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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
commit | cca66b9ec4e494c1d919bff0f71a820d8afab1fa (patch) | |
tree | 146f39ded1c938019e1ed42d30923c2ac9e86789 /src/3rdparty/2geom/tests/root-find-test.cpp | |
parent | Initial commit. (diff) | |
download | inkscape-upstream.tar.xz inkscape-upstream.zip |
Adding upstream version 1.2.2.upstream/1.2.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/3rdparty/2geom/tests/root-find-test.cpp')
-rw-r--r-- | src/3rdparty/2geom/tests/root-find-test.cpp | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/src/3rdparty/2geom/tests/root-find-test.cpp b/src/3rdparty/2geom/tests/root-find-test.cpp new file mode 100644 index 0000000..b866f66 --- /dev/null +++ b/src/3rdparty/2geom/tests/root-find-test.cpp @@ -0,0 +1,156 @@ +#include <2geom/polynomial.h> +#include <vector> +#include <iterator> + +#include <2geom/sbasis.h> +#include <2geom/sbasis-poly.h> +#include <2geom/sbasis-to-bezier.h> +#include <2geom/solver.h> +#include <time.h> + +using namespace std; +using namespace Geom; + +Poly lin_poly(double a, double b) { // ax + b + Poly p; + p.push_back(b); + p.push_back(a); + return p; +} + +Linear linear(double ax, double b) { + return Linear(b, ax+b); +} + +double uniform() { + return double(rand()) / RAND_MAX; +} + +int main() { + Poly a, b, r; + double timer_precision = 0.01; + double units = 1e6; // us + + a = Poly::linear(1, -0.3)*Poly::linear(1, -0.25)*Poly::linear(1, -0.2); + + std::cout << a <<std::endl; + SBasis B = poly_to_sbasis(a); + std::cout << B << std::endl; + Bezier bez; + sbasis_to_bezier(bez, B); + cout << bez << endl; + //copy(bez.begin(), bez.end(), ostream_iterator<double>(cout, ", ")); + cout << endl; + cout << endl; + cout << endl; + + std::vector<std::vector<double> > trials; + + // evenly spaced roots + for(int N = 2; N <= 5; N++) + { + std::vector<double> r; + for(int i = 0; i < N; i++) + r.push_back(double(i)/(N-1)); + trials.push_back(r); + } + // sort of evenish + for(int N = 0; N <= 5; N++) + { + std::vector<double> r; + for(int i = 0; i < N; i++) + r.push_back(double(i+0.5)/(2*N)); + trials.push_back(r); + } + // one at 0.1 + for(int N = 0; N <= 5; N++) + { + std::vector<double> r; + for(int i = 0; i < N; i++) + r.push_back(i+0.1); + trials.push_back(r); + } + for(int N = 0; N <= 6; N++) + { + std::vector<double> r; + for(int i = 0; i < N; i++) + r.push_back(i*0.8+0.1); + trials.push_back(r); + } + for(int N = 0; N <= 20; N++) + { + std::vector<double> r; + for(int i = 0; i < N/2; i++) { + r.push_back(0.1); + r.push_back(0.9); + } + trials.push_back(r); + } + for(int i = 0; i <= 20; i++) + { + std::vector<double> r; + for(int i = 0; i < 4; i++) { + r.push_back(uniform()*5 - 2.5); + r.push_back(0.9); + } + trials.push_back(r); + } + double ave_left = 0; + cout << "err from exact\n"; + for(auto & trial : trials) { + SBasis B = Linear(1.,1); + sort(trial.begin(), trial.end()); + for(double j : trial) { + B = B*linear(1, -j); + } + double left_time; + clock_t end_t = clock()+clock_t(timer_precision*CLOCKS_PER_SEC); + unsigned iterations = 0; + while(end_t > clock()) { + roots(B); + iterations++; + } + left_time = timer_precision*units/iterations; + vector<double> rt = roots(B); + double err = 0; + for(double r : rt) { + double best = fabs(r - trial[0]); + for(unsigned j = 1; j < trial.size(); j++) { + if(fabs(r - trial[j]) < best) + best = fabs(r - trial[j]); + } + err += best; + } + if(err > 1e-8){ + for(double j : trial) { + cout << j << ", "; + } + cout << endl; + } + cout << " e: " << err << std::endl; + ave_left += left_time; + } + cout << "average time = " << ave_left/trials.size() << std::endl; + + for(int i = 10; i >= 0; i--) { + vector<double> rt = roots(Linear(i,-1)); + for(double j : rt) { + cout << j << ", "; + } + cout << endl; + } + + return 0; +} + + +/* + Local Variables: + mode:c++ + c-file-style:"stroustrup" + c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +)) + indent-tabs-mode:nil + fill-column:99 + End: +*/ +// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 : |