replace SetColormap() with a public property

Author: swharden

src/Spectrogram.MicrophoneDemo/FormMicrophone.cs

@@ -105,7 +105,7 @@ private void timer1_Tick(object sender, EventArgs e)
 
         private void cbColormap_SelectedIndexChanged(object sender, EventArgs e)
         {
-            spec.SetColormap(cmaps[cbColormap.SelectedIndex]);
+            spec.Colormap = cmaps[cbColormap.SelectedIndex];
         }
 
         private void btnResetRoll_Click(object sender, EventArgs e)

src/Spectrogram.Tests/ColormapExamples.cs

@@ -21,7 +21,7 @@ public void Test_Make_CommonColormaps()
 
             foreach (var cmap in Colormap.GetColormaps())
             {
-                spec.SetColormap(cmap);
+                spec.Colormap = cmap;
                 spec.SaveImage($"../../../../../dev/graphics/hal-{cmap.Name}.png");
                 Debug.WriteLine($"![](dev/graphics/hal-{cmap.Name}.png)");
             }

src/Spectrogram/SpectrogramGenerator.cs

@@ -79,6 +79,10 @@ public class SpectrogramGenerator
         private readonly List<double[]> ffts = new List<double[]>();
         private readonly List<double> newAudio;
         private Colormap cmap = Colormap.Viridis;
+        /// <summary>
+        /// Colormap to use when generating future FFTs.
+        /// </summary>
+        public Colormap Colormap = Colormap.Viridis;
 
         /// <summary>
         /// Instantiate a spectrogram generator.
@@ -129,12 +133,13 @@ public override string ToString()
                    $"overlap: {settings.StepOverlapFrac * 100:N0}%";
         }
 
+        [Obsolete("Assign to the Colormap field")]
         /// <summary>
         /// Set the colormap to use for future renders
         /// </summary>
         public void SetColormap(Colormap cmap)
         {
-            this.cmap = cmap ?? this.cmap;
+            Colormap = cmap ?? this.Colormap;
         }
 
         /// <summary>