package com.nr.test.test_chapter7;
import static com.nr.NRUtil.SQR;
import static java.lang.Math.abs;
import static java.lang.Math.acos;
import static java.lang.Math.sqrt;
import static org.junit.Assert.fail;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.netlib.util.doubleW;
import com.nr.ran.VEGAS;
public class Test_vegas {
@Before
public void setUp() throws Exception {
}
@After
public void tearDown() throws Exception {
}
@Test
public void test() {
doubleW tgral= new doubleW(0),sd= new doubleW(0),chi2a= new doubleW(0);
double R1=3.0,R2=1,PI=acos(-1.0);
double[] regn =new double[6];
boolean localflag, globalflag=false;
// Test vegas
System.out.println("Testing vegas");
regn[0]=0.0;
regn[1]=-4.0;
regn[2]=-1.0;
regn[3]=4.0;
regn[4]=4.0;
regn[5]=1.0;
// Test #1: Compute volume of hemitorus
VEGAS vegas = new VEGAS() {
public double fxn(final double[] x, final double wgt){
return torusfunc1(x, wgt);
}
};
vegas.vegas(regn,0,1000,100,-1,tgral,sd,chi2a);
// System.out.printf(chi2a);
localflag = chi2a.val > 1.2;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** vegas: chi-square for test #1 is too high");
}
vegas.vegas(regn,1,100000,1,-1,tgral,sd,chi2a);
// System.out.printf(tgral << " %f\n", sd << " %f\n", chi2a);
// System.out.printf(SQR(PI)*R1*SQR(R2));
localflag = abs(tgral.val-SQR(PI)*R1*SQR(R2)) > 2.0*sd.val;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** vegas: Computation of hemitoroid volume is inaccurate");
}
// Test #2: Weight the integral by x
vegas = new VEGAS() {
public double fxn(final double[] x, final double wgt){
return torusfunc2(x, wgt);
}
};
vegas.vegas(regn,0,1000,100,-1,tgral,sd,chi2a);
// System.out.printf(chi2a);
localflag = chi2a.val > 1.2;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** vegas: chi-square for test #2 is too high");
}
vegas.vegas(regn,1,100000,1,-1,tgral,sd,chi2a);
// System.out.printf(tgral << " %f\n", sd << " %f\n", chi2a);
// System.out.printf(2.0*PI*SQR(R1)*SQR(R2)*(1+SQR(R2/R1)/4.0));
localflag = abs(tgral.val-2.0*PI*SQR(R1)*SQR(R2)*(1+SQR(R2/R1)/4.0)) > 2.0*sd.val;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** vegas: Computation of hemitoroid weighted by x is inaccurate");
}
// Test #3: Weight the integral by z^2
vegas = new VEGAS() {
public double fxn(final double[] x, final double wgt){
return torusfunc3(x, wgt);
}
};
vegas.vegas(regn,0,1000,100,-1,tgral,sd,chi2a);
// System.out.printf(chi2a);
localflag = chi2a.val > 1.2;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** vegas: chi-square for test #3 is too high");
}
vegas.vegas(regn,1,100000,1,-1,tgral,sd,chi2a);
// System.out.printf(tgral << " %f\n", sd << " %f\n", chi2a);
// System.out.printf(SQR(PI)*R1*SQR(SQR(R2))/4.0);
localflag = abs(tgral.val-SQR(PI)*R1*SQR(SQR(R2))/4.0) > 2.0*sd.val;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** vegas: Computation of hemitoroid weighted by z^2 is inaccurate");
}
if (globalflag) System.out.println("Failed\n");
else System.out.println("Passed\n");
}
double torusfunc1(final double[] x, final double wgt) {
double R1=3.0,R2=1.0;
if (SQR(x[2])+SQR(sqrt(SQR(x[0])+SQR(x[1]))-R1) <= R2) return 1.0;
else return 0.;
}
double torusfunc2(final double[] x, final double wgt) {
double R1=3.0,R2=1.0;
if (SQR(x[2])+SQR(sqrt(SQR(x[0])+SQR(x[1]))-R1) <= R2) return x[0];
else return 0.;
}
double torusfunc3(final double[] x, final double wgt) {
double R1=3.0,R2=1.0;
if (SQR(x[2])+SQR(sqrt(SQR(x[0])+SQR(x[1]))-R1) <= R2) return SQR(x[2]);
else return 0.;
}
}