package com.nr.test.test_chapter9;
import static com.nr.root.Roots.zroots;
import static com.nr.test.NRTestUtil.maxel;
import static org.junit.Assert.fail;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.nr.Complex;
public class Test_zroots {
@Before
public void setUp() throws Exception {
}
@After
public void tearDown() throws Exception {
}
@Test
public void test() {
int i,N=5;
boolean polish=true;
double sbeps=1.e-14;
Complex re1 = new Complex(1.0,0.0),im1=new Complex(0.0,1.0);
Complex a[]={
re1.mul(2.0).add(im1),
im1.mul(2.0),
re1.mul(3.0).add(im1),
re1.add(im1.mul(2.0)),
re1.sub(im1),
new Complex(1.0)
};
Complex[] aa = new Complex[N+1];System.arraycopy(a, 0, aa, 0 , N+1);
Complex[] rts = new Complex[N];
double[] dy=new double[N];
boolean localflag, globalflag=false;
// Test zroots
System.out.println("Testing zroots");
// Roots of polynomial x^5+(1-i)x^4+(1+2i)x^3+(3+i)x^2+(2i)x+(2+i)"
// Roots are x=i, x=-i, x=sqrt(2i), x=-i*sqrt(2i), x=(i-1)
zroots(aa,rts,polish);
for (i=0;i<N;i++) {
Complex r = a[4].add(rts[i].mul(a[5]));
r = a[3].add(rts[i].mul(r));
r = a[2].add(rts[i].mul(r));
r = a[1].add(rts[i].mul(r));
r = a[0].add(rts[i].mul(r));
dy[i]=r.abs();
}
System.out.printf("zroots: Maximum discrepancy = %f\n", maxel(dy));
localflag = maxel(dy) > sbeps;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** zroots: Incorrect roots");
}
if (globalflag) System.out.println("Failed\n");
else System.out.println("Passed\n");
}
}