Fix Unit tests for Concatenation

Issue #186 Fixed tests which failed when I did work on this issue.
Also removed an attempt to combine two index matrices into one.

src/AudioAnalysisTools/LongDurationSpectrograms/Zooming/ZoomCommon.cs

@@ -40,10 +40,17 @@ public static (Dictionary<string, double[,]>, Dictionary<string, IndexProperties
                 analysisTag,
                 keys.ToArray());
 
+            /*
+            // THE FOLLOWING IDEA TO MAKE A COMBINED MATRIX OF BGN and RHZ was rejected.
+            // Anthony was concerned that the BGN matrix alone was not conveying much information at high resolutions.
+            // The idea was to combine another matrix with the BGN matrix.
+            // I tried three combinations, BGN-RHZ, BGN-OSC and BGN-SPT. None of them appeard to provide additional useful information at high resolution.
+            // The problem is that at high resolution, i.e. approaching 0.1s for an analysis unit, there are not many orthogonal features in a single frequency bin.
             // Make a BNG COMBINATION Spectral matrix.
             //var comboMatrix = MatrixTools.MaxOfTwoMatrices(spectra["BNG"], spectra["RHZ"]);
             var comboMatrix = MatrixTools.AddMatricesWeightedSum(spectra["BGN"], 1.0, spectra[comboIndexID], 10.0);
             spectra["BGN"] = comboMatrix;
+            */
 
             return (spectra, relevantIndexProperties);
         }

tests/Acoustics.Test/AnalysisPrograms/Concatenation/ConcatenationTests.cs

@@ -104,7 +104,7 @@ public void ConcatenateEverythingYouCanLayYourHandsOn()
             var actualImage = ImageTools.ReadImage2Bitmap(imageFileInfo.FullName);
             Assert.That.ImageIsSize(722, 632, actualImage);
             Assert.That.PixelIsColor(new Point(100, 100), Color.FromArgb(211, 211, 211), actualImage);
-            Assert.That.PixelIsColor(new Point(200, 125), Color.FromArgb(47, 34, 255), actualImage);
+            Assert.That.PixelIsColor(new Point(200, 125), Color.FromArgb(60, 44, 255), actualImage);
             Assert.That.PixelIsColor(new Point(675, 600), Color.FromArgb(255, 105, 180), actualImage);
         }
 
@@ -160,8 +160,8 @@ public void ConcatenateIndexFilesTest24Hour()
 
             // we expect only the second half (past midnight) of the image to be rendered
             Assert.That.ImageIsSize(512, 632, actualImage);
-            Assert.That.PixelIsColor(new Point(105, 154), Color.FromArgb(21, 200, 255), actualImage);
-            Assert.That.PixelIsColor(new Point(100, 160), Color.FromArgb(0, 69, 131), actualImage);
+            Assert.That.PixelIsColor(new Point(105, 154), Color.FromArgb(34, 30, 255), actualImage);
+            Assert.That.PixelIsColor(new Point(100, 160), Color.FromArgb(0, 79, 132), actualImage);
         }
 
         /// <summary>
@@ -217,7 +217,7 @@ public void ConcatenateIndexFilesTest24HourWithoutDateRange()
             var actualImage1 = ImageTools.ReadImage2Bitmap(image1FileInfo.FullName);
             Assert.That.ImageIsSize(210, 632, actualImage1);
             Assert.That.PixelIsColor(new Point(100, 100), Color.FromArgb(211, 211, 211), actualImage1);
-            Assert.That.PixelIsColor(new Point(50, 50), Color.FromArgb(66, 17, 14), actualImage1);
+            Assert.That.PixelIsColor(new Point(50, 50), Color.FromArgb(86, 27, 16), actualImage1);
 
             // IMAGE 2: Compare image files - check that image exists and dimensions are correct
             var dateString2 = "20160726";
@@ -232,7 +232,7 @@ public void ConcatenateIndexFilesTest24HourWithoutDateRange()
 
             var actualImage2 = ImageTools.ReadImage2Bitmap(image2FileInfo.FullName);
             Assert.That.ImageIsSize(512, 632, actualImage2);
-            Assert.That.PixelIsColor(new Point(50, 124), Color.FromArgb(57, 28, 255), actualImage2);
+            Assert.That.PixelIsColor(new Point(50, 124), Color.FromArgb(70, 37, 255), actualImage2);
             Assert.That.PixelIsColor(new Point(460, 600), Color.FromArgb(255, 105, 180), actualImage2);
         }
 

tests/Acoustics.Test/AudioAnalysisTools/LongDurationSpectrograms/Zooming/ZoomCommonTests.cs

@@ -26,7 +26,7 @@ public ZoomCommonTests()
 
         /// <summary>
         /// This test is designed to ensure that images are produced at the correct length.
-        /// We had a beviour where they were being trimmed by a whole pixel at the end of
+        /// We had a behaviour where they were being trimmed by a whole pixel at the end of
         /// recordings that didn't wholly fill a minute. At very low scales this is acceptable, but
         /// at high scales just because 1/6th of a pixel's worth of data is absent does not mean
         /// that we shouldn't render the other 5/6ths of the pixel. And if we don't, it creates