package com.nr.test.test_chapter4;
import static com.nr.fi.GaussianWeights.gauleg;
import static com.nr.test.NRTestUtil.maxel;
import static com.nr.test.NRTestUtil.vecsub;
import static org.junit.Assert.fail;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.nr.UniVarRealValueFun;
import com.nr.sf.Bessjy;
public class Test_gauleg {
@Before
public void setUp() throws Exception {
}
@After
public void tearDown() throws Exception {
}
@Test
public void test() {
int i,j,N=10,M=10;
double x1,x2,val,sbeps=51.e-14;
double[] y= new double[N],yy= new double[N],x= new double[M],w= new double[M];
boolean localflag, globalflag=false;
// Test gauleg
System.out.println("Testing gauleg");
Bessj0_gauleg bj0 = new Bessj0_gauleg();
Bessj1_gauleg bj1 = new Bessj1_gauleg();
for (i=0;i<N;i++) {
x1=1.0*i;
x2=x1+2.0;
gauleg(x1,x2,x,w);
val=0.0;
for (j=0;j<M;j++) val += w[j]*bj1.funk(x[j]);
y[i]=val;
yy[i]=bj0.funk(x1)-bj0.funk(x2);
}
System.out.printf("gauleg: Maximum discrepancy = %f\n", maxel(vecsub(y,yy)));
localflag = maxel(vecsub(y,yy)) > sbeps;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** gauleg: Failure to achieve accurate integral");
}
if (globalflag) System.out.println("Failed\n");
else System.out.println("Passed\n");
}
class Bessj0_gauleg implements UniVarRealValueFun{
public double funk (double x) {
Bessjy b=new Bessjy();
return(b.j0(x));
}
};
class Bessj1_gauleg implements UniVarRealValueFun{
public double funk (double x) {
Bessjy b =new Bessjy();
return(b.j1(x));
}
};
}