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# Compare Data Sets Using Overlayed Area Graphs

This example shows how to compare two data sets by overlaying their area graphs.

### Overlay Two Area Graphs

Create the sales and expenses data from the years 2004 to 2008.

```years = 2004:2008; sales = [51.6 82.4 90.8 59.1 47.0]; expenses = [19.3 34.2 61.4 50.5 29.4];```

Display sales and expenses as two separate area graphs in the same axes. First, plot an area graph of `sales`. Change the color of the area graph by setting the `FaceColor` and `EdgeColor` properties using RGB triplet color values.

`area(years,sales,'FaceColor',[0.5 0.9 0.6],'EdgeColor',[0 0.5 0.1])`

Use the `hold` command to prevent a new graph from replacing the existing graph. Plot a second area graph of `expenses`. Then, set the `hold` state back to `off`.

```hold on area(years,expenses,'FaceColor',[0.7 0.7 0.7],'EdgeColor','k') hold off```

### Add Grid Lines

Set the tick marks along the x-axis to correspond to whole years. Draw a grid line for each tick mark. Display the grid lines on top of the area graphs by setting the `Layer` property. Use dot notation to set properties.

```ax = gca; % current axes ax.XTick = years; ax.XGrid = 'on'; ax.Layer = 'top';```

### Add Title, Axis Labels, and Legend

Give the graph a title and add axis labels. Add a legend to the graph to indicate the areas of profits and expenses.

```title('Profit Margin for 2004 to 2008') xlabel('Years') ylabel('Expenses + Profits = Sales in 1000s') legend('Profits','Expenses')```