Issue 61

Using the Graph Magnifier

Grapher 8 includes the ability to magnify portions of your graph. This can be tremendously useful for emphasizing subtle but significant data variations within the graph. You can add a graph magnifier to any 2D graph by simply dragging a rectangle around the area you want to magnify. The magnified portion of the graph has its own set of axes that you can custom modify, independently from the source graph. This allows you to focus on a portion of the graph and still maintain a frame of reference.

This article describes how to create a graph with a graph magnifier, and then goes in detail on how to customize the magnifier to highlight the details of that portion of the graph.

Creating a graph and adding a graph magnifier
To create a graph with a graph magnifier, follow the steps outlined below. The magnifier will be created using the default settings.

1. To create a line graph, go to Graph | 2D XY Graphs | Line/Scatter.
2. Select the data file and click Open. For this example, I am using this file of historical Pepsi stock data. You can download it to use or follow along with any other data file.
3. The graph is automatically created using columns A and B for X and Y. Select Line/Scatter Plot 1 in the Object Manager.
4. In the Property Inspector, go to the Plot tab and be sure the X column and Y column designations are correct. Change any other properties you wish for the line graph, such as changing the line properties on the Line tab, or the fill properties on the Fill tab.
5. You can change the tick mark and grid line properties by selecting Y Axis 1 or X Axis 1 in the Object Manager. In the Property Inspector, you can add an axis title on the Axis tab, change the grid line properties on the Grid Lines tab, set the tick mark spacing and frequency on the Tick Marks tab, and the tick label properties on theTick Labels tab.
   
   Create a line/scatter plot and specify the plot and axis properties in the Property Inspector.
6. Once the properties of the graph are what you want them to be, right-click on the plot (either in the plot window or the Object Manager) and choose Add Magnifier. Alternatively, you can choose Graph | Add to Graph | Magnifier.
7. Your cursor will change to an arrow with two small boxes next to it: 
8. Drag the cursor around the area on the plot that you want to magnify. The magnifier is created.
   
   Right click over the plot and choose Add Magnifier.
   Drag your cursor over the area you want magnified and the magnifier is created.

Customizing the Magnifier
Once the magnifier is created, you can modify the magnifier so that it shows your data exactly how you want it. The magnifier is infinitely adjustable! To walk through some of the customizations of the magnifier, please follow the steps below.

1. Select Graph Magnifier 1 in the Object Manager.
2. In the Property Inspector, go to the Magnifier tab.
3. The Selected box option allows you to adjust the size and position of the magnifier boxes. There are two magnifier boxes:
   1. The Area selection box is the box that was created on the graph and contains the area to be magnified.
   2. The Zoomed area box is the box showing the zoomed in area.
   Set the Selected box to Area selection box.
   
   The Area selection box is the box on the plot to be magnified.
   The Zoomed area box contains the magnified portion of the plot.
4. On the area selection box, drag the ends of the box to change the size of the box. The zoomed area box will automatically update.
   
   With the Area selection box specified as the Selected box, you can change 
   the size of the area and position of the area to be magnified.
5. Now change the Selected box to the Zoomed area box. You can click and drag the zoomed area box anywhere on the screen. You can also drag the corners of the box to change the size of the magnified area.
   
   Change the size and location of the box displaying the magnified area.
6. The grid lines, tick marks and tick labels in the zoomed area box are independent from the graph and can be customized separately! This allows you to show the magnified area with more detail. To adjust the grid lines, make sure Graph Magnifier 1 is selected in the Object Manager and go to the Grid Lines tab in the Property Inspector.
7. You have the options to set the grid lines at major ticks, minor ticks and you have full control of the line properties. The first step is to specify which axis within the magnifier you want to adjust the grid lines for. The first line on theGrid Lines tab is Axes. Choose Y Axis 1 from the drop down menu.
8. Check the box next to At minor ticks. This will add grid lines to the minor ticks on Y Axis 1.
9. Open the Minor line properties section and choose a dashed line style with 20% Black for the color.
   
   Set the X and Y axis grid line properties for the zoomed area box by selecting
   the Graph Magnifier in the Object Manager and going to the Grid Lines tab in the Property Inspector.
10. To adjust the tick marks and tick spacing, go to the Tick Marks tab in the Property Inspector.
11. You can control which axes the tick mark adjustments will affect by changing the option on the first line, calledAxes. Set Axes to X Axis 1.
12. Open the Major ticks section and change the Date/time spacing to Every 6 Months. This will add more major ticks (and hence grid lines) to the X axis.
    
    Set the X and Y axis tick mark properties for the zoomed area box by selecting 
    the Graph Magnifier in the Object Manager and going to the Tick Marks tab in the Property Inspector.
13. The tick label properties for the zoomed area box are controlled on the Tick Labels tab of the Property Inspector.
14. You can specify which axes the tick label adjustments will affect by changing the option on the first line, calledAxes. Set Axes to X Axis 1.
15. Open the Major labels section and click <Click here to set label format>. That will open the Label Format dialog.
    1. On the Text Properties tab, change the Points to 14 and click Apply.
    2. On the Format tab, click the Background button.
    3. In the Line/Fill Properties dialog, specify a solid white background color and click OK.
    4. Click OK and the changes are made to the major tick labels on the X axis in the zoomed area box.
16. Now change Axes to Y Axis 1.
17. Repeat Step 16 above to increase the size and add the background color to the major tick labels on the Y axis.
18. Open the Minor labels section and check the check box next to Show labels. This will show labels on the minor ticks on the Y axis.
19. Click <Click here to set label format>. This will open the Label Format dialog.
    1. On the Text Properties tab, change the Points to 12 and click Apply.
    2. On the Format tab, click the Prefix button.
    3. In the Text Editor, enter a $ and click OK.
    4. Click the Background button.
    5. In the Line/Fill Properties dialog, specify a solid white background color and click OK.
    6. Click OK and the changes are made to the minor tick labels in the zoomed area box.
    
    Change the tick label properties for the magnifier on the Tick Labels tab of the Property Inspector.
20. Click on the Connector tab in the Property Inspector to specify the properties for the area connecting the area selection box and the zoomed area box.
21. Open the Line style section to specify the line style for the connector area. For example, you can change the line color to red, change the line style to a dashed line, and increase the line width.
22. Open the Fill style section to specify the fill style for the connector area. For example, you can change the pattern to a stippled pattern, and the foreground color to red.
    
    Change the properties of the area connecting the area selection box and the zoomed area box
    on the Connector tab in the Property Inspector.