package com.nr.test.test_chapter6;
import static com.nr.NRUtil.buildVector;
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.sf.Erf;
public class Test_Erf {
@Before
public void setUp() throws Exception {
}
@After
public void tearDown() throws Exception {
}
@Test
public void test() {
int i,N=13;
double sbeps;
double x[]={-4.0,-3.0,-2.0,-1.0,-0.5,-0.1,0.0,0.1,0.5,1.0,2.0,3.0,4.0};
double y1[]={-9.999999845827421e-1,-9.999779095030015e-1,-9.953222650189527e-1,
-8.427007929497148e-1,-5.204998778130465e-1,-1.124629160182849e-1,0.0,
1.124629160182849e-1,5.204998778130465e-1,8.427007929497148e-1,
9.953222650189527e-1,9.999779095030015e-1,9.999999845827421e-1};
double y2[]={1.999999984582742e+000,1.999977909503002e+000,1.995322265018953e+000,
1.842700792949715e+000,1.520499877813047e+000,1.112462916018285e+000,1.0,
8.875370839817152e-001,4.795001221869535e-001,1.572992070502852e-001,
4.677734981047265e-003,2.209049699858543e-005,1.541725790028003e-008};
double[] xx=buildVector(x),yy1=buildVector(y1),yy2=buildVector(y2),zz1= new double[N],zz2= new double[N],zz3= new double[N],zz4= new double[N];
boolean localflag, globalflag=false;
// Test Erf
System.out.println("Testing Erf");
Erf e = new Erf();
for (i=0;i<N;i++) {
zz1[i]=e.erf(xx[i]);
zz2[i]=e.erfc(xx[i]);
}
sbeps=5.e-15;
System.out.printf("Erf, erf(): Maximum discrepancy = %f\n", maxel(vecsub(zz1,yy1)));
localflag = maxel(vecsub(zz1,yy1)) > sbeps;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** Erf, erf(): Incorrect function values");
}
sbeps=5.e-15;
System.out.printf("Erf, erfc(): Maximum discrepancy = %f\n", maxel(vecsub(zz2,yy2)));
localflag = maxel(vecsub(zz2,yy2)) > sbeps;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** Erf, erfc(): Incorrect function values");
}
for (i=0;i<N;i++) {
zz3[i]=e.inverf(zz1[i]);
zz4[i]=e.inverfc(zz2[i]);
}
sbeps=1.e-9;
System.out.printf("Erf, inverf(): Maximum discrepancy = %f\n", maxel(vecsub(zz3,xx)));
localflag = maxel(vecsub(zz3,xx)) > sbeps;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** Erf, inverf(): Inversion does not return to original arguments");
}
sbeps=1.e-9;
System.out.printf("Erf, inverfc(): Maximum discrepancy = %f\n", maxel(vecsub(zz4,xx)));
localflag = maxel(vecsub(zz4,xx)) > sbeps;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** Erf, inverfc(): Inversion does not return to original arguments");
}
if (globalflag) System.out.println("Failed\n");
else System.out.println("Passed\n");
}
}