// Example 103 from page 77

//

class Example103 {

public static void main(String[] args) {

mathtest();

}

static void mathtest() {

print("Illegal arguments, NaN results:");

print(Math.sqrt(-1)); // NaN

print(Math.log(-1)); // NaN

print(Math.pow(-1, 2.5)); // NaN

print(Math.acos(1.1)); // NaN

print("Infinite results:");

print(Math.log(0)); // -Infinity

print(Math.pow(0, -1)); // Infinity

print(Math.exp(1000.0)); // Infinity (overflow)

print("Infinite arguments:");

double infinity = Double.POSITIVE_INFINITY;

print(Math.sqrt(infinity)); // Infinity

print(Math.log(infinity)); // Infinity

print(Math.exp(-infinity)); // 0.0

print("NaN arguments and special cases:");

double nan = Math.log(-1);

print(Math.sqrt(nan)); // NaN

print(Math.pow(nan, 0)); // 1.0 (special case)

print(Math.pow(0, 0)); // 1.0 (special case)

print(Math.round(nan)); // 0 (special case)

print(Math.round(1E50)); // 9223372036854775807 (Long.MAX_VALUE)

// For all (x, y) except (0.0, 0.0):

// sign(cos(atan2(y, x))) == sign(x) && sign(sin(atan2(y, x))) == sign(y)

for (double x=-100; x<=100; x+=0.125) {

for (double y=-100; y<=100; y+=0.125) {

double r = Math.atan2(y, x);

if (!(sign(Math.cos(r))==sign(x) && sign(Math.sin(r))==sign(y)))

print("x = " + x + "; y = " + y);

}

}

}

static int sign(double x) {

final double tolerance = 1E-14;

if (x < -tolerance)

return -1;

else if (x > +tolerance)

return +1;

else

return 0;

}

static void print(String d) {

System.out.println(d);

}

static void print(double d) {

System.out.println(d);

}

static void print(long d) {

System.out.println(d);

}

}