call p%descr(info, [iout, root, verbosity])
This method prints a description of the preconditioner p to the standard output or to a file. It must be called after hierachy_build and smoothers_build, or build, have been called.
Arguments
info | info >>>>>> development
class="cmtt-12">integer, intent(out). >>>>>> development
class="cmr-12">Error code. If no error, 0 is returned. See Section 7 for details. amold class(psb_x_base_sparse_mat), iout integer,>>>>>> development
class="cmtt-12"> intent(in), optional. The desired dynamic type for internal matrix components; this
=======
style="vertical-align:baseline;" id="TBL-16-4-"> The id of the file where the preconditioner description will be
>>>>>>> development
printed; the default is the standard output. |
call p%clone(pout,info)
Create a (deep) copy of the preconditioner object.
Arguments
pout | type(amg_xprec_type), intent(out). |
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| The copy of the preconditioner data structure. Note that x must be chosen according to the real/complex, single/double precision version of AMG4PSBLAS under use. |
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info | root | >>>>>> development class="cmtt-12">integer, intent(out). |
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| Error code. If no error, 0 is returned. See Section 7 for details. |
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sz = p%sizeof([global])
global | logical,in),>>>>>> development class="cmtt-12"> optional. |
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| Whether the global or local preconditioner memory occupation is ======= style="vertical-align:baseline;" id="TBL-16-6-"> |
| The id of the process where the preconditioner description >>>>>>> development will be printed; the default is psb_root_. |
call p%allocate_wrk(info[, vmold])
Allocate internal work vectors. Each application of the preconditioner uses a number of work vectors which are allocated internally as necessary; therefore allocation and deallocation of memory occurs multiple times during the execution of a Krylov method. In most cases this strategy is perfectly acceptable, but on some platforms, most notably GPUs, memory allocation is a slow operation, and the default behaviour would lead to a slowdown. This method allows to trade space for time by preallocating the internal workspace outside of the invocation of a Krylov method. When using GPUs or other specialized devices, the vmold argument is also necessary to ensure the internal work vectors are of the appropriate dynamic type to exploit the accelerator hardware; when allocation occurs internally this is taken care of based on the dynamic type of the x argument to the apply method.
Arguments
info | verbosity | >>>>>> development class="cmtt-12">integer, intent(out). |
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| Error code. If no error, 0 is returned. See Section 7 for details. |
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vmold | class(psb_x_base_vect_type), intent(>>>>>> development class="cmtt-12">in), optional. |
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| The desired dynamic type for internal vector components; this allows e.g. running on GPUs. |
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call p%free_wrk(info)
Deallocate internal work vectors.
Arguments
info | integer, intent(out). |
| Error code. If no error, 0 is returned. See Section 7 for details. |
The verbosity level of the description. Default value is 0. For values higher than 0, it prints out further information, e.g., for a distributed multilevel preconditioner the size of the coarse matrices on every process.