Examples with DD com.revolsys.geometry.math.DD used on opensource projects

Example 1 with DD

use of com.revolsys.geometry.math.DD in project com.revolsys.open by revolsys.

the class CGAlgorithmsDD method intersection.

/**
 * Computes an intersection point between two lines
 * using DD arithmetic.
 * Currently does not handle case of parallel lines.
 *
 * @param p1
 * @param p2
 * @param q1
 * @param q2
 * @return
 */
public static Point intersection(final Point p1, final Point p2, final Point q1, final Point q2) {
    final DD denom1 = DD.valueOf(q2.getY()).selfSubtract(q1.getY()).selfMultiply(DD.valueOf(p2.getX()).selfSubtract(p1.getX()));
    final DD denom2 = DD.valueOf(q2.getX()).selfSubtract(q1.getX()).selfMultiply(DD.valueOf(p2.getY()).selfSubtract(p1.getY()));
    final DD denom = denom1.subtract(denom2);
    /**
     * Cases:
     * - denom is 0 if lines are parallel
     * - intersection point lies within line segment p if fracP is between 0 and 1
     * - intersection point lies within line segment q if fracQ is between 0 and 1
     */
    final DD numx1 = DD.valueOf(q2.getX()).selfSubtract(q1.getX()).selfMultiply(DD.valueOf(p1.getY()).selfSubtract(q1.getY()));
    final DD numx2 = DD.valueOf(q2.getY()).selfSubtract(q1.getY()).selfMultiply(DD.valueOf(p1.getX()).selfSubtract(q1.getX()));
    final DD numx = numx1.subtract(numx2);
    final double fracP = numx.selfDivide(denom).doubleValue();
    final double x = DD.valueOf(p1.getX()).selfAdd(DD.valueOf(p2.getX()).selfSubtract(p1.getX()).selfMultiply(fracP)).doubleValue();
    final DD numy1 = DD.valueOf(p2.getX()).selfSubtract(p1.getX()).selfMultiply(DD.valueOf(p1.getY()).selfSubtract(q1.getY()));
    final DD numy2 = DD.valueOf(p2.getY()).selfSubtract(p1.getY()).selfMultiply(DD.valueOf(p1.getX()).selfSubtract(q1.getX()));
    final DD numy = numy1.subtract(numy2);
    final double fracQ = numy.selfDivide(denom).doubleValue();
    final double y = DD.valueOf(q1.getY()).selfAdd(DD.valueOf(q2.getY()).selfSubtract(q1.getY()).selfMultiply(fracQ)).doubleValue();
    return new PointDoubleXY(x, y);
}

Example 2 with DD

use of com.revolsys.geometry.math.DD in project com.revolsys.open by revolsys.

the class DDBasicTest method checkReciprocal.

private void checkReciprocal(final double x, final double errBound) {
    final DD xdd = new DD(x);
    final DD rr = xdd.reciprocal().reciprocal();
    final double err = xdd.subtract(rr).doubleValue();
    // System.out.println("DD Recip = " + xdd + " DD delta= " + err
    // + " double recip delta= " + (x - 1.0 / (1.0 / x)));
    assertTrue(err <= errBound);
}

Example 3 with DD

use of com.revolsys.geometry.math.DD in project com.revolsys.open by revolsys.

the class DDBasicTest method checkSqrt.

private void checkSqrt(final DD x, final double errBound) {
    final DD sqrt = x.sqrt();
    final DD x2 = sqrt.multiply(sqrt);
    checkErrorBound("Sqrt", x, x2, errBound);
}

Example 4 with DD

use of com.revolsys.geometry.math.DD in project com.revolsys.open by revolsys.

the class DDBasicTest method testDivideMultiply.

public void testDivideMultiply() {
    checkDivideMultiply(DD.PI, DD.E, 1e-30);
    checkDivideMultiply(new DD(39.4), new DD(10), 1e-30);
}

Example 5 with DD

use of com.revolsys.geometry.math.DD in project com.revolsys.open by revolsys.

the class DDBasicTest method checkBinomial2.

void checkBinomial2(final double a, final double b) {
    // binomial product
    final DD add = new DD(a);
    final DD bdd = new DD(b);
    final DD aPlusb = add.add(bdd);
    final DD aSubb = add.subtract(bdd);
    final DD abProd = aPlusb.multiply(aSubb);
    // System.out.println("(a+b)^2 = " + abSq);
    // expansion
    final DD a2dd = add.multiply(add);
    final DD b2dd = bdd.multiply(bdd);
    // System.out.println("2ab+b^2 = " + sum);
    // this should equal b^2
    final DD diff = abProd.subtract(a2dd).negate();
    // System.out.println("(a+b)^2 - a^2 = " + diff);
    final DD delta = diff.subtract(b2dd);
    // System.out.println();
    // System.out.println("A = " + a + ", B = " + b);
    // System.out.println("[DD] (a+b)(a-b) = " + abProd
    // + " -((a^2 - b^2) - a^2) = " + diff + " delta = " + delta);
    // printBinomialSquareDouble(a,b);
    final boolean isSame = diff.equals(b2dd);
    assertTrue(isSame);
    final boolean isDeltaZero = delta.isZero();
    assertTrue(isDeltaZero);
}