maspack.geometry

Class QuadraticUtilsTest

java.lang.Object

maspack.util.UnitTest

maspack.geometry.QuadraticUtilsTest

public class QuadraticUtilsTest
extends UnitTest

Utility methods for quadratic shapes and surfaces.

Constructor Summary

Constructors

Constructor and Description
QuadraticUtilsTest()

Method Summary

Modifier and Type	Method and Description
double	clipDratio(double a, double b, double dratio)
static double	ellipsoidPenetrationDistanceOmar(Vector3d nrm, Vector3d pos, Vector3d p0, double a, double b, double c, double tol, IntHolder numIters, boolean debug) Alternative implementation of ellipsoidPenetrationDistance() written by Omar Zarifi.
static void	main(java.lang.String[] args)
void	sphereSurfaceTangent(Point3d pr, Point3d p0, Point3d p1, double r)
void	test()
void	testEllipseDist(double a, double b, double theta, double dratio) Test nearestPointEllipse() for an ellipse with minor axis lengths a and b.
void	testEllipseDist(double a, double b, double p0x, double p0y, double pnx, double pny)
void	testEllipseDistance() Test nearestPointEllipse()
void	testEllipsoidDist(double a, double b, double c, double theta, double phi, double dratio) Test nearestPointEllipsoid() for an ellipsoid with minor axis lengths a, b, and c.
void	testEllipsoidDistance() Test nearestPointEllipsoid()
void	testEllipsoidPenetrationDistance(boolean printInfo)
void	testEllipsoidSurfaceTangent()
void	timeEllipsoidEberly(double a, double b, double c, int numtests)
void	timeEllipsoidLloyd(double a, double b, double c, int numtests)

Methods inherited from class maspack.util.UnitTest

check, checkEquals, checkEquals, checkEquals, checkEquals, checkEquals, checkEquals, checkEquals, checkEquals, checkNormedEquals, checkNormedEquals, getSilent, printUsageAndExit, runtest, setSilent

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

QuadraticUtilsTest

public QuadraticUtilsTest()

Method Detail

ellipsoidPenetrationDistanceOmar

public static double ellipsoidPenetrationDistanceOmar(Vector3d nrm,
                                                      Vector3d pos,
                                                      Vector3d p0,
                                                      double a,
                                                      double b,
                                                      double c,
                                                      double tol,
                                                      IntHolder numIters,
                                                      boolean debug)

Alternative implementation of ellipsoidPenetrationDistance() written by Omar Zarifi. Uses Newton iteration. Fasters, but can fail to converge and also can confuse maximums with minimums.

sphereSurfaceTangent

public void sphereSurfaceTangent(Point3d pr,
                                 Point3d p0,
                                 Point3d p1,
                                 double r)

testEllipsoidSurfaceTangent

public void testEllipsoidSurfaceTangent()

testEllipsoidPenetrationDistance

public void testEllipsoidPenetrationDistance(boolean printInfo)

testEllipseDist

public void testEllipseDist(double a,
                            double b,
                            double theta,
                            double dratio)

Test nearestPointEllipse() for an ellipse with minor axis lengths a and b. This method works in reverse, by starting with a point pchk on the ellipse defined by the parametric coordinate theta, and then finding a query point q for which pchk is the nearest point. q is determined by moving away from pchk along the direction of the curve normal nrm at pchk by a distance dchk, such that

    q = pchk + dchk * nrm.
 

dchk is determined from

    dchk = dratio * ndist
 

where ndist is the distance along the normal from pchk to the boundary of its quadrant. In cases where pchk lies on the x or y axis, and the resulting q is inside the ellipse (i.e., dratio < 0), it may be necessary to futher restrict dchk.

Given q and dchk, this method then verifies that

    d = nearestPointEllipse (p, a, b, q);
 

returns d and p values that match dchk and pchk.

testEllipseDist

public void testEllipseDist(double a,
                            double b,
                            double p0x,
                            double p0y,
                            double pnx,
                            double pny)

testEllipseDistance

public void testEllipseDistance()

Test nearestPointEllipse()

clipDratio

public double clipDratio(double a,
                         double b,
                         double dratio)

testEllipsoidDist

public void testEllipsoidDist(double a,
                              double b,
                              double c,
                              double theta,
                              double phi,
                              double dratio)

Test nearestPointEllipsoid() for an ellipsoid with minor axis lengths a, b, and c. This method works in reverse, by starting with a point pchk on the ellipsoid defined by the parametric coordinates theta andphi, and then finding a query point q for which pchk is the nearest point. q is determined by moving away from pchk along the direction of the surface normal nrm at pchk by a distance dchk, such that

    q = pchk + dchk * nrm.
 

dchk is determined from

    dchk = dratio * ndist
 

where ndist is the distance along the normal from pchk to the boundary of its octant. In cases where pchk lies on the x/y, y/z or z/x planes and the resulting q is inside the ellipsoid (i.e., dratio < 0), it may be necessary to futher restrict dchk.

Given q and dchk, this method then verifies that

    d = nearestPointEllipsoid (p, a, b, c, q);
 

returns d and p values that match dchk and pchk.

timeEllipsoidEberly

public void timeEllipsoidEberly(double a,
                                double b,
                                double c,
                                int numtests)

timeEllipsoidLloyd

public void timeEllipsoidLloyd(double a,
                               double b,
                               double c,
                               int numtests)

testEllipsoidDistance

public void testEllipsoidDistance()

Test nearestPointEllipsoid()

test

public void test()

Overrides:

test in class UnitTest

main

public static void main(java.lang.String[] args)