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Checked Matrix::collect() with different timing metric, and memcpy has approx 25% speedup over original version. Matrix_range is slower or the same speed as the original version.

release/4.3a0
Alex Cunningham 2010-01-20 13:45:22 +00:00
parent 977a97eacf
commit 6bc0462669
2 changed files with 19 additions and 2 deletions
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10
cpp/Matrix.cpp
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@ -506,6 +506,16 @@ Matrix collect(const std::vector<const Matrix *>& matrices, size_t m, size_t n)
dimA2 += M->size2();
}
// original version
// Matrix A(dimA1, dimA2);
// size_t hindex = 0;
// BOOST_FOREACH(const Matrix* M, matrices) {
// for(size_t d1 = 0; d1 < M->size1(); d1++)
// for(size_t d2 = 0; d2 < M->size2(); d2++)
// A(d1, d2+hindex) = (*M)(d1, d2);
// hindex += M->size2();
// }
// matrix_range version
// Result: slower
// Matrix A(dimA1, dimA2);

11
cpp/timeMatrix.cpp
View File

@ -14,9 +14,14 @@ using namespace gtsam;
/*
* Results:
* Alex's Machine:
* (using p = 100000 m = 10 n = 12 reps = 50) - Average times
* - (1st pass of simple changes) no pass: 0.184 sec , pass: 0.181 sec
* - (1st rev memcpy) no pass: 0.181 sec , pass: 0.180 sec
* - (1st rev matrix_range) no pass: 0.186 sec , pass: 0.184 sec
* (using p = 10 m = 10 n = 12 reps = 10000000)
* - (matrix_range version) no pass: 24.21 sec , pass: 23.97 sec
* - (memcpy version) no pass: 18.96 sec , pass: 18.39 sec
* - (original version) no pass: 23.45 sec , pass: 22.80 sec
*/
double timeCollect(size_t p, size_t m, size_t n, bool passDims, size_t reps) {
// create a large number of matrices
@ -52,7 +57,8 @@ double timeCollect(size_t p, size_t m, size_t n, bool passDims, size_t reps) {
delete matrices[i];
}
return elapsed/reps;
return elapsed;
//return elapsed/reps;
}
/*
@ -119,7 +125,8 @@ int main(int argc, char ** argv) {
// Time collect()
cout << "Starting Matrix::collect() Timing" << endl;
size_t p = 100000; size_t m = 10; size_t n = 12; size_t reps = 50;
//size_t p = 100000; size_t m = 10; size_t n = 12; size_t reps = 50;
size_t p = 10; size_t m = 10; size_t n = 12; size_t reps = 10000000;
double collect_time1 = timeCollect(p, m, n, false, reps);
double collect_time2 = timeCollect(p, m, n, true, reps);
cout << "Average Elapsed time for collect (no pass) [" << p << " (" << m << ", " << n << ") matrices] : " << collect_time1 << endl;