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Diffstat (limited to 'src/boost/libs/compute/example/batched_determinant.cpp')
-rw-r--r-- | src/boost/libs/compute/example/batched_determinant.cpp | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/src/boost/libs/compute/example/batched_determinant.cpp b/src/boost/libs/compute/example/batched_determinant.cpp new file mode 100644 index 00000000..0029151e --- /dev/null +++ b/src/boost/libs/compute/example/batched_determinant.cpp @@ -0,0 +1,96 @@ +//---------------------------------------------------------------------------// +// Copyright (c) 2013-2014 Kyle Lutz <kyle.r.lutz@gmail.com> +// +// Distributed under the Boost Software License, Version 1.0 +// See accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt +// +// See http://boostorg.github.com/compute for more information. +//---------------------------------------------------------------------------// + +#include <iostream> + +#include <Eigen/Core> +#include <Eigen/LU> + +#include <boost/compute/function.hpp> +#include <boost/compute/system.hpp> +#include <boost/compute/algorithm/transform.hpp> +#include <boost/compute/container/vector.hpp> +#include <boost/compute/types/fundamental.hpp> + +namespace compute = boost::compute; + +// this example shows how to compute the determinant of many 4x4 matrices +// using a determinant function and the transform() algorithm. in OpenCL the +// float16 type can be used to store a 4x4 matrix and the components are laid +// out in the following order: +// +// M = [ s0 s4 s8 sc ] +// [ s1 s5 s9 sd ] +// [ s2 s6 sa se ] +// [ s3 s7 sb sf ] +// +// the input matrices are created using eigen's random matrix and then +// used again at the end to verify the results of the determinant function. +int main() +{ + // get default device and setup context + compute::device gpu = compute::system::default_device(); + compute::context context(gpu); + compute::command_queue queue(context, gpu); + std::cout << "device: " << gpu.name() << std::endl; + + size_t n = 1000; + + // create random 4x4 matrices on the host + std::vector<Eigen::Matrix4f> matrices(n); + for(size_t i = 0; i < n; i++){ + matrices[i] = Eigen::Matrix4f::Random(); + } + + // copy matrices to the device + using compute::float16_; + compute::vector<float16_> input(n, context); + compute::copy( + matrices.begin(), matrices.end(), input.begin(), queue + ); + + // function returning the determinant of a 4x4 matrix. + BOOST_COMPUTE_FUNCTION(float, determinant4x4, (const float16_ m), + { + return m.s0*m.s5*m.sa*m.sf + m.s0*m.s6*m.sb*m.sd + m.s0*m.s7*m.s9*m.se + + m.s1*m.s4*m.sb*m.se + m.s1*m.s6*m.s8*m.sf + m.s1*m.s7*m.sa*m.sc + + m.s2*m.s4*m.s9*m.sf + m.s2*m.s5*m.sb*m.sc + m.s2*m.s7*m.s8*m.sd + + m.s3*m.s4*m.sa*m.sd + m.s3*m.s5*m.s8*m.se + m.s3*m.s6*m.s9*m.sc - + m.s0*m.s5*m.sb*m.se - m.s0*m.s6*m.s9*m.sf - m.s0*m.s7*m.sa*m.sd - + m.s1*m.s4*m.sa*m.sf - m.s1*m.s6*m.sb*m.sc - m.s1*m.s7*m.s8*m.se - + m.s2*m.s4*m.sb*m.sd - m.s2*m.s5*m.s8*m.sf - m.s2*m.s7*m.s9*m.sc - + m.s3*m.s4*m.s9*m.se - m.s3*m.s5*m.sa*m.sc - m.s3*m.s6*m.s8*m.sd; + }); + + // calculate determinants on the gpu + compute::vector<float> determinants(n, context); + compute::transform( + input.begin(), input.end(), determinants.begin(), determinant4x4, queue + ); + + // check determinants + std::vector<float> host_determinants(n); + compute::copy( + determinants.begin(), determinants.end(), host_determinants.begin(), queue + ); + + for(size_t i = 0; i < n; i++){ + float det = matrices[i].determinant(); + + if(std::abs(det - host_determinants[i]) > 1e-6){ + std::cerr << "error: wrong determinant at " << i << " (" + << host_determinants[i] << " != " << det << ")" + << std::endl; + return -1; + } + } + + return 0; +} |