Fix regression caused by unique.

- Now the calcKernelDensity function returns the mean value for "value" if min and max from data are equal. Which was likely the cause in the errors for interp1.
- To test this case, fake data for MPG is added in the testviolinplot.m file.

	modified:   test_cases/testviolinplot.m

	modified:   Violin.m
	modified:   test_cases/testviolinplot.m

Violin.m

@@ -201,7 +201,7 @@
 
             %% Plot the data points within the violin area
             if length(density) > 1
-               jitterstrength = interp1(unique(value), unique(density*width), data);
+               jitterstrength = interp1(value, density*width, data, 'linear','extrap');
             else % all data is identical:
                 jitterstrength = density*width;
             end
@@ -314,7 +314,7 @@
             %% Plot the data mean
             meanValue = mean(data);
             if length(density) > 1
-                meanDensityWidth = interp1(unique(value), unique(density), meanValue)*width;
+                meanDensityWidth = interp1(value, density, meanValue,'linear','extrap')*width;
             else % all data is identical:
                 meanDensityWidth = density*width;
             end
@@ -695,6 +695,7 @@
             % all data is identical
             if min(data) == max(data)
                 density = 1;
+                value= mean(value);
             end
 
             width = width/max(density);

test_cases/testviolinplot.m

@@ -38,7 +38,7 @@ function testviolinplot()
 disp('Test 4: Test two sided violin plots. Japan is being compared.');
 subplot(2,4,4); 
 C = colororder;
-vs4 = violinplot({thisData,repmat(thisData(:,5),1,7)},catnames_labels,'ViolinColor',{C,C(5,:)},'ViolinAlpha',{0.3 0.3});
+vs4 = violinplot({thisData,repmat(thisData(:,5),1,7)},catnames_labels,'ViolinColor',{C,C(5,:)},'ViolinAlpha',{0.3 0.3}, 'ShowMean', true);
 plotdetails(4);
 
 % TEST CASE 5
@@ -65,13 +65,15 @@ function testviolinplot()
 % TEST CASE 8
 disp('Test 8: Same as previous one, just removing the data of half of the violins afterwards.');
 subplot(2,4,8); 
-vs5 = violinplot(MPG, Origin, 'QuartileStyle','shadow', 'HalfViolin','left',...
-     'DataStyle', 'histogram', 'ShowMean', false);
+vs5 = violinplot([MPG; 5;5;5;5;5], [Origin; 'test';'test';'test';'test';'test'], 'QuartileStyle','shadow', 'HalfViolin','full',...
+     'DataStyle', 'scatter', 'ShowMean', false);
 plotdetails(8);
 for n= 1:round(length(vs5)/2)
     vs5(1,n).ShowData = 0;
 end
+xlim([0, 9]);
 %other test cases could be added here
+
 end 
 
 function plotdetails(n)