SinternalPrecision| otherwise.

   The type and precision of the callbacks depends on the type and precision of `svecs`. See details for |SmatrixMatvec|, |SapplyPreconditioner|, |SglobalSumReal|, |SbroadcastReal|, and |SconvTestFun|.

zprimme_svds_f77
""""""""""""""""

.. f:subroutine:: zprimme_svds_f77(svals, svecs, resNorms, primme_svds, ierr)

   Solve a complex singular value problem using double precision.

   All arrays should be hosted on CPU. The computations are performed on CPU (see :f:func:`magma_zprimme_svds_f77` for using GPUs).
   
   :param svals(*): (output) array at least of size |SnumSvals| to store the
      computed singular values; all processes in a parallel run return this local array with the same values.
   :type svals: double precision

   :param svecs(*): array at least of size (|SmLocal| + |SnLocal|) times (|SnumOrthoConst| + |SnumSvals|)
      to store column-wise the (local part for this process of the) computed left singular vectors
      and the right singular vectors.
   :type svecs: complex double precision

   :param resNorms(*): array at least of size |SnumSvals| to store the
      residual norms of the computed triplets; all processes in parallel run return this local array with
      the same values.
   :type resNorms: double precision

   :param ptr primme_svds: parameters structure.

   :param integer ierr: (output) error indicator; see :ref:`error-codes-svds`.

   On input, ``svecs`` should start with the content of the |SnumOrthoConst| left vectors,
   followed by the |SinitSize| left vectors, followed by the |SnumOrthoConst| right vectors and
   followed by the |SinitSize| right vectors.
 
   On return, the i-th left singular vector starts at svecs(( |SnumOrthoConst| + i - 1) \* |SmLocal| ).
   The i-th right singular vector starts at svecs(( |SnumOrthoConst| + |SinitSize| )\* |SmLocal| + ( |SnumOrthoConst| + i - 1)\* |SnLocal| ).
   The first vector has i=1.
 
   All internal operations are performed at the same precision than ``svecs`` unless the user sets |SinternalPrecision| otherwise.

   The type and precision of the callbacks depends on the type and precision of `svecs`. See details for |SmatrixMatvec|, |SapplyPreconditioner|, |SglobalSumReal|, |SbroadcastReal|, and |SconvTestFun|.

magma_sprimme_svds_f77
""""""""""""""""""""""

.. f:subroutine:: magma_sprimme_svds_f77(svals, svecs, resNorms, primme_svds, ierr)

   Solve a real singular value problem using single precision.

   Most of the computations are performed on GPU (see :f:func:`sprimme_svds_f77` for using only the CPU).
   
   :param svals(*): (output) CPU array at least of size |SnumSvals| to store the
      computed singular values; all processes in a parallel run return this local array with the same values.
   :type svals: real

   :param svecs(*): GPU array at least of size (|SmLocal| + |SnLocal|) times (|SnumOrthoConst| + |SnumSvals|)
      to store column-wise the (local part for this process of the) computed left singular vectors
      and the right singular vectors.
   :type svecs: real

   :param resNorms(*): CPU array at least of size |SnumSvals| to store the
      residual norms of the computed triplets; all processes in parallel run return this local array with
      the same values.
   :type resNorms: real

   :param ptr primme_svds: parameters structure.

   :param integer ierr: (output) error indicator; see :ref:`error-codes-svds`.

   On input, ``svecs`` should start with the content of the |SnumOrthoConst| left vectors,
   followed by the |SinitSize| left vectors, followed by the |SnumOrthoConst| right vectors and
   followed by the |SinitSize| right vectors.
 
   On return, the i-th left singular vector starts at svecs(( |SnumOrthoConst| + i - 1) \* |SmLocal| ).
   The i-th right singular vector starts at svecs(( |SnumOrthoConst| + |SinitSize| )\* |SmLocal| + ( |SnumOrthoConst| + i - 1)\* |SnLocal| ).
   The first vector has i=1.
 
   All internal operations are performed at the same precision than ``svecs`` unless the user sets |SinternalPrecision| otherwise.

   The type and precision of the callbacks depends on the type and precision of `svecs`. See details for |SmatrixMatvec|, |SapplyPreconditioner|, |SglobalSumReal|, |SbroadcastReal|, and |SconvTestFun|.

   .. versionadded:: 3.0

magma_cprimme_svds_f77
""""""""""""""""""""""

.. f:subroutine:: magma_cprimme_svds_f77(svals, svecs, resNorms, primme_svds, ierr)

   Solve a complex singular value problem using single precision.

   Most of the computations are performed on GPU (see :f:func:`cprimme_svds_f77` for using only the CPU).
   
   :param svals(*): (output) CPU array at least of size |SnumSvals| to store the
      computed singular values; all processes in a parallel run return this local array with the same values.
   :type svals: real

   :param svecs(*): GPU array at least of size (|SmLocal| + |SnLocal|) times (|SnumOrthoConst| + |SnumSvals|)
      to store column-wise the (local part for this process of the) computed left singular vectors
      and the right singular vectors.
   :type svecs: complex

   :param resNorms(*): CPU array at least of size |SnumSvals| to store the
      residual norms of the computed triplets; all processes in parallel run return this local array with
      the same values.
   :type resNorms: real

   :param ptr primme_svds: parameters structure.

   :param integer ierr: (output) error indicator; see :ref:`error-codes-svds`.

   On input, ``svecs`` should start with the content of the |SnumOrthoConst| left vectors,
   followed by the |SinitSize| left vectors, followed by the |SnumOrthoConst| right vectors and
   followed by the |SinitSize| right vectors.
 
   On return, the i-th left singular vector starts at svecs(( |SnumOrthoConst| + i - 1) \* |SmLocal| ).
   The i-th right singular vector starts at svecs(( |SnumOrthoConst| + |SinitSize| )\* |SmLocal| + ( |SnumOrthoConst| + i - 1)\* |SnLocal| ).
   The first vector has i=1.
 
   All internal operations are performed at the same precision than ``svecs`` unless the user sets |SinternalPrecision| otherwise.

   The type and precision of the callbacks depends on the type and precision of `svecs`. See details for |SmatrixMatvec|, |SapplyPreconditioner|, |SglobalSumReal|, |SbroadcastReal|, and |SconvTestFun|.

   .. versionadded:: 3.0

magma_dprimme_svds_f77
""""""""""""""""""""""

.. f:subroutine:: magma_dprimme_svds_f77(svals, svecs, resNorms, primme_svds, ierr)

   Solve a real singular value problem using double precision.

   Most of the computations are performed on GPU (see :f:func:`dprimme_svds_f77` for using only the CPU).
   
   :param svals(*): (output) CPU array at least of size |SnumSvals| to store the
      computed singular values; all processes in a parallel run return this local array with the same values.
   :type svals: double precision

   :param svecs(*): GPU array at least of size (|SmLocal| + |SnLocal|) times (|SnumOrthoConst| + |SnumSvals|)
      to store column-wise the (local part for this process of the) computed left singular vectors
      and the right singular vectors.
   :type svecs: double precision

   :param resNorms(*): CPU array at least of size |SnumSvals| to store the
      residual norms of the computed triplets; all processes in parallel run return this local array with
      the same values.
   :type resNorms: double precision

   :param ptr primme_svds: parameters structure.

   :param integer ierr: (output) error indicator; see :ref:`error-codes-svds`.

   On input, ``svecs`` should start with the content of the |SnumOrthoConst| left vectors,
   followed by the |SinitSize| left vectors, followed by the |SnumOrthoConst| right vectors and
   followed by the |SinitSize| right vectors.
 
   On return, the i-th left singular vector starts at svecs(( |SnumOrthoConst| + i - 1) \* |SmLocal| ).
   The i-th right singular vector starts at svecs(( |SnumOrthoConst| + |SinitSize| )\* |SmLocal| + ( |SnumOrthoConst| + i - 1)\* |SnLocal| ).
   The first vector has i=1.
 
   All internal operations are performed at the same precision than ``svecs`` unless the user sets |SinternalPrecision| otherwise.

   The type and precision of the callbacks depends on the type and precision of `svecs`. See details for |SmatrixMatvec|, |SapplyPreconditioner|, |SglobalSumReal|, |SbroadcastReal|, and |SconvTestFun|.

   .. versionadded:: 3.0

magma_zprimme_svds_f77
""""""""""""""""""""""

.. f:subroutine:: magma_zprimme_svds_f77(svals, svecs, resNorms, primme_svds, ierr)

   Solve a complex singular value problem using double precision.

   Most of the computations are performed on GPU (see :f:func:`zprimme_svds_f77` for using only the CPU).
   
   :param svals(*): (output) CPU array at least of size |SnumSvals| to store the
      computed singular values; all processes in a parallel run return this local array with the same values.
   :type svals: double precision

   :param svecs(*): GPU array at least of size (|SmLocal| + |SnLocal|) times (|SnumOrthoConst| + |SnumSvals|)
      to store column-wise the (local part for this process of the) computed left singular vectors
      and the right singular vectors.
   :type svecs: complex double precision

   :param resNorms(*): CPU array at least of size |SnumSvals| to store the
      residual norms of the computed triplets; all processes in parallel run return this local array with
      the same values.
   :type resNorms: double precision

   :param ptr primme_svds: parameters structure.

   :param integer ierr: (output) error indicator; see :ref:`error-codes-svds`.

   On input, ``svecs`` should start with the content of the |SnumOrthoConst| left vectors,
   followed by the |SinitSize| left vectors, followed by the |SnumOrthoConst| right vectors and
   followed by the |SinitSize| right vectors.
 
   On return, the i-th left singular vector starts at svecs(( |SnumOrthoConst| + i - 1) \* |SmLocal| ).
   The i-th right singular vector starts at svecs(( |SnumOrthoConst| + |SinitSize| )\* |SmLocal| + ( |SnumOrthoConst| + i - 1)\* |SnLocal| ).
   The first vector has i=1.
 
   All internal operations are performed at the same precision than ``svecs`` unless the user sets |SinternalPrecision| otherwise.

   The type and precision of the callbacks depends on the type and precision of `svecs`. See details for |SmatrixMatvec|, |SapplyPreconditioner|, |SglobalSumReal|, |SbroadcastReal|, and |SconvTestFun|.

   .. versionadded:: 3.0

primme_svds_initialize_f77
""""""""""""""""""""""""""

.. f:subroutine:: primme_svds_initialize_f77(primme_svds, ierr)

   Set PRIMME SVDS parameters structure to the default values.

   After calling :f:func:`dprimme_svds_f77` (or a variant), call :f:func:`primme_svds_free_f77` to release allocated resources by PRIMME.

   :param ptr primme_svds: (output) parameters structure.

primme_svds_set_method_f77
""""""""""""""""""""""""""

.. f:subroutine:: primme_svds_set_method_f77(method, methodStage1, methodStage2, primme_svds, ierr)

   Set PRIMME SVDS parameters to one of the preset configurations.

   :param integer method: (input) preset configuration to compute the singular triplets; one of

      * |PRIMME_SVDS_default|, currently set as |PRIMME_SVDS_hybrid|.
      * |PRIMME_SVDS_normalequations|, compute the eigenvectors of :math:`A^*A` or :math:`A A^*`.
      * |PRIMME_SVDS_augmented|, compute the eigenvectors of the augmented matrix, :math:`\left(\begin{array}{cc} 0 & A^* \\ A & 0 \end{array}\right)`.
      * |PRIMME_SVDS_hybrid|, start with |PRIMME_SVDS_normalequations|; use the
        resulting approximate singular vectors as initial vectors for
        |PRIMME_SVDS_augmented| if the required accuracy was not achieved.

   :param primme_preset_method methodStage1: (input) preset method to compute the eigenpairs at the first stage; see available values at :f:func:`primme_set_method_f77`.

   :param primme_preset_method methodStage2: (input) preset method to compute the eigenpairs with
      the second stage of |PRIMME_SVDS_hybrid|; see available values at :f:func:`primme_set_method_f77`.

   :param ptr primme_svds: (input/output) parameters structure.

   :param integer ierr: (output) if 0, successful; if negative, something went wrong.

primme_svds_display_params_f77
""""""""""""""""""""""""""""""

.. f:subroutine:: primme_svds_display_params_f77(primme_svds)

   Display all printable settings of ``primme_svds`` into the file descriptor |SoutputFile|.

   :param ptr primme_svds: (input) parameters structure.

primme_svds_free_f77
""""""""""""""""""""

.. f:subroutine:: primme_svds_free_f77(primme_svds, ierr)

   Free memory allocated by PRIMME SVDS and delete all values set.

   :param ptr primme_svds: (input/output) parameters structure.

primme_svds_set_member_f77
""""""""""""""""""""""""""

.. f:subroutine:: primme_svds_set_member_f77(primme_svds, label, value, ierr)

   Set a value in some field of the parameter structure.

   :param ptr primme_svds: (input) parameters structure.

   :param integer label: field where to set value. One of:

     | :c:member:`PRIMME_SVDS_primme                         <primme_svds_params.primme>`
     | :c:member:`PRIMME_SVDS_primmeStage2                   <primme_svds_params.primmeStage2>`
     | :c:member:`PRIMME_SVDS_m                              <primme_svds_params.m>`
     | :c:member:`PRIMME_SVDS_n                              <primme_svds_params.n>`
     | :c:member:`PRIMME_SVDS_matrixMatvec                   <primme_svds_params.matrixMatvec>`
     | :c:member:`PRIMME_SVDS_matrixMatvec_type              <primme_svds_params.matrixMatvec_type>`
     | :c:member:`PRIMME_SVDS_applyPreconditioner            <primme_svds_params.applyPreconditioner>`
     | :c:member:`PRIMME_SVDS_applyPreconditioner_type       <primme_svds_params.applyPreconditioner_type>`
     | :c:member:`PRIMME_SVDS_numProcs                       <primme_svds_params.numProcs>`
     | :c:member:`PRIMME_SVDS_procID                         <primme_svds_params.procID>`
     | :c:member:`PRIMME_SVDS_mLocal                         <primme_svds_params.mLocal>`
     | :c:member:`PRIMME_SVDS_nLocal                         <primme_svds_params.nLocal>`
     | :c:member:`PRIMME_SVDS_commInfo                       <primme_svds_params.commInfo>`
     | :c:member:`PRIMME_SVDS_globalSumReal                  <primme_svds_params.globalSumReal>`
     | :c:member:`PRIMME_SVDS_globalSumReal_type             <primme_svds_params.globalSumReal_type>`
     | :c:member:`PRIMME_SVDS_broadcastReal                  <primme_svds_params.broadcastReal>`
     | :c:member:`PRIMME_SVDS_broadcastReal_type             <primme_svds_params.broadcastReal_type>`
     | :c:member:`PRIMME_SVDS_numSvals                       <primme_svds_params.numSvals>`
     | :c:member:`PRIMME_SVDS_target                         <primme_svds_params.target>`
     | :c:member:`PRIMME_SVDS_numTargetShifts                <primme_svds_params.numTargetShifts>`
     | :c:member:`PRIMME_SVDS_targetShifts                   <primme_svds_params.targetShifts>`
     | :c:member:`PRIMME_SVDS_method                         <primme_svds_params.method>`
     | :c:member:`PRIMME_SVDS_methodStage2                   <primme_svds_params.methodStage2>`
     | :c:member:`PRIMME_SVDS_matrix                         <primme_svds_params.matrix>`
     | :c:member:`PRIMME_SVDS_preconditioner                 <primme_svds_params.preconditioner>`
     | :c:member:`PRIMME_SVDS_locking                        <primme_svds_params.locking>`
     | :c:member:`PRIMME_SVDS_numOrthoConst                  <primme_svds_params.numOrthoConst>`
     | :c:member:`PRIMME_SVDS_aNorm                          <primme_svds_params.aNorm>`
     | :c:member:`PRIMME_SVDS_eps                            <primme_svds_params.eps>`
     | :c:member:`PRIMME_SVDS_precondition                   <primme_svds_params.precondition>`
     | :c:member:`PRIMME_SVDS_initSize                       <primme_svds_params.initSize>`
     | :c:member:`PRIMME_SVDS_maxBasisSize                   <primme_svds_params.maxBasisSize>`
     | :c:member:`PRIMME_SVDS_maxBlockSize                   <primme_svds_params.maxBlockSize>`
     | :c:member:`PRIMME_SVDS_maxMatvecs                     <primme_svds_params.maxMatvecs>`
     | :c:member:`PRIMME_SVDS_iseed                          <primme_svds_params.iseed>`
     | :c:member:`PRIMME_SVDS_printLevel                     <primme_svds_params.printLevel>`
     | :c:member:`PRIMME_SVDS_outputFile                     <primme_svds_params.outputFile>`
     | :c:member:`PRIMME_SVDS_internalPrecision              <primme_svds_params.internalPrecision>`
     | :c:member:`PRIMME_SVDS_convTestFun                    <primme_svds_params.convTestFun>`
     | :c:member:`PRIMME_SVDS_convTestFun_type               <primme_svds_params.convTestFun_type>`
     | :c:member:`PRIMME_SVDS_convtest                       <primme_svds_params.convtest>`
     | :c:member:`PRIMME_SVDS_monitorFun                     <primme_svds_params.monitorFun>`
     | :c:member:`PRIMME_SVDS_monitorFun_type                <primme_svds_params.monitorFun_type>`
     | :c:member:`PRIMME_SVDS_monitor                        <primme_svds_params.monitor>`
     | :c:member:`PRIMME_SVDS_queue                          <primme_svds_params.queue>`
     | :c:member:`PRIMME_SVDS_stats_numOuterIterations       <primme_svds_params.stats.numOuterIterations>`
     | :c:member:`PRIMME_SVDS_stats_numRestarts              <primme_svds_params.stats.numRestarts>`
     | :c:member:`PRIMME_SVDS_stats_numMatvecs               <primme_svds_params.stats.numMatvecs>`
     | :c:member:`PRIMME_SVDS_stats_numPreconds              <primme_svds_params.stats.numPreconds>`
     | :c:member:`PRIMME_SVDS_stats_numGlobalSum             <primme_svds_params.stats.numGlobalSum>`
     | :c:member:`PRIMME_SVDS_stats_numBroadcast             <primme_svds_params.stats.numBroadcast>`
     | :c:member:`PRIMME_SVDS_stats_volumeGlobalSum          <primme_svds_params.stats.volumeGlobalSum>`
     | :c:member:`PRIMME_SVDS_stats_volumeBroadcast          <primme_svds_params.stats.volumeBroadcast>`
     | :c:member:`PRIMME_SVDS_stats_elapsedTime              <primme_svds_params.stats.elapsedTime>`
     | :c:member:`PRIMME_SVDS_stats_timeMatvec               <primme_svds_params.stats.timeMatvec>`
     | :c:member:`PRIMME_SVDS_stats_timePrecond              <primme_svds_params.stats.timePrecond>`
     | :c:member:`PRIMME_SVDS_stats_timeOrtho                <primme_svds_params.stats.timeOrtho>`
     | :c:member:`PRIMME_SVDS_stats_timeGlobalSum            <primme_svds_params.stats.timeGlobalSum>`
     | :c:member:`PRIMME_SVDS_stats_timeBroadcast            <primme_svds_params.stats.timeBroadcast>`
     | :c:member:`PRIMME_SVDS_stats_lockingIssue             <primme_svds_params.stats.lockingIssue>`

   :param value: (input) value to set.

   .. note::

      **Don't use** this subroutine inside PRIMME SVDS's callback functions, e.g., |SmatrixMatvec| or
      |SapplyPreconditioner|, or in functions called by these functions.

primme_svdstop_get_member_f77
"""""""""""""""""""""""""""""

.. f:subroutine:: primme_svdstop_get_member_f77(primme_svds, label, value, ierr)

   Get the value in some field of the parameter structure.

   :param ptr primme_svds: (input) parameters structure.

   :param integer label: (input) field where to get value. One of
      the detailed in subroutine :f:func:`primmesvds_top_set_member_f77`.

   :param value: (output) value of the field.

   .. note::

      **Don't use** this subroutine inside PRIMME SVDS's callback functions, e.g., |SmatrixMatvec| or
      |SapplyPreconditioner|, or in functions called by these functions. In those cases use
      :f:func:`primme_svds_get_member_f77`.

   .. note::

      When ``label`` is one of ``PRIMME_SVDS_matrixMatvec``, ``PRIMME_SVDS_applyPreconditioner``, ``PRIMME_SVDS_commInfo``,
      ``PRIMME_SVDS_intWork``, ``PRIMME_SVDS_realWork``, ``PRIMME_SVDS_matrix`` and ``PRIMME_SVDS_preconditioner``,
      the returned ``value`` is a C pointer (``void*``). Use Fortran pointer or other extensions to deal with it.
      For instance::

         use iso_c_binding
         MPI_Comm comm

         comm = MPI_COMM_WORLD
         call primme_svds_set_member_f77(primme_svds, PRIMME_SVDS_commInfo, comm)
         ...
         subroutine par_GlobalSumDouble(x,y,k,primme_svds)
         use iso_c_binding
         implicit none
         ...
         MPI_Comm, pointer :: comm
         type(c_ptr) :: pcomm

         call primme_svds_get_member_f77(primme_svds, PRIMME_SVDS_commInfo, pcomm)
         call c_f_pointer(pcomm, comm)
         call MPI_Allreduce(x,y,k,MPI_DOUBLE,MPI_SUM,comm,ierr)

      Most users would not need to retrieve these pointers in their programs.

primme_svds_get_member_f77
""""""""""""""""""""""""""

.. f:subroutine:: primme_svds_get_member_f77(primme_svds, label, value, ierr)

   Get the value in some field of the parameter structure.

   :param ptr primme_svds: (input) parameters structure.

   :param integer label: (input) field where to get value. One of
      the detailed in subroutine :f:func:`primme_svdstop_set_member_f77`.

   :param value: (output) value of the field.

   .. note::

      Use this subroutine exclusively inside PRIMME SVDS's callback functions, e.g., |SmatrixMatvec|
      or |SapplyPreconditioner|, or in functions called by these functions. Otherwise, e.g.,
      from the main program, use the subroutine :f:func:`primme_svdstop_get_member_f77`.

   .. note::

      When ``label`` is one of ``PRIMME_SVDS_matrixMatvec``, ``PRIMME_SVDS_applyPreconditioner``, ``PRIMME_SVDS_commInfo``,
      ``PRIMME_SVDS_intWork``, ``PRIMME_SVDS_realWork``, ``PRIMME_SVDS_matrix`` and ``PRIMME_SVDS_preconditioner``,
      the returned ``value`` is a C pointer (``void*``). Use Fortran pointer or other extensions to deal with it.
      For instance::

         use iso_c_binding
         MPI_Comm comm

         comm = MPI_COMM_WORLD
         call primme_svds_set_member_f77(primme_svds, PRIMME_SVDS_commInfo, comm)
         ...
         subroutine par_GlobalSumDouble(x,y,k,primme_svds)
         use iso_c_binding
         implicit none
         ...
         MPI_Comm, pointer :: comm
         type(c_ptr) :: pcomm

         call primme_svds_get_member_f77(primme_svds, PRIMME_SVDS_commInfo, pcomm)
         call c_f_pointer(pcomm, comm)
         call MPI_Allreduce(x,y,k,MPI_DOUBLE,MPI_SUM,comm,ierr)

      Most users would not need to retrieve these pointers in their programs.

.. include:: epilog.inc