changeset 46:c666067fb8da

Comments

--- a/test/TestPeakInterpolator.cpp	Tue Aug 14 16:48:19 2012 +0100
+++ b/test/TestPeakInterpolator.cpp	Wed Aug 15 14:53:28 2012 +0100
@@ -33,40 +33,52 @@
 
 BOOST_AUTO_TEST_CASE(peakAtSample_N3)
 {
-    double data[] = { 0.0, 1.0, 0.0 };
+    // Peak exactly at sample index
+    double data[] = { 0.0, 10.0, 0.0 };
     PeakInterpolator p;
+    // Asked to find peak at index 1, should return index 1
     double result = p.findPeakLocation(data, 3, 1);
     BOOST_CHECK_EQUAL(result, 1.0);
+    // Asked to find any peak, should return index 1
     result = p.findPeakLocation(data, 3);
     BOOST_CHECK_EQUAL(result, 1.0);
 }
 
 BOOST_AUTO_TEST_CASE(peakAtSample_N5)
 {
-    double data[] = { 0.0, 1.0, 2.0, 1.0, 0.0 };
+    // Peak exactly at sample index
+    double data[] = { 0.0, 10.0, 20.0, 10.0, 0.0 };
     PeakInterpolator p;
+    // Asked to find peak at index 2, should return index 2
     double result = p.findPeakLocation(data, 5, 2);
     BOOST_CHECK_EQUAL(result, 2.0);
+    // Asked to find any peak, should return index 2
     result = p.findPeakLocation(data, 5);
     BOOST_CHECK_EQUAL(result, 2.0);
 }
 
 BOOST_AUTO_TEST_CASE(flat)
 {
+    // No peak
     double data[] = { 1.0, 1.0, 1.0, 1.0, 1.0 };
     PeakInterpolator p;
+    // Asked to find peak at index N, should return N (no superior neighbours)
     double result = p.findPeakLocation(data, 5, 2);
     BOOST_CHECK_EQUAL(result, 2.0);
+    // Asked to find any peak, should return 0 (first value as good as any)
     result = p.findPeakLocation(data, 5);
     BOOST_CHECK_EQUAL(result, 0.0);
 }
 
 BOOST_AUTO_TEST_CASE(multiPeak)
 {
+    // More than one peak
     double data[] = { 1.0, 2.0, 1.0, 2.0, 1.0 };
     PeakInterpolator p;
+    // Asked to find peak at index 3, should return index 3
     double result = p.findPeakLocation(data, 5, 3);
     BOOST_CHECK_EQUAL(result, 3.0);
+    // But asked to find any peak, should return 1 (first peak)
     result = p.findPeakLocation(data, 5);
     BOOST_CHECK_EQUAL(result, 1.0);
 }
@@ -74,7 +86,7 @@
 BOOST_AUTO_TEST_CASE(start)
 {
     // Can't meaningfully interpolate if we're identifying element 0
-    // as the peak
+    // as the peak (nothing to its left)
     double data[] = { 1.0, 1.0, 0.0, 0.0 };
     PeakInterpolator p;
     double result = p.findPeakLocation(data, 4, 0);
@@ -88,24 +100,30 @@
     PeakInterpolator p;
     double result = p.findPeakLocation(data, 4, 3);
     BOOST_CHECK_EQUAL(result, 3.0);
-    // But when running without a peak location, we expect idx 2 to be
-    // picked as peak, not idx 3, so that will result in interpolation
+    // But when asked to find any peak, we expect idx 2 to be picked,
+    // not idx 3, so that will result in interpolation
     result = p.findPeakLocation(data, 4);
     BOOST_CHECK(result > 2.0 && result < 3.0);
 }
 
 BOOST_AUTO_TEST_CASE(longHalfway)
 {
+    // Peak is exactly half-way between indices
     double data[] = { 1.0, 1.0, 1.0, 2.0, 2.0, 1.0, 1.0, 1.0 };
     PeakInterpolator p;
-    double result = p.findPeakLocation(data, 8, 4);
+    // Asked to find peak for either index 3 or 4, should return 3.5
+    double result = p.findPeakLocation(data, 8, 3);
     BOOST_CHECK_EQUAL(result, 3.5);
+    result = p.findPeakLocation(data, 8, 4);
+    BOOST_CHECK_EQUAL(result, 3.5);
+    // Likewise if asked to find any peak
     result = p.findPeakLocation(data, 8);
     BOOST_CHECK_EQUAL(result, 3.5);
 }
 
 BOOST_AUTO_TEST_CASE(shortHalfway)
 {
+    // As longHalfway, but with fewer points
     double data[] = { 1.0, 2.0, 2.0, 1.0 };
     PeakInterpolator p;
     double result = p.findPeakLocation(data, 4, 1);
@@ -116,6 +134,9 @@
 
 BOOST_AUTO_TEST_CASE(aboveHalfway)
 {
+    // Peak is nearer to one index than its neighbour. (Exact position
+    // depends on the peak interpolation method in use; we only know
+    // that it must be beyond the half way point)
     double data[] = { 1.0, 1.5, 2.0, 1.0 };
     PeakInterpolator p;
     double result = p.findPeakLocation(data, 4, 2);
@@ -126,6 +147,9 @@
 
 BOOST_AUTO_TEST_CASE(belowHalfway)
 {
+    // Peak is nearer to one index than its neighbour. (Exact position
+    // depends on the peak interpolation method in use; we only know
+    // that it must be before the half way point)
     double data[] = { 1.0, 2.0, 1.5, 1.0 };
     PeakInterpolator p;
     double result = p.findPeakLocation(data, 4, 1);