package com.nr.test.test_chapter10;
import static java.lang.Math.abs;
import static org.junit.Assert.fail;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.nr.UniValRealValueFunWithDiff;
import com.nr.min.Dbrent;
import com.nr.sf.Bessjy;
public class Test_Dbrent {
@Before
public void setUp() throws Exception {
}
@After
public void tearDown() throws Exception {
}
@Test
public void test() {
int i,N=50;
double a,b,min,span=1.0,sbeps=1.0e-7;
boolean localflag=false, globalflag=false;
// Test Dbrent
System.out.println("Testing Dbrent");
Funcd_Dbrent funcd = new Funcd_Dbrent();
Dbrent dbr = new Dbrent();
for (i=0;i<N;i++) {
a=i;
b=a+span;
dbr.bracket(a,b,funcd);
min=dbr.minimize(funcd); // Minimum of bessj0
localflag = localflag || (abs(funcd.df(min)) > sbeps);
}
globalflag = globalflag || localflag;
if (localflag) {
fail("*** Dbrent: Identified minimum is not a zero of the function derivative");
}
if (globalflag) System.out.println("Failed\n");
else System.out.println("Passed\n");
}
class Funcd_Dbrent implements UniValRealValueFunWithDiff{
Bessjy b = new Bessjy();
public double funk (final double x) {
return b.j0(x);
}
public double df(final double x) {
return -b.j1(x);
}
};
}