3D Bubble Charts in MATLAB^®

Plot Random Bubbles

Define a set of bubble coordinates as the vectors x, y, and z. Define sz as a vector that specifies the bubble sizes. Then create a bubble chart of x, y, and z.

x = rand(1,20);
y = rand(1,20);
z = rand(1,20);
sz = rand(1,20);
bubblechart3(x,y,z,sz);

fig2plotly()

plot00plotrandom_bubbles

Specify Bubble Colors

Define a set of bubble coordinates as the vectors x, y, and z. Define sz as a vector that specifies the bubble sizes. Then create a bubble chart of x, y, and z, and specify the color as red. By default, the bubbles are partially transparent.

x = rand(1,20);
y = rand(1,20);
z = rand(1,20);
sz = rand(1,20);
bubblechart3(x,y,z,sz,'red');

fig2plotly()

plot10specifybubble_colors

For a custom color, you can specify an RGB triplet or a hexadecimal color code. For example, the hexadecimal color code '#7031BB', specifies a shade of purple.

bubblechart3(x,y,z,sz,'#7031BB');

fig2plotly()

plot11specifybubble_colors

You can also specify a different color for each bubble. For example, specify a vector to select colors from the figure's colormap.

c = 1:20;
bubblechart3(x,y,z,sz,c)

fig2plotly()

plot12specifybubble_colors

Specify Bubble Transparency and Outline Color

Define a set of bubble coordinates as the vectors x, y, and z. Define sz as a vector that specifies the bubble sizes. Then create a bubble chart of x, y, and z. By default, the bubbles are 60% opaque, and the edges are completely opaque with the same color.

x = rand(1,20);
y = rand(1,20);
z = rand(1,20);
sz = rand(1,20);
bubblechart3(x,y,z,sz);

fig2plotly()

plot20specifybubbletransparencyandoutlinecolor

You can customize the opacity and the outline color by setting the MarkerFaceAlpha and MarkerEdgeColor properties, respectively. One way to set a property is by specifying a name-value pair argument when you create the chart. For example, you can specify 20% opacity by setting the MarkerFaceAlpha value to 0.20.

bc = bubblechart3(x,y,z,sz,'MarkerFaceAlpha',0.20);

fig2plotly()

plot21specifybubbletransparencyandoutlinecolor

If you create the chart by calling the bubblechart3 function with a return argument, you can use the return argument to set properties on the chart after creating it. For example, you can change the outline color to purple.

bc.MarkerEdgeColor = [0.5 0 0.5];

fig2plotly()

plot22specifybubbletransparencyandoutlinecolor

Add a Bubble Legend

Define a data set that shows the contamination levels of a certain toxin across different towns in a metropolitan area.

• Define towns as the populations of the towns.
• Define nsites as the number of industrial sites in the corresponding towns.
• Define nregulated as the number of industrial sites that conform to the local environmental regulations.
• Define levels as the contamination levels in the towns.

  towns = randi([25000 500000],[1 30]);
  nsites = randi(10,1,30);
  nregulated = (-3 * nsites) + (5 * randn(1,30) + 20);
  levels = (3 * nsites) + (7 * randn(1,30) + 20);
  

Display the data in a bubble chart. Create axis labels using the xlabel, ylabel, and zlabel functions. Use the bubblesize function to make all the bubbles between 5 and 30 points in diameter. Then add a bubble legend that shows the relationship between bubble size and population.

bubblechart3(nsites,nregulated,levels,towns)
xlabel('Industrial Sites')
ylabel('Regulated Sites')
zlabel('Contamination Level')

bubblesize([5 30])
bubblelegend('Town Population','Location','eastoutside')

fig2plotly()

plot30addabubblelegend

Display Bubbles in Different Axes on the Same Scale

Define two sets of data that show the contamination levels of a certain toxin across different towns on the east and west sides of a certain metropolitan area.

• Define towns1 and towns2 as the populations of the towns.
• Define nsites1 and nsites2 as the number of industrial sites in the corresponding towns.
• Define nregulated1 and nregulated2 as the number of industrial sites that conform to the local environmental regulations.
• Define levels1 and levels2 as the contamination levels in the towns.

  towns1 = randi([25000 500000],[1 30]);
  towns2 = towns1/3;
  nsites1 = randi(10,1,30);
  nsites2 = randi(10,1,30);
  nregulated1 = (-3 * nsites1) + (5 * randn(1,30) + 20);
  nregulated2 = (-2 * nsites2) + (5 * randn(1,30) + 20);
  levels1 = (3 * nsites1) + (7 * randn(1,30) + 20);
  levels2 = (5 * nsites2) + (7 * randn(1,30) + 20);
  

Create a tiled chart layout so you can visualize the data side-by-side. Then create an axes object in the first tile and plot the data for the east side of the city. Add a title and axis labels. Then repeat the process in the second tile to plot the west side data.

tiledlayout(2,1,'TileSpacing','compact')
ax1 = nexttile;

% East side
bubblechart3(ax1,nsites1,nregulated1,levels1,towns1);
title('East Side')
xlabel('Industrial Sites')
ylabel('Regulated Sites')
zlabel('Contamination Level')

% West side
ax2 = nexttile;
bubblechart3(ax2,nsites2,nregulated2,levels2,towns2);
title('West Side')
xlabel('Industrial Sites')
ylabel('Regulated Sites')
zlabel('Contamination Level')

fig2plotly()

plot40displaybubblesindifferentaxesonthesame_scale

Reduce all the bubble sizes to make it easier to see all the bubbles. In this case, change the range of diameters to be between 5 and 20 points.

bubblesize(ax1,[5 20])
bubblesize(ax2,[5 20])

fig2plotly()

plot41displaybubblesindifferentaxesonthesame_scale

The east side towns are three times the size of the west side towns, but the bubble sizes do not reflect this information in the preceding charts. This is because the smallest and largest bubbles map to the smallest and largest data points in each of the axes. To display the bubbles on the same scale, define a vector called alltowns that includes the populations from both sides of the city. The use the bubblelim function to reset the scaling for both charts.

alltowns = [towns1 towns2];
newlims = [min(alltowns) max(alltowns)];
bubblelim(ax1,newlims)
bubblelim(ax2,newlims)

fig2plotly()

plot42displaybubblesindifferentaxesonthesame_scale