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<div class="title">amg.cpp</div> </div>
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<p>This tutorial shows the use of algebraic multigrid (AMG) preconditioners. </p>
<dl class="section warning"><dt>Warning</dt><dd>AMG is currently only experimentally available with the OpenCL backend and depends on Boost.uBLAS</dd></dl>
<p>We start with some rather general includes and preprocessor variables: </p>
<div class="fragment"><div class="line"><span class="preprocessor">#include "<a class="code" href="vector_8hpp.html">viennacl/vector.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="coordinate__matrix_8hpp.html">viennacl/coordinate_matrix.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="compressed__matrix_8hpp.html">viennacl/compressed_matrix.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="ilu_8hpp.html">viennacl/linalg/ilu.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="cg_8hpp.html">viennacl/linalg/cg.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="bicgstab_8hpp.html">viennacl/linalg/bicgstab.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="matrix__market_8hpp.html">viennacl/io/matrix_market.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="norm__2_8hpp.html">viennacl/linalg/norm_2.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="matrix__generation_8hpp.html">viennacl/tools/matrix_generation.hpp</a>"</span></div>
</div><!-- fragment --><p> Import the AMG functionality: </p>
<div class="fragment"><div class="line"><span class="preprocessor">#include "<a class="code" href="amg_8hpp.html">viennacl/linalg/amg.hpp</a>"</span></div>
</div><!-- fragment --><p> Some more includes: </p>
<div class="fragment"><div class="line"><span class="preprocessor">#include <iostream></span></div>
<div class="line"><span class="preprocessor">#include <vector></span></div>
<div class="line"><span class="preprocessor">#include <ctime></span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="vector-io_8hpp.html">vector-io.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="timer_8hpp.html">viennacl/tools/timer.hpp</a>"</span></div>
</div><!-- fragment --> <h2>Part 1: Worker routines</h2>
<h3>Run the Solver</h3>
<p>Runs the provided solver specified in the <code>solver</code> object with the provided preconditioner <code>precond</code> </p>
<div class="fragment"><div class="line"><span class="keyword">template</span><<span class="keyword">typename</span> MatrixType, <span class="keyword">typename</span> VectorType, <span class="keyword">typename</span> SolverTag, <span class="keyword">typename</span> PrecondTag></div>
<div class="line"><span class="keywordtype">void</span> <a name="a0"></a><a class="code" href="solver_8cpp.html#afadbea4317c8f42f54d4622cf0a1829f">run_solver</a>(MatrixType <span class="keyword">const</span> & matrix, VectorType <span class="keyword">const</span> & rhs, VectorType <span class="keyword">const</span> & ref_result, SolverTag <span class="keyword">const</span> & solver, PrecondTag <span class="keyword">const</span> & precond)</div>
<div class="line">{</div>
<div class="line"> VectorType result(rhs);</div>
<div class="line"> VectorType residual(rhs);</div>
<div class="line"></div>
<div class="line"> <a name="_a1"></a><a class="code" href="classviennacl_1_1tools_1_1timer.html">viennacl::tools::timer</a> timer;</div>
<div class="line"> timer.<a name="a2"></a><a class="code" href="classviennacl_1_1tools_1_1timer.html#ac3e360cdcecfb05861baa2800e4f2888">start</a>();</div>
<div class="line"> result = <a name="a3"></a><a class="code" href="namespaceviennacl_1_1linalg.html#a6e9b329b64ac782e6a5687ad2fc47a2a">viennacl::linalg::solve</a>(matrix, rhs, solver, precond);</div>
<div class="line"> <a name="a4"></a><a class="code" href="namespaceviennacl_1_1backend.html#a3707340b27c535438e213e3879b0f0a4">viennacl::backend::finish</a>();</div>
<div class="line"> std::cout << <span class="stringliteral">" > Solver time: "</span> << timer.<a name="a5"></a><a class="code" href="classviennacl_1_1tools_1_1timer.html#af44313f16c89e97704c90b1ebcc17bca">get</a>() << std::endl;</div>
<div class="line"> residual -= <a name="a6"></a><a class="code" href="namespaceviennacl_1_1linalg.html#aa18d10f8a90e38bd9ff43c650fc670ef">viennacl::linalg::prod</a>(matrix, result);</div>
<div class="line"> std::cout << <span class="stringliteral">" > Relative residual: "</span> << <a name="a7"></a><a class="code" href="namespaceviennacl_1_1linalg.html#ae46f15d01c01f92a153b3f555a15096b">viennacl::linalg::norm_2</a>(residual) / <a class="code" href="namespaceviennacl_1_1linalg.html#ae46f15d01c01f92a153b3f555a15096b">viennacl::linalg::norm_2</a>(rhs) << std::endl;</div>
<div class="line"> std::cout << <span class="stringliteral">" > Iterations: "</span> << solver.iters() << std::endl;</div>
<div class="line"> result -= ref_result;</div>
<div class="line"> std::cout << <span class="stringliteral">" > Relative deviation from result: "</span> << <a class="code" href="namespaceviennacl_1_1linalg.html#ae46f15d01c01f92a153b3f555a15096b">viennacl::linalg::norm_2</a>(result) / <a class="code" href="namespaceviennacl_1_1linalg.html#ae46f15d01c01f92a153b3f555a15096b">viennacl::linalg::norm_2</a>(ref_result) << std::endl;</div>
<div class="line">}</div>
</div><!-- fragment --> <h3>Compare AMG preconditioner for uBLAS and ViennaCL types</h3>
<p>The AMG implementations in ViennaCL can be used with uBLAS types as well as ViennaCL types. This function compares the two in terms of execution time. </p>
<div class="fragment"><div class="line"><span class="keyword">template</span><<span class="keyword">typename</span> ScalarType></div>
<div class="line"><span class="keywordtype">void</span> run_amg(<a name="_a8"></a><a class="code" href="classviennacl_1_1linalg_1_1cg__tag.html">viennacl::linalg::cg_tag</a> & cg_solver,</div>
<div class="line"> <a name="_a9"></a><a class="code" href="classviennacl_1_1vector.html">viennacl::vector<ScalarType></a> & vcl_vec,</div>
<div class="line"> <a class="code" href="classviennacl_1_1vector.html">viennacl::vector<ScalarType></a> & vcl_result,</div>
<div class="line"> <a name="_a10"></a><a class="code" href="classviennacl_1_1compressed__matrix.html">viennacl::compressed_matrix<ScalarType></a> & vcl_compressed_matrix,</div>
<div class="line"> std::string info,</div>
<div class="line"> <a name="_a11"></a><a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html">viennacl::linalg::amg_tag</a> & amg_tag)</div>
<div class="line">{</div>
<div class="line"> std::cout << <span class="stringliteral">"-- CG with AMG preconditioner, "</span> << info << <span class="stringliteral">" --"</span> << std::endl;</div>
<div class="line"></div>
<div class="line"> <a name="_a12"></a><a class="code" href="classviennacl_1_1linalg_1_1amg__precond.html">viennacl::linalg::amg_precond<viennacl::compressed_matrix<ScalarType></a> > vcl_amg(vcl_compressed_matrix, amg_tag);</div>
<div class="line"> std::cout << <span class="stringliteral">" * Setup phase (ViennaCL types)..."</span> << std::endl;</div>
<div class="line"> <a class="code" href="classviennacl_1_1tools_1_1timer.html">viennacl::tools::timer</a> timer;</div>
<div class="line"> timer.<a class="code" href="classviennacl_1_1tools_1_1timer.html#ac3e360cdcecfb05861baa2800e4f2888">start</a>();</div>
<div class="line"> vcl_amg.setup();</div>
<div class="line"> <a class="code" href="namespaceviennacl_1_1backend.html#a3707340b27c535438e213e3879b0f0a4">viennacl::backend::finish</a>();</div>
<div class="line"> std::cout << <span class="stringliteral">" > Setup time: "</span> << timer.<a class="code" href="classviennacl_1_1tools_1_1timer.html#af44313f16c89e97704c90b1ebcc17bca">get</a>() << std::endl;</div>
<div class="line"></div>
<div class="line"> std::cout << <span class="stringliteral">" * CG solver (ViennaCL types)..."</span> << std::endl;</div>
<div class="line"> <a class="code" href="solver_8cpp.html#afadbea4317c8f42f54d4622cf0a1829f">run_solver</a>(vcl_compressed_matrix, vcl_vec, vcl_result, cg_solver, vcl_amg);</div>
<div class="line">}</div>
</div><!-- fragment --> <h2>Part 2: Run Solvers with AMG Preconditioners</h2>
<p>In this </p>
<div class="fragment"><div class="line"><span class="keywordtype">int</span> <a name="a13"></a><a class="code" href="tests_2src_2bisect_8cpp.html#ae66f6b31b5ad750f1fe042a706a4e3d4">main</a>(<span class="keywordtype">int</span> argc, <span class="keywordtype">char</span> **argv)</div>
<div class="line">{</div>
<div class="line"> std::string filename(<span class="stringliteral">"../examples/testdata/mat65k.mtx"</span>);</div>
<div class="line"> <span class="keywordflow">if</span> (argc == 2)</div>
<div class="line"> filename = argv[1];</div>
</div><!-- fragment --><p> Print some device info at the beginning. If there is more than one OpenCL device available, use the second device. </p>
<div class="fragment"><div class="line"> std::cout << std::endl;</div>
<div class="line"> std::cout << <span class="stringliteral">"----------------------------------------------"</span> << std::endl;</div>
<div class="line"> std::cout << <span class="stringliteral">" Device Info"</span> << std::endl;</div>
<div class="line"> std::cout << <span class="stringliteral">"----------------------------------------------"</span> << std::endl;</div>
<div class="line"></div>
<div class="line"><span class="preprocessor">#ifdef VIENNACL_WITH_OPENCL</span></div>
<div class="line"> <span class="comment">// Optional: Customize OpenCL backend</span></div>
<div class="line"> <a name="_a14"></a><a class="code" href="classviennacl_1_1ocl_1_1platform.html">viennacl::ocl::platform</a> pf = <a name="a15"></a><a class="code" href="namespaceviennacl_1_1ocl.html#ae1e931f6efd155240b33ca440dfcfef5">viennacl::ocl::get_platforms</a>()[0];</div>
<div class="line"> std::vector<viennacl::ocl::device> <span class="keyword">const</span> & devices = pf.<a name="a16"></a><a class="code" href="classviennacl_1_1ocl_1_1platform.html#afaa563522ebe9ce7b80ef02c40e7fe31">devices</a>();</div>
<div class="line"></div>
<div class="line"> <span class="comment">// Optional: Set first device to first context:</span></div>
<div class="line"> <a name="a17"></a><a class="code" href="namespaceviennacl_1_1ocl.html#add1725d48cfd159ce187e287369d1cdb">viennacl::ocl::setup_context</a>(0, devices[0]);</div>
<div class="line"></div>
<div class="line"> <span class="comment">// Optional: Set second device for second context (use the same device for the second context if only one device available):</span></div>
<div class="line"> <span class="keywordflow">if</span> (devices.size() > 1)</div>
<div class="line"> <a class="code" href="namespaceviennacl_1_1ocl.html#add1725d48cfd159ce187e287369d1cdb">viennacl::ocl::setup_context</a>(1, devices[1]);</div>
<div class="line"> <span class="keywordflow">else</span></div>
<div class="line"> <a class="code" href="namespaceviennacl_1_1ocl.html#add1725d48cfd159ce187e287369d1cdb">viennacl::ocl::setup_context</a>(1, devices[0]);</div>
<div class="line"></div>
<div class="line"> std::cout << <a name="a18"></a><a class="code" href="namespaceviennacl_1_1ocl.html#ac54d59a74deaccec81f64e738b856348">viennacl::ocl::current_device</a>().<a name="a19"></a><a class="code" href="classviennacl_1_1ocl_1_1device.html#a26a424782f982725453808a94763bd19">info</a>() << std::endl;</div>
<div class="line"> <a name="_a20"></a><a class="code" href="classviennacl_1_1context.html">viennacl::context</a> ctx(<a name="a21"></a><a class="code" href="namespaceviennacl_1_1ocl.html#a82c1aba632a7ee0991eee480d5340966">viennacl::ocl::get_context</a>(0));</div>
<div class="line"><span class="preprocessor">#else</span></div>
<div class="line"> <a class="code" href="classviennacl_1_1context.html">viennacl::context</a> ctx;</div>
<div class="line"><span class="preprocessor">#endif</span></div>
<div class="line"></div>
<div class="line"> <span class="keyword">typedef</span> <span class="keywordtype">double</span> <a name="a22"></a><a class="code" href="fft__1d_8cpp.html#ad5c19ca4f47d3f8ec21232a5af2624e5">ScalarType</a>; <span class="comment">// feel free to change this to double if supported by your device</span></div>
</div><!-- fragment --><p> Set up the matrices and vectors for the iterative solvers (cf. <a class="el" href="iterative_8cpp.html">iterative.cpp</a>) </p>
<div class="fragment"><div class="line"><a class="code" href="classviennacl_1_1compressed__matrix.html">viennacl::compressed_matrix<ScalarType></a> vcl_compressed_matrix(ctx);</div>
<div class="line"></div>
<div class="line"><span class="comment">//viennacl::tools::generate_fdm_laplace(vcl_compressed_matrix, points_per_dim, points_per_dim);</span></div>
<div class="line"><span class="comment">// Read matrix</span></div>
<div class="line">std::cout << <span class="stringliteral">"Reading matrix..."</span> << std::endl;</div>
<div class="line">std::vector< std::map<unsigned int, ScalarType> > read_in_matrix;</div>
<div class="line"><span class="keywordflow">if</span> (!<a name="a23"></a><a class="code" href="namespaceviennacl_1_1io.html#ad934125ed3dbe661e264bcd7d62b1048">viennacl::io::read_matrix_market_file</a>(read_in_matrix, filename))</div>
<div class="line">{</div>
<div class="line"> std::cout << <span class="stringliteral">"Error reading Matrix file"</span> << std::endl;</div>
<div class="line"> <span class="keywordflow">return</span> EXIT_FAILURE;</div>
<div class="line">}</div>
<div class="line"><a name="a24"></a><a class="code" href="namespaceviennacl.html#a10b7f8cf6b8864a7aa196d670481a453">viennacl::copy</a>(read_in_matrix, vcl_compressed_matrix);</div>
<div class="line">std::cout << <span class="stringliteral">"Reading matrix completed."</span> << std::endl;</div>
<div class="line"></div>
<div class="line"><a class="code" href="classviennacl_1_1vector.html">viennacl::vector<ScalarType></a> vcl_vec(vcl_compressed_matrix.size1(), ctx);</div>
<div class="line"><a class="code" href="classviennacl_1_1vector.html">viennacl::vector<ScalarType></a> vcl_result(vcl_compressed_matrix.size1(), ctx);</div>
<div class="line"></div>
<div class="line">std::vector<ScalarType> std_vec, std_result;</div>
<div class="line"></div>
<div class="line"></div>
<div class="line"><span class="comment">// rhs and result vector:</span></div>
<div class="line">std_vec.<a name="a25"></a><a class="code" href="classviennacl_1_1vector.html#a1b73aadf0c7b6c0028fd237ebb30c767">resize</a>(vcl_compressed_matrix.size1());</div>
<div class="line">std_result.<a class="code" href="classviennacl_1_1vector.html#a1b73aadf0c7b6c0028fd237ebb30c767">resize</a>(vcl_compressed_matrix.size1());</div>
<div class="line"><span class="keywordflow">for</span> (std::size_t i=0; i<std_result.<a name="a26"></a><a class="code" href="classviennacl_1_1vector__base.html#a15c47ae4326098aeaa4ed6b91fc6df9b">size</a>(); ++i)</div>
<div class="line"> std_result[i] = <a class="code" href="fft__1d_8cpp.html#ad5c19ca4f47d3f8ec21232a5af2624e5">ScalarType</a>(1);</div>
<div class="line"></div>
<div class="line"><span class="comment">// Copy to GPU</span></div>
<div class="line"><a class="code" href="namespaceviennacl.html#a10b7f8cf6b8864a7aa196d670481a453">viennacl::copy</a>(std_vec, vcl_vec);</div>
<div class="line"><a class="code" href="namespaceviennacl.html#a10b7f8cf6b8864a7aa196d670481a453">viennacl::copy</a>(std_result, vcl_result);</div>
<div class="line"></div>
<div class="line">vcl_vec = <a class="code" href="namespaceviennacl_1_1linalg.html#aa18d10f8a90e38bd9ff43c650fc670ef">viennacl::linalg::prod</a>(vcl_compressed_matrix, vcl_result);</div>
</div><!-- fragment --><p> Instantiate a tag for the conjugate gradient solver, the AMG preconditioner tag, and create an AMG preconditioner object: </p>
<div class="fragment"><div class="line"><a class="code" href="classviennacl_1_1linalg_1_1cg__tag.html">viennacl::linalg::cg_tag</a> cg_solver(1e-8, 10000);</div>
<div class="line"></div>
<div class="line"><a class="code" href="classviennacl_1_1context.html">viennacl::context</a> host_ctx(<a name="a27"></a><a class="code" href="namespaceviennacl.html#a00b40450b6b2fd87aad3527d9b2084b8a427356f0fb1b8d32b28f37e36b272df4">viennacl::MAIN_MEMORY</a>);</div>
<div class="line"><a class="code" href="classviennacl_1_1context.html">viennacl::context</a> target_ctx = <a name="a28"></a><a class="code" href="namespaceviennacl_1_1traits.html#a6707f5dab8f482170d2046a605f46ef8">viennacl::traits::context</a>(vcl_compressed_matrix);</div>
</div><!-- fragment --><p> Run solver without preconditioner. This serves as a baseline for comparison. Note that iterative solvers without preconditioner on GPUs can be very efficient because they map well to the massively parallel hardware. </p>
<div class="fragment"><div class="line">std::cout << <span class="stringliteral">"-- CG solver (no preconditioner, warmup) --"</span> << std::endl;</div>
<div class="line"><a class="code" href="solver_8cpp.html#afadbea4317c8f42f54d4622cf0a1829f">run_solver</a>(vcl_compressed_matrix, vcl_vec, vcl_result, cg_solver, <a name="_a29"></a><a class="code" href="classviennacl_1_1linalg_1_1no__precond.html">viennacl::linalg::no_precond</a>());</div>
</div><!-- fragment --><p> Generate the setup for an AMG preconditioner of Ruge-Stueben type with only one pass and direct interpolation (ONEPASS+DIRECT) </p>
<div class="fragment"><div class="line"><a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html">viennacl::linalg::amg_tag</a> amg_tag_direct;</div>
<div class="line">amg_tag_direct.<a name="a30"></a><a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a773dab9bf7799da8332b0fe916cc4771">set_coarsening_method</a>(<a name="a31"></a><a class="code" href="namespaceviennacl_1_1linalg.html#a3ba810acdca541a5eada4560982a645ca5167faa7286ca297508f581b26a048dc">viennacl::linalg::AMG_COARSENING_METHOD_ONEPASS</a>);</div>
<div class="line">amg_tag_direct.<a name="a32"></a><a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#ab33a64319b2dc25a9b2bc38771c7c5a4">set_interpolation_method</a>(<a name="a33"></a><a class="code" href="namespaceviennacl_1_1linalg.html#a9933216144a64dbd433ec02c95bbfdd7a48d5bb166d266affee4d526e8671bec2">viennacl::linalg::AMG_INTERPOLATION_METHOD_DIRECT</a>);</div>
<div class="line">amg_tag_direct.<a name="a34"></a><a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#ad5b5468b2991f795dabf0d2cc618a72b">set_strong_connection_threshold</a>(0.25);</div>
<div class="line">amg_tag_direct.<a name="a35"></a><a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a83d5125ff6aacce5400f7efc3e3fc4d6">set_jacobi_weight</a>(0.67);</div>
<div class="line">amg_tag_direct.<a name="a36"></a><a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a39e4042f7fb17c99c33ede3522c9361c">set_presmooth_steps</a>(1);</div>
<div class="line">amg_tag_direct.<a name="a37"></a><a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#ab00bf522866559edae47e527cb6d6c26">set_postsmooth_steps</a>(1);</div>
<div class="line">amg_tag_direct.<a name="a38"></a><a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a150f1b177671b9daef9ea0d4391c27d8">set_setup_context</a>(host_ctx); <span class="comment">// run setup on host</span></div>
<div class="line">amg_tag_direct.<a name="a39"></a><a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a7513d4c67b8878c034dfcd7f4a8f180c">set_target_context</a>(target_ctx); <span class="comment">// run solver cycles on device</span></div>
<div class="line">run_amg(cg_solver, vcl_vec, vcl_result, vcl_compressed_matrix, <span class="stringliteral">"ONEPASS COARSENING, DIRECT INTERPOLATION"</span>, amg_tag_direct);</div>
</div><!-- fragment --><p> Generate the setup for an aggregation-based AMG preconditioner with unsmoothed aggregation </p>
<div class="fragment"><div class="line"><a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html">viennacl::linalg::amg_tag</a> amg_tag_agg_pmis;</div>
<div class="line">amg_tag_agg_pmis.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a773dab9bf7799da8332b0fe916cc4771">set_coarsening_method</a>(<a name="a40"></a><a class="code" href="namespaceviennacl_1_1linalg.html#a3ba810acdca541a5eada4560982a645ca0d4c883a9aa8a8514fb260ac404e3c8b">viennacl::linalg::AMG_COARSENING_METHOD_MIS2_AGGREGATION</a>);</div>
<div class="line">amg_tag_agg_pmis.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#ab33a64319b2dc25a9b2bc38771c7c5a4">set_interpolation_method</a>(<a name="a41"></a><a class="code" href="namespaceviennacl_1_1linalg.html#a9933216144a64dbd433ec02c95bbfdd7a31dbd459c3ba8068280a6ec1bca00482">viennacl::linalg::AMG_INTERPOLATION_METHOD_AGGREGATION</a>);</div>
<div class="line">run_amg(cg_solver, vcl_vec, vcl_result, vcl_compressed_matrix, <span class="stringliteral">"AG COARSENING (PMIS), AG INTERPOLATION"</span>, amg_tag_agg_pmis);</div>
</div><!-- fragment --><p> Generate the setup for a smoothed aggregation AMG preconditioner </p>
<div class="fragment"><div class="line"><a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html">viennacl::linalg::amg_tag</a> amg_tag_sa_pmis;</div>
<div class="line">amg_tag_sa_pmis.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a773dab9bf7799da8332b0fe916cc4771">set_coarsening_method</a>(<a class="code" href="namespaceviennacl_1_1linalg.html#a3ba810acdca541a5eada4560982a645ca0d4c883a9aa8a8514fb260ac404e3c8b">viennacl::linalg::AMG_COARSENING_METHOD_MIS2_AGGREGATION</a>);</div>
<div class="line">amg_tag_sa_pmis.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#ab33a64319b2dc25a9b2bc38771c7c5a4">set_interpolation_method</a>(<a name="a42"></a><a class="code" href="namespaceviennacl_1_1linalg.html#a9933216144a64dbd433ec02c95bbfdd7afcffee5ed6e7ad032a9ffebe615b5932">viennacl::linalg::AMG_INTERPOLATION_METHOD_SMOOTHED_AGGREGATION</a>);</div>
<div class="line">run_amg (cg_solver, vcl_vec, vcl_result, vcl_compressed_matrix, <span class="stringliteral">"AG COARSENING (PMIS), SA INTERPOLATION"</span>, amg_tag_sa_pmis);</div>
<div class="line"></div>
<div class="line">std::cout << std::endl;</div>
<div class="line">std::cout << <span class="stringliteral">" -------------- Benchmark runs -------------- "</span> << std::endl;</div>
<div class="line">std::cout << std::endl;</div>
<div class="line"></div>
<div class="line">std::cout << <span class="stringliteral">"-- CG solver (no preconditioner) --"</span> << std::endl;</div>
<div class="line"><a class="code" href="solver_8cpp.html#afadbea4317c8f42f54d4622cf0a1829f">run_solver</a>(vcl_compressed_matrix, vcl_vec, vcl_result, cg_solver, <a class="code" href="classviennacl_1_1linalg_1_1no__precond.html">viennacl::linalg::no_precond</a>());</div>
<div class="line">run_amg(cg_solver, vcl_vec, vcl_result, vcl_compressed_matrix, <span class="stringliteral">"ONEPASS COARSENING, DIRECT INTERPOLATION"</span>, amg_tag_direct);</div>
<div class="line">run_amg(cg_solver, vcl_vec, vcl_result, vcl_compressed_matrix, <span class="stringliteral">"AG COARSENING (PMIS), AG INTERPOLATION"</span>, amg_tag_agg_pmis);</div>
<div class="line">run_amg (cg_solver, vcl_vec, vcl_result, vcl_compressed_matrix, <span class="stringliteral">"AG COARSENING (PMIS), SA INTERPOLATION"</span>, amg_tag_sa_pmis);</div>
</div><!-- fragment --><p> That's it. </p>
<div class="fragment"><div class="line"> std::cout << <span class="stringliteral">"!!!! TUTORIAL COMPLETED SUCCESSFULLY !!!!"</span> << std::endl;</div>
<div class="line"></div>
<div class="line"> <span class="keywordflow">return</span> EXIT_SUCCESS;</div>
<div class="line">}</div>
</div><!-- fragment --> <h2>Full Example Code</h2>
<div class="fragment"><div class="line"><span class="comment">/* =========================================================================</span></div>
<div class="line"><span class="comment"> Copyright (c) 2010-2016, Institute for Microelectronics,</span></div>
<div class="line"><span class="comment"> Institute for Analysis and Scientific Computing,</span></div>
<div class="line"><span class="comment"> TU Wien.</span></div>
<div class="line"><span class="comment"> Portions of this software are copyright by UChicago Argonne, LLC.</span></div>
<div class="line"><span class="comment"></span></div>
<div class="line"><span class="comment"> -----------------</span></div>
<div class="line"><span class="comment"> ViennaCL - The Vienna Computing Library</span></div>
<div class="line"><span class="comment"> -----------------</span></div>
<div class="line"><span class="comment"></span></div>
<div class="line"><span class="comment"> Project Head: Karl Rupp rupp@iue.tuwien.ac.at</span></div>
<div class="line"><span class="comment"></span></div>
<div class="line"><span class="comment"> (A list of authors and contributors can be found in the PDF manual)</span></div>
<div class="line"><span class="comment"></span></div>
<div class="line"><span class="comment"> License: MIT (X11), see file LICENSE in the base directory</span></div>
<div class="line"><span class="comment">============================================================================= */</span></div>
<div class="line"></div>
<div class="line"></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="vector_8hpp.html">viennacl/vector.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="coordinate__matrix_8hpp.html">viennacl/coordinate_matrix.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="compressed__matrix_8hpp.html">viennacl/compressed_matrix.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="ilu_8hpp.html">viennacl/linalg/ilu.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="cg_8hpp.html">viennacl/linalg/cg.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="bicgstab_8hpp.html">viennacl/linalg/bicgstab.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="matrix__market_8hpp.html">viennacl/io/matrix_market.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="norm__2_8hpp.html">viennacl/linalg/norm_2.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="matrix__generation_8hpp.html">viennacl/tools/matrix_generation.hpp</a>"</span></div>
<div class="line"></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="amg_8hpp.html">viennacl/linalg/amg.hpp</a>"</span></div>
<div class="line"></div>
<div class="line"><span class="preprocessor">#include <iostream></span></div>
<div class="line"><span class="preprocessor">#include <vector></span></div>
<div class="line"><span class="preprocessor">#include <ctime></span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="vector-io_8hpp.html">vector-io.hpp</a>"</span></div>
<div class="line"><span class="preprocessor">#include "<a class="code" href="timer_8hpp.html">viennacl/tools/timer.hpp</a>"</span></div>
<div class="line"></div>
<div class="line"></div>
<div class="line"><span class="keyword">template</span><<span class="keyword">typename</span> MatrixType, <span class="keyword">typename</span> VectorType, <span class="keyword">typename</span> SolverTag, <span class="keyword">typename</span> PrecondTag></div>
<div class="line"><span class="keywordtype">void</span> <a class="code" href="solver_8cpp.html#afadbea4317c8f42f54d4622cf0a1829f">run_solver</a>(MatrixType <span class="keyword">const</span> & matrix, VectorType <span class="keyword">const</span> & rhs, VectorType <span class="keyword">const</span> & ref_result, SolverTag <span class="keyword">const</span> & solver, PrecondTag <span class="keyword">const</span> & precond)</div>
<div class="line">{</div>
<div class="line"> VectorType result(rhs);</div>
<div class="line"> VectorType residual(rhs);</div>
<div class="line"></div>
<div class="line"> <a class="code" href="classviennacl_1_1tools_1_1timer.html">viennacl::tools::timer</a> timer;</div>
<div class="line"> timer.<a class="code" href="classviennacl_1_1tools_1_1timer.html#ac3e360cdcecfb05861baa2800e4f2888">start</a>();</div>
<div class="line"> result = <a class="code" href="namespaceviennacl_1_1linalg.html#a6e9b329b64ac782e6a5687ad2fc47a2a">viennacl::linalg::solve</a>(matrix, rhs, solver, precond);</div>
<div class="line"> <a class="code" href="namespaceviennacl_1_1backend.html#a3707340b27c535438e213e3879b0f0a4">viennacl::backend::finish</a>();</div>
<div class="line"> std::cout << <span class="stringliteral">" > Solver time: "</span> << timer.<a class="code" href="classviennacl_1_1tools_1_1timer.html#af44313f16c89e97704c90b1ebcc17bca">get</a>() << std::endl;</div>
<div class="line"> residual -= <a class="code" href="namespaceviennacl_1_1linalg.html#aa18d10f8a90e38bd9ff43c650fc670ef">viennacl::linalg::prod</a>(matrix, result);</div>
<div class="line"> std::cout << <span class="stringliteral">" > Relative residual: "</span> << <a class="code" href="namespaceviennacl_1_1linalg.html#ae46f15d01c01f92a153b3f555a15096b">viennacl::linalg::norm_2</a>(residual) / <a class="code" href="namespaceviennacl_1_1linalg.html#ae46f15d01c01f92a153b3f555a15096b">viennacl::linalg::norm_2</a>(rhs) << std::endl;</div>
<div class="line"> std::cout << <span class="stringliteral">" > Iterations: "</span> << solver.iters() << std::endl;</div>
<div class="line"> result -= ref_result;</div>
<div class="line"> std::cout << <span class="stringliteral">" > Relative deviation from result: "</span> << <a class="code" href="namespaceviennacl_1_1linalg.html#ae46f15d01c01f92a153b3f555a15096b">viennacl::linalg::norm_2</a>(result) / <a class="code" href="namespaceviennacl_1_1linalg.html#ae46f15d01c01f92a153b3f555a15096b">viennacl::linalg::norm_2</a>(ref_result) << std::endl;</div>
<div class="line">}</div>
<div class="line"></div>
<div class="line"><span class="keyword">template</span><<span class="keyword">typename</span> ScalarType></div>
<div class="line"><span class="keywordtype">void</span> run_amg(<a class="code" href="classviennacl_1_1linalg_1_1cg__tag.html">viennacl::linalg::cg_tag</a> & cg_solver,</div>
<div class="line"> <a class="code" href="classviennacl_1_1vector.html">viennacl::vector<ScalarType></a> & vcl_vec,</div>
<div class="line"> <a class="code" href="classviennacl_1_1vector.html">viennacl::vector<ScalarType></a> & vcl_result,</div>
<div class="line"> <a class="code" href="classviennacl_1_1compressed__matrix.html">viennacl::compressed_matrix<ScalarType></a> & vcl_compressed_matrix,</div>
<div class="line"> std::string info,</div>
<div class="line"> <a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html">viennacl::linalg::amg_tag</a> & amg_tag)</div>
<div class="line">{</div>
<div class="line"> std::cout << <span class="stringliteral">"-- CG with AMG preconditioner, "</span> << info << <span class="stringliteral">" --"</span> << std::endl;</div>
<div class="line"></div>
<div class="line"> <a class="code" href="classviennacl_1_1linalg_1_1amg__precond.html">viennacl::linalg::amg_precond<viennacl::compressed_matrix<ScalarType></a> > vcl_amg(vcl_compressed_matrix, amg_tag);</div>
<div class="line"> std::cout << <span class="stringliteral">" * Setup phase (ViennaCL types)..."</span> << std::endl;</div>
<div class="line"> <a class="code" href="classviennacl_1_1tools_1_1timer.html">viennacl::tools::timer</a> timer;</div>
<div class="line"> timer.<a class="code" href="classviennacl_1_1tools_1_1timer.html#ac3e360cdcecfb05861baa2800e4f2888">start</a>();</div>
<div class="line"> vcl_amg.setup();</div>
<div class="line"> <a class="code" href="namespaceviennacl_1_1backend.html#a3707340b27c535438e213e3879b0f0a4">viennacl::backend::finish</a>();</div>
<div class="line"> std::cout << <span class="stringliteral">" > Setup time: "</span> << timer.<a class="code" href="classviennacl_1_1tools_1_1timer.html#af44313f16c89e97704c90b1ebcc17bca">get</a>() << std::endl;</div>
<div class="line"></div>
<div class="line"> std::cout << <span class="stringliteral">" * CG solver (ViennaCL types)..."</span> << std::endl;</div>
<div class="line"> <a class="code" href="solver_8cpp.html#afadbea4317c8f42f54d4622cf0a1829f">run_solver</a>(vcl_compressed_matrix, vcl_vec, vcl_result, cg_solver, vcl_amg);</div>
<div class="line">}</div>
<div class="line"></div>
<div class="line"><span class="keywordtype">int</span> <a class="code" href="tests_2src_2bisect_8cpp.html#ae66f6b31b5ad750f1fe042a706a4e3d4">main</a>(<span class="keywordtype">int</span> argc, <span class="keywordtype">char</span> **argv)</div>
<div class="line">{</div>
<div class="line"> std::string filename(<span class="stringliteral">"../examples/testdata/mat65k.mtx"</span>);</div>
<div class="line"> <span class="keywordflow">if</span> (argc == 2)</div>
<div class="line"> filename = argv[1];</div>
<div class="line"></div>
<div class="line"> std::cout << std::endl;</div>
<div class="line"> std::cout << <span class="stringliteral">"----------------------------------------------"</span> << std::endl;</div>
<div class="line"> std::cout << <span class="stringliteral">" Device Info"</span> << std::endl;</div>
<div class="line"> std::cout << <span class="stringliteral">"----------------------------------------------"</span> << std::endl;</div>
<div class="line"></div>
<div class="line"><span class="preprocessor">#ifdef VIENNACL_WITH_OPENCL</span></div>
<div class="line"> <span class="comment">// Optional: Customize OpenCL backend</span></div>
<div class="line"> <a class="code" href="classviennacl_1_1ocl_1_1platform.html">viennacl::ocl::platform</a> pf = <a class="code" href="namespaceviennacl_1_1ocl.html#ae1e931f6efd155240b33ca440dfcfef5">viennacl::ocl::get_platforms</a>()[0];</div>
<div class="line"> std::vector<viennacl::ocl::device> <span class="keyword">const</span> & devices = pf.<a class="code" href="classviennacl_1_1ocl_1_1platform.html#afaa563522ebe9ce7b80ef02c40e7fe31">devices</a>();</div>
<div class="line"></div>
<div class="line"> <span class="comment">// Optional: Set first device to first context:</span></div>
<div class="line"> <a class="code" href="namespaceviennacl_1_1ocl.html#add1725d48cfd159ce187e287369d1cdb">viennacl::ocl::setup_context</a>(0, devices[0]);</div>
<div class="line"></div>
<div class="line"> <span class="comment">// Optional: Set second device for second context (use the same device for the second context if only one device available):</span></div>
<div class="line"> <span class="keywordflow">if</span> (devices.size() > 1)</div>
<div class="line"> <a class="code" href="namespaceviennacl_1_1ocl.html#add1725d48cfd159ce187e287369d1cdb">viennacl::ocl::setup_context</a>(1, devices[1]);</div>
<div class="line"> <span class="keywordflow">else</span></div>
<div class="line"> <a class="code" href="namespaceviennacl_1_1ocl.html#add1725d48cfd159ce187e287369d1cdb">viennacl::ocl::setup_context</a>(1, devices[0]);</div>
<div class="line"></div>
<div class="line"> std::cout << <a class="code" href="namespaceviennacl_1_1ocl.html#ac54d59a74deaccec81f64e738b856348">viennacl::ocl::current_device</a>().<a class="code" href="classviennacl_1_1ocl_1_1device.html#a26a424782f982725453808a94763bd19">info</a>() << std::endl;</div>
<div class="line"> <a class="code" href="classviennacl_1_1context.html">viennacl::context</a> ctx(<a class="code" href="namespaceviennacl_1_1ocl.html#a82c1aba632a7ee0991eee480d5340966">viennacl::ocl::get_context</a>(0));</div>
<div class="line"><span class="preprocessor">#else</span></div>
<div class="line"> <a class="code" href="classviennacl_1_1context.html">viennacl::context</a> ctx;</div>
<div class="line"><span class="preprocessor">#endif</span></div>
<div class="line"></div>
<div class="line"> <span class="keyword">typedef</span> <span class="keywordtype">double</span> <a class="code" href="fft__1d_8cpp.html#ad5c19ca4f47d3f8ec21232a5af2624e5">ScalarType</a>; <span class="comment">// feel free to change this to double if supported by your device</span></div>
<div class="line"></div>
<div class="line"></div>
<div class="line"> <a class="code" href="classviennacl_1_1compressed__matrix.html">viennacl::compressed_matrix<ScalarType></a> vcl_compressed_matrix(ctx);</div>
<div class="line"></div>
<div class="line"> <span class="comment">//viennacl::tools::generate_fdm_laplace(vcl_compressed_matrix, points_per_dim, points_per_dim);</span></div>
<div class="line"> <span class="comment">// Read matrix</span></div>
<div class="line"> std::cout << <span class="stringliteral">"Reading matrix..."</span> << std::endl;</div>
<div class="line"> std::vector< std::map<unsigned int, ScalarType> > read_in_matrix;</div>
<div class="line"> <span class="keywordflow">if</span> (!<a class="code" href="namespaceviennacl_1_1io.html#ad934125ed3dbe661e264bcd7d62b1048">viennacl::io::read_matrix_market_file</a>(read_in_matrix, filename))</div>
<div class="line"> {</div>
<div class="line"> std::cout << <span class="stringliteral">"Error reading Matrix file"</span> << std::endl;</div>
<div class="line"> <span class="keywordflow">return</span> EXIT_FAILURE;</div>
<div class="line"> }</div>
<div class="line"> <a class="code" href="namespaceviennacl.html#a10b7f8cf6b8864a7aa196d670481a453">viennacl::copy</a>(read_in_matrix, vcl_compressed_matrix);</div>
<div class="line"> std::cout << <span class="stringliteral">"Reading matrix completed."</span> << std::endl;</div>
<div class="line"></div>
<div class="line"> <a class="code" href="classviennacl_1_1vector.html">viennacl::vector<ScalarType></a> vcl_vec(vcl_compressed_matrix.<a name="a43"></a><a class="code" href="classviennacl_1_1compressed__matrix.html#a463cf1739f9cdd387aa185cb574db183">size1</a>(), ctx);</div>
<div class="line"> <a class="code" href="classviennacl_1_1vector.html">viennacl::vector<ScalarType></a> vcl_result(vcl_compressed_matrix.<a class="code" href="classviennacl_1_1compressed__matrix.html#a463cf1739f9cdd387aa185cb574db183">size1</a>(), ctx);</div>
<div class="line"></div>
<div class="line"> std::vector<ScalarType> std_vec, std_result;</div>
<div class="line"></div>
<div class="line"></div>
<div class="line"> <span class="comment">// rhs and result vector:</span></div>
<div class="line"> std_vec.<a class="code" href="classviennacl_1_1vector.html#a1b73aadf0c7b6c0028fd237ebb30c767">resize</a>(vcl_compressed_matrix.<a class="code" href="classviennacl_1_1compressed__matrix.html#a463cf1739f9cdd387aa185cb574db183">size1</a>());</div>
<div class="line"> std_result.<a class="code" href="classviennacl_1_1vector.html#a1b73aadf0c7b6c0028fd237ebb30c767">resize</a>(vcl_compressed_matrix.<a class="code" href="classviennacl_1_1compressed__matrix.html#a463cf1739f9cdd387aa185cb574db183">size1</a>());</div>
<div class="line"> <span class="keywordflow">for</span> (std::size_t i=0; i<std_result.<a class="code" href="classviennacl_1_1vector__base.html#a15c47ae4326098aeaa4ed6b91fc6df9b">size</a>(); ++i)</div>
<div class="line"> std_result[i] = <a class="code" href="fft__1d_8cpp.html#ad5c19ca4f47d3f8ec21232a5af2624e5">ScalarType</a>(1);</div>
<div class="line"></div>
<div class="line"> <span class="comment">// Copy to GPU</span></div>
<div class="line"> <a class="code" href="namespaceviennacl.html#a10b7f8cf6b8864a7aa196d670481a453">viennacl::copy</a>(std_vec, vcl_vec);</div>
<div class="line"> <a class="code" href="namespaceviennacl.html#a10b7f8cf6b8864a7aa196d670481a453">viennacl::copy</a>(std_result, vcl_result);</div>
<div class="line"></div>
<div class="line"> vcl_vec = <a class="code" href="namespaceviennacl_1_1linalg.html#aa18d10f8a90e38bd9ff43c650fc670ef">viennacl::linalg::prod</a>(vcl_compressed_matrix, vcl_result);</div>
<div class="line"></div>
<div class="line"></div>
<div class="line"> <a class="code" href="classviennacl_1_1linalg_1_1cg__tag.html">viennacl::linalg::cg_tag</a> cg_solver(1e-8, 10000);</div>
<div class="line"></div>
<div class="line"> <a class="code" href="classviennacl_1_1context.html">viennacl::context</a> host_ctx(<a class="code" href="namespaceviennacl.html#a00b40450b6b2fd87aad3527d9b2084b8a427356f0fb1b8d32b28f37e36b272df4">viennacl::MAIN_MEMORY</a>);</div>
<div class="line"> <a class="code" href="classviennacl_1_1context.html">viennacl::context</a> target_ctx = <a class="code" href="namespaceviennacl_1_1traits.html#a6707f5dab8f482170d2046a605f46ef8">viennacl::traits::context</a>(vcl_compressed_matrix);</div>
<div class="line"></div>
<div class="line"> std::cout << <span class="stringliteral">"-- CG solver (no preconditioner, warmup) --"</span> << std::endl;</div>
<div class="line"> <a class="code" href="solver_8cpp.html#afadbea4317c8f42f54d4622cf0a1829f">run_solver</a>(vcl_compressed_matrix, vcl_vec, vcl_result, cg_solver, <a class="code" href="classviennacl_1_1linalg_1_1no__precond.html">viennacl::linalg::no_precond</a>());</div>
<div class="line"></div>
<div class="line"> <a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html">viennacl::linalg::amg_tag</a> amg_tag_direct;</div>
<div class="line"> amg_tag_direct.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a773dab9bf7799da8332b0fe916cc4771">set_coarsening_method</a>(<a class="code" href="namespaceviennacl_1_1linalg.html#a3ba810acdca541a5eada4560982a645ca5167faa7286ca297508f581b26a048dc">viennacl::linalg::AMG_COARSENING_METHOD_ONEPASS</a>);</div>
<div class="line"> amg_tag_direct.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#ab33a64319b2dc25a9b2bc38771c7c5a4">set_interpolation_method</a>(<a class="code" href="namespaceviennacl_1_1linalg.html#a9933216144a64dbd433ec02c95bbfdd7a48d5bb166d266affee4d526e8671bec2">viennacl::linalg::AMG_INTERPOLATION_METHOD_DIRECT</a>);</div>
<div class="line"> amg_tag_direct.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#ad5b5468b2991f795dabf0d2cc618a72b">set_strong_connection_threshold</a>(0.25);</div>
<div class="line"> amg_tag_direct.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a83d5125ff6aacce5400f7efc3e3fc4d6">set_jacobi_weight</a>(0.67);</div>
<div class="line"> amg_tag_direct.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a39e4042f7fb17c99c33ede3522c9361c">set_presmooth_steps</a>(1);</div>
<div class="line"> amg_tag_direct.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#ab00bf522866559edae47e527cb6d6c26">set_postsmooth_steps</a>(1);</div>
<div class="line"> amg_tag_direct.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a150f1b177671b9daef9ea0d4391c27d8">set_setup_context</a>(host_ctx); <span class="comment">// run setup on host</span></div>
<div class="line"> amg_tag_direct.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a7513d4c67b8878c034dfcd7f4a8f180c">set_target_context</a>(target_ctx); <span class="comment">// run solver cycles on device</span></div>
<div class="line"> run_amg(cg_solver, vcl_vec, vcl_result, vcl_compressed_matrix, <span class="stringliteral">"ONEPASS COARSENING, DIRECT INTERPOLATION"</span>, amg_tag_direct);</div>
<div class="line"></div>
<div class="line"> <a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html">viennacl::linalg::amg_tag</a> amg_tag_agg_pmis;</div>
<div class="line"> amg_tag_agg_pmis.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a773dab9bf7799da8332b0fe916cc4771">set_coarsening_method</a>(<a class="code" href="namespaceviennacl_1_1linalg.html#a3ba810acdca541a5eada4560982a645ca0d4c883a9aa8a8514fb260ac404e3c8b">viennacl::linalg::AMG_COARSENING_METHOD_MIS2_AGGREGATION</a>);</div>
<div class="line"> amg_tag_agg_pmis.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#ab33a64319b2dc25a9b2bc38771c7c5a4">set_interpolation_method</a>(<a class="code" href="namespaceviennacl_1_1linalg.html#a9933216144a64dbd433ec02c95bbfdd7a31dbd459c3ba8068280a6ec1bca00482">viennacl::linalg::AMG_INTERPOLATION_METHOD_AGGREGATION</a>);</div>
<div class="line"> run_amg(cg_solver, vcl_vec, vcl_result, vcl_compressed_matrix, <span class="stringliteral">"AG COARSENING (PMIS), AG INTERPOLATION"</span>, amg_tag_agg_pmis);</div>
<div class="line"></div>
<div class="line"> <a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html">viennacl::linalg::amg_tag</a> amg_tag_sa_pmis;</div>
<div class="line"> amg_tag_sa_pmis.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#a773dab9bf7799da8332b0fe916cc4771">set_coarsening_method</a>(<a class="code" href="namespaceviennacl_1_1linalg.html#a3ba810acdca541a5eada4560982a645ca0d4c883a9aa8a8514fb260ac404e3c8b">viennacl::linalg::AMG_COARSENING_METHOD_MIS2_AGGREGATION</a>);</div>
<div class="line"> amg_tag_sa_pmis.<a class="code" href="classviennacl_1_1linalg_1_1amg__tag.html#ab33a64319b2dc25a9b2bc38771c7c5a4">set_interpolation_method</a>(<a class="code" href="namespaceviennacl_1_1linalg.html#a9933216144a64dbd433ec02c95bbfdd7afcffee5ed6e7ad032a9ffebe615b5932">viennacl::linalg::AMG_INTERPOLATION_METHOD_SMOOTHED_AGGREGATION</a>);</div>
<div class="line"> run_amg (cg_solver, vcl_vec, vcl_result, vcl_compressed_matrix, <span class="stringliteral">"AG COARSENING (PMIS), SA INTERPOLATION"</span>, amg_tag_sa_pmis);</div>
<div class="line"></div>
<div class="line"> std::cout << std::endl;</div>
<div class="line"> std::cout << <span class="stringliteral">" -------------- Benchmark runs -------------- "</span> << std::endl;</div>
<div class="line"> std::cout << std::endl;</div>
<div class="line"></div>
<div class="line"> std::cout << <span class="stringliteral">"-- CG solver (no preconditioner) --"</span> << std::endl;</div>
<div class="line"> <a class="code" href="solver_8cpp.html#afadbea4317c8f42f54d4622cf0a1829f">run_solver</a>(vcl_compressed_matrix, vcl_vec, vcl_result, cg_solver, <a class="code" href="classviennacl_1_1linalg_1_1no__precond.html">viennacl::linalg::no_precond</a>());</div>
<div class="line"> run_amg(cg_solver, vcl_vec, vcl_result, vcl_compressed_matrix, <span class="stringliteral">"ONEPASS COARSENING, DIRECT INTERPOLATION"</span>, amg_tag_direct);</div>
<div class="line"> run_amg(cg_solver, vcl_vec, vcl_result, vcl_compressed_matrix, <span class="stringliteral">"AG COARSENING (PMIS), AG INTERPOLATION"</span>, amg_tag_agg_pmis);</div>
<div class="line"> run_amg (cg_solver, vcl_vec, vcl_result, vcl_compressed_matrix, <span class="stringliteral">"AG COARSENING (PMIS), SA INTERPOLATION"</span>, amg_tag_sa_pmis);</div>
<div class="line"></div>
<div class="line"> std::cout << <span class="stringliteral">"!!!! TUTORIAL COMPLETED SUCCESSFULLY !!!!"</span> << std::endl;</div>
<div class="line"></div>
<div class="line"> <span class="keywordflow">return</span> EXIT_SUCCESS;</div>
<div class="line">}</div>
<div class="line"></div>
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