diff options
author | Colin Fletcher <colin.m.fletcher@googlemail.com> | 2015-02-13 12:25:26 +0000 |
---|---|---|
committer | Colin Fletcher <colin.m.fletcher@googlemail.com> | 2015-02-13 12:25:51 +0000 |
commit | cb3961d9534d3bd86cc2c1c2be72b8eb33717e77 (patch) | |
tree | e0f79edfa92144d09b0d59f92fd74ee7bd10be3c /libs/evoral/test | |
parent | 5ec93d18e16f83ff4548ea27379c813c8f42e413 (diff) |
Add a test for the constrained cubic interpolation of Evoral::Curve
Add a test, based on the worked example in www.korf.co.uk/spline.pdf, for
the constrained cubic spline interpolation.
The delta values for the float comparisons are rather arbitrary, I'm sorry
to say: they're basically chosen so that everything passes.
Diffstat (limited to 'libs/evoral/test')
-rw-r--r-- | libs/evoral/test/CurveTest.cpp | 180 | ||||
-rw-r--r-- | libs/evoral/test/CurveTest.hpp | 2 |
2 files changed, 182 insertions, 0 deletions
diff --git a/libs/evoral/test/CurveTest.cpp b/libs/evoral/test/CurveTest.cpp index 36c4d808d2..32c6fa2d64 100644 --- a/libs/evoral/test/CurveTest.cpp +++ b/libs/evoral/test/CurveTest.cpp @@ -227,3 +227,183 @@ CurveTest::ctrlListEval () CPPUNIT_ASSERT_EQUAL(8.5, cl->unlocked_eval(350.)); CPPUNIT_ASSERT_EQUAL(9.0, cl->unlocked_eval(999.)); } + +void +CurveTest::constrainedCubic () +{ + + struct point { + int x, y; + }; + + static const struct point data[] = { + /* values from worked example in www.korf.co.uk/spline.pdf */ + { 0, 30 }, + { 10, 130 }, + { 30, 150 }, + { 50, 150 }, + { 70, 170 }, + { 90, 220 }, + { 100, 320 }, + }; + + int32_t type = 0; + Evoral::Parameter p(type); + Evoral::ParameterDescriptor pd; + Evoral::ControlList l(p,pd); + + size_t i; + l.set_interpolation(Evoral::ControlList::Curved); + + for (i=0; i<sizeof(data)/sizeof(data[0]); i++) { + l.add (data[i].x, data[i].y); + } + + Evoral::Curve curve(l); + + float f[121]; + curve.get_vector(-10, 110, f, 121); + + const float *g = &f[10]; /* so g starts at x==0 */ + + /* given points - should be exactly equal */ + CPPUNIT_ASSERT_EQUAL( 30.0f, g[-10]); + CPPUNIT_ASSERT_EQUAL( 30.0f, g[ 0]); + CPPUNIT_ASSERT_EQUAL(130.0f, g[ 10]); + CPPUNIT_ASSERT_EQUAL(150.0f, g[ 30]); + CPPUNIT_ASSERT_EQUAL(150.0f, g[ 40]); + CPPUNIT_ASSERT_EQUAL(150.0f, g[ 50]); + CPPUNIT_ASSERT_EQUAL(320.0f, g[100]); + CPPUNIT_ASSERT_EQUAL(320.0f, g[110]); + + /* + First segment, i=1, for 0 <= x <= 10 + f'1(x1) = 2/((x2 – x1)/(y2 – y1) + (x1 – x0)/(y1 – y0)) + = 2/((30 – 10)/(150 – 130) + (10 – 0)/(130 – 30)) + = 1.8181 + f'1(x0) = 3/2*(y1 – y0)/(x1 – x0) - f'1(x1)/2 + = 3/2*(130 – 30)/(10 – 0) – 1.818/2 + = 14.0909 + f"1(x0) = -2*(f'1(x1) + 2* f'1(x0))/(x1 – x0) + 6*(y1 – y0)/ (x1 – x0)^2 + = -2*(1.8181 + 2*14.0909)/(10 – 0) + 6*(130 – 30)/(10 – 0)^2 + = 0 + f"1(x1) = 2*(2*f'1(x1) + f'1(x0))/(x1 – x0) - 6*(y1 – y0)/ (x1 – x0)^2 + = 2*(2*1.818 + 14.0909)/(10 – 0) – 6*(130 – 30)/(10 – 0)^2 + = -2.4545 + d1 = 1/6 * (f"1(x1) - f"1(x0))/(x1 – x0) + = 1/6 * (-2.4545 – 0)/(10 – 0) + = -0.0409 + c1 = 1/2 * (x1*f"1(x0) – x0*f"1(x1))/(x1 – x0) + = 1/2 * (10*0 – 0*1.8181)/(10 – 0) + = 0 + b1 = ((y1 – y0) – c1*(x21 – x20) – d1*( x31 – x30))/(x1 – x0) + = ((130 – 30) – 0*(102 – 02) + 0.0409*(103 – 03))/(10 – 0) + = 14.09 + a1 = y0 – b1*x0 – c1*x20 – d1*x30 + = 30 + y1 = 30 + 14.09x - 0.0409x3 for 0 <= x <= 10 + */ + /* + Second segment, i=2, for 10 <= x <= 30 + f'2(x2) = 2/((x3 – x2)/(y3 – y2) + (x2 – x1)/(y2 – y1)) + = 2/((50 – 30)/(150 – 150) + (30 – 10)/(150 – 130)) + = 0 + f'2(x1) = 2/((x2 – x1)/(y2 – y1) + (x1 – x0)/(y1 – y0)) + = 1.8181 + + f"2(x1) = -2*(f'2(x2) + 2* f'2(x1))/(x2 – x1) + 6*(y2 – y1)/ (x2 – x1)^2 + = -2*(0 + 2*1.8181)/(30 – 10) + 6*(150 – 130)/(30 – 10)2 + = -0.063636 + f"2(x2) = 2*(2*f'2(x2) + f'2(x1))/(x2 – x1) - 6*(y2 – y1)/ (x2 – x1)^2 + = 2*(2*0 + 1.8181)/(30 – 10) – 6*(150 – 130)/(30 – 10)^2 + = -0.11818 + + d2 = 1/6 * (f"2(x2) - f"2(x1))/(x2 – x1) + = 1/6 * (-0.11818 + 0.063636)/(30 – 10) + = -0.0004545 + c2 = 1/2 * (x2*f"2(x1) – x1*f"2(x2))/(x2 – x1) + = 1/2 * (-30*0.063636 + 10*0.11818)/(30 – 10) + = -0.01818 + b2 = ((y2 – y1) – c2*(x2^2 – x1^2) – d2*( x2^3 – x1^3))/(x2 – x1) + = ((150 – 130) + 0.01818*(302 – 102) + 0.0004545*(303 – 103))/(30 – 10) + = 2.31818 + a2 = y1 – b2*x1 – c2*x1^2 – d2*x1^3 + = 130 – 2.31818*10 + 0.01818*102 + 0.0004545*103 + = 109.09 + y2 = 109.09 + 2.31818x - 0.01818x^2 - 0.0004545x^3 for 10 <= x <= 30 + */ + + + int x; + long double a1, b1, c1, d1, a2, b2, c2, d2, fdx0, fddx0, fdx1, fdx2, fddx1, fddx2; + double x0 = data[0].x; + double y0 = data[0].y; + double x1 = data[1].x; + double y1 = data[1].y; + double x2 = data[2].x; + double y2 = data[2].y; + double x3 = data[3].x; + double y3 = data[3].y; + + double dx0 = x1 - x0; + double dy0 = y1 - y0; + double dx1 = x2 - x1; + double dy1 = y2 - y1; + double dx2 = x3 - x2; + double dy2 = y3 - y2; + + // First (leftmost) segment + fdx1 = 2.0 / ( dx1 / dy1 + dx0 / dy0 ); + fdx0 = 3.0 / 2.0 * dy0 / dx0 - fdx1 / 2.0; + + fddx0 = -2.0 * (fdx1 + 2.0 * fdx0) / dx0 + 6.0 * dy0 / (dx0*dx0); + fddx1 = 2.0 * (2.0 * fdx1 + fdx0) / dx0 - 6.0 * dy0 / (dx0*dx0); + d1 = 1.0 / 6.0 * (fddx1 - fddx0) / dx0; + c1 = 1.0 / 2.0 * (x1 * fddx0 - x0 * fddx1) / dx0; + b1 = (dy0 - c1 * (x1* x1 - x0*x0) - d1 * (x1*x1*x1 - x0*x0*x0)) / dx0; + a1 = y0 - b1*x0 - c1*x0*x0 - d1*x0*x0*x0; + + // printf("dx0=%f, dy0=%f, dx1=%f, dy1=%f\n", dx0, dy0, dx1, dy1); + // printf("fdx0=%Lf, fdx1=%Lf, fddx0=%Lf, fddx1=%Lf\n", fdx0, fdx1, fddx0, fddx1); + // printf("a1=%Lf, b1=%Lf, c1=%Lf, d1=%Lf\n", a1, b1, c1, d1); + + // values from worked example: deltas rather arbitrary, I'm afraid + CPPUNIT_ASSERT_DOUBLES_EQUAL(30.0, a1, 0); + CPPUNIT_ASSERT_DOUBLES_EQUAL(14.09, b1, 0.001); + CPPUNIT_ASSERT_DOUBLES_EQUAL(0.0, c1, 0); + CPPUNIT_ASSERT_DOUBLES_EQUAL(-0.0409, d1, 0.00001); + + for (x = 0; x <= 10; x++) { + double v = a1 + b1*x + c1*x*x + d1*x*x*x; + char msg[64]; + snprintf(msg, 64, "interpolating %d: v=%f, x=%f...\n", x, v, g[x]); + CPPUNIT_ASSERT_DOUBLES_EQUAL(v, g[x], 0.000004); + } + + // Second segment + fdx2 = 2.0 / ( dx2 / dy2 + dx1 / dy1 ); + + fddx1 = -2.0 * (fdx2 + 2.0 * fdx1) / dx1 + 6.0 * dy1 / (dx1*dx1); + fddx2 = 2.0 * (2.0 * fdx2 + fdx1) / dx1 - 6.0 * dy1 / (dx1*dx1); + d2 = 1.0 / 6.0 * (fddx2 - fddx1) / dx1; + c2 = 1.0 / 2.0 * (x2 * fddx1 - x1 * fddx2) / dx1; + b2 = (dy1 - c2 * (x2*x2 - x1*x1) - d2 * (x2*x2*x2 - x1*x1*x1)) / dx1; + a2 = y1 - b2*x1 - c2*x1*x1 - d2*x1*x1*x1; + + // printf("dx0=%f, dy0=%f, dx1=%f, dy1=%f dx2=%f, dy2=%f\n", dx0, dy0, dx1, dy1, dx2, dy2); + // printf("fdx1=%Lf, fdx2=%Lf, fddx1=%Lf, fddx2=%Lf\n", fdx1, fdx2, fddx1, fddx2); + // printf("a2=%Lf, b2=%Lf, c2=%Lf, d2=%Lf\n", a2, b2, c2, d2); + + // values from worked example: deltas rather arbitrary, I'm afraid + CPPUNIT_ASSERT_DOUBLES_EQUAL(109.09, a2, 0.001); + CPPUNIT_ASSERT_DOUBLES_EQUAL(2.31818, b2, 0.00001); + CPPUNIT_ASSERT_DOUBLES_EQUAL(-0.01818, c2, 0.00001); + CPPUNIT_ASSERT_DOUBLES_EQUAL(-0.0004545, d2, 0.0000001); + + for (x = 10; x <= 30; x++) { + double v = a2 + b2*x + c2*x*x + d2*x*x*x; + char msg[64]; + snprintf(msg, 64, "interpolating %d: v=%f, x=%f...\n", x, v, g[x]); + CPPUNIT_ASSERT_DOUBLES_EQUAL(v, g[x], 0.000008); + } +} diff --git a/libs/evoral/test/CurveTest.hpp b/libs/evoral/test/CurveTest.hpp index a1c37d4246..9867edc8c6 100644 --- a/libs/evoral/test/CurveTest.hpp +++ b/libs/evoral/test/CurveTest.hpp @@ -9,6 +9,7 @@ class CurveTest : public CppUnit::TestFixture CPPUNIT_TEST (twoPointLinear); CPPUNIT_TEST (threePointLinear); CPPUNIT_TEST (threePointDiscete); + CPPUNIT_TEST (constrainedCubic); CPPUNIT_TEST (ctrlListEval); CPPUNIT_TEST_SUITE_END (); @@ -16,6 +17,7 @@ public: void twoPointLinear (); void threePointLinear (); void threePointDiscete (); + void constrainedCubic (); void ctrlListEval (); private: |