package com.nr.test.test_chapter13;
import static com.nr.NRUtil.SQR;
import static java.lang.Math.abs;
import static java.lang.Math.acos;
import static java.lang.Math.cos;
import static org.junit.Assert.fail;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.nr.sp.Spectreg;
import com.nr.sp.SquareWin;
public class Test_Square {
@Before
public void setUp() throws Exception {
}
@After
public void tearDown() throws Exception {
}
@Test
public void test() {
double maxf=0,maxs,pi=acos(-1.0),sbeps;;
int i,j,maxi=0,M=128,N=2*M,K=64;
double[] data=new double[N],spec=new double[M+1],freq=new double[M+1];
boolean localflag, globalflag=false;
// Test square
System.out.println("Testing square");
SquareWin square = new SquareWin();
Spectreg sp = new Spectreg(M);
for (i=0;i<K;i++) {
// Generate a data set
for (j=0;j<N;j++)
data[j]=cos(2.0*pi*64*j/N);
sp.adddataseg(data,square);
}
spec=sp.spectrum();
freq=sp.frequencies();
// for (i=0;i<M+1;i++)
// System.out.printf(freq[i] << " %f\n", spec[i]);
maxs=-1.0;
for (i=0;i<M+1;i++) {
if (spec[i] > maxs) {
maxf=freq[i];
maxs=spec[i];
maxi=i;
}
}
sbeps=1.e-15;
localflag=abs(maxf-0.25) > sbeps;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** square: Spectrum maximum is at wrong frequency");
}
localflag = false;
for (i=1;i<10;i++) {
localflag = localflag || (spec[maxi+i]/maxs > sbeps);
localflag = localflag || (spec[maxi-i]/maxs > sbeps);
}
globalflag = globalflag || localflag;
if (localflag) {
fail("*** square: Channels adjacent to maximum should be zero for square window");
}
Spectreg sp2 = new Spectreg(M);
for (i=0;i<K;i++) {
// Generate a data set offset by 1/2 channel in frequency
for (j=0;j<N;j++)
data[j]=cos(2.0*pi*64.5*j/N);
sp2.adddataseg(data,square);
}
spec=sp2.spectrum();
freq=sp2.frequencies();
// for (i=0;i<10;i++)
// System.out.printf(spec[maxi-i]/maxs << " %f\n", spec[maxi+i+1]/maxs);
// test for symmetry
sbeps=1.e-2;
localflag=false;
for (i=0;i<5;i++) {
localflag = localflag || abs(spec[maxi-i]/spec[maxi+i+1]-1.0) > sbeps;
// System.out.printf(abs(spec[maxi-i]/spec[maxi+i+1]-1.0));
}
globalflag = globalflag || localflag;
if (localflag) {
fail("*** square: Sidelobes are not symmetrical");
}
// test for amplitude
sbeps=1.e-2;
for (i=1;i<5;i++) {
localflag = abs(spec[maxi-i]/spec[maxi]*SQR(2.0*i+1)-1.0) > sbeps;
// System.out.printf(abs(spec[maxi-i]/spec[maxi]*SQR(2.0*i+1)-1.0));
globalflag = globalflag || localflag;
if (localflag) {
fail("*** square: Sidelobes are not in correct proportion");
}
}
if (globalflag) System.out.println("Failed\n");
else System.out.println("Passed\n");
}
}