Mathcad gives you control over many of the visual characteristics of scatter plots. These can be categorized in four groups:
• Viewing characteristics: the type of plot being displayed, the perspective or point of view from which you see the plot, and the presence or absence of borders, enclosing boxes, axes, and back planes.
• Color and line formatting: how the plot will mark points; how markers will be connected; and the format of any lines connecting markers.
• Axis formatting: whether to show tick marks or grid lines on each axis.
• Title characteristics: how the plot will display titles
To change any of these plot characteristics, start with the 3D Plot Format dialog box:
• Click on the plot to select it.
• Choose GraphesSl) Plot from the Format menu. Alternatively, double-click on the plot itself. Mathcad brings up the 3D Plot Format dialog box. The View Page of this dialog box is shown below. The remaining three tabs take you to three additional pages.
• If necessary, click the tab for the page you want to work with.
• Make the appropriate changes in the dialog box.
• To see the effect of your changes without closing the dialog box, click “Apply.”
• When you’re finished, close the dialog by clicking “OK.”
Changing your view of the scatter plot
The View page of the 3D Plot Format dialog box lets you modify the general presentation of your 3D scatter plot. To change your plot from a scatter plot to another type of 3D plot, click on the appropriate button in the Display As group. You can convert a scatter plot into a Surface Plot, Contour Plot, or a 3D Bar Chart. These plot types are fully discussed in the corresponding chapters in this User’s Guide.
When you view a scatter plot as a surface or contour plot or a 3D bar chart, Mathcad actually interpolates a surface that approximates your scatter data, using a 21 by 21 mesh by default. To change the density of this mesh, click on the Color & Lines tab and edit the number of rows and columns in the Interpolated Mesh group. If your data is not well approximated by a surface, Mathcad may be unable to compile a useful interpolation. If this occurs, Mathcad will signal this fact with a message in the status line.
As you view your scatter plot, you may not be able to perceive any patterns in your data. However, by examining the plot from another perspective, you may be able to isolate clusters of data. To change the perspective, or point of view, from which you see the scatter plot, change the numbers in the Rotation and Tilt text boxes. Use an
integer between 0 to 360 degrees. The effects of varying the rotation and tilt (as well as the scale) of a scatter plot.
• Increasing the rotation turns the plot clockwise.
• Tilt controls whether you see the data edge on or whether you look down from directly overhead.
To add or remove a border around the scatter plot region, click on Show Border. The border is a two-dimensional frame around the scatter plot region. To enclose the plot and the axes within a three-dimensional bounding box, click on Show Box in the Frames group to add a check. To show the xy, XZ, and yz back planes:
• Click on Show in the Back Planes group.
• To color the surface of the back planes, click on “Fill Color.”
• To outline the edges of the back planes in a particular color, click on “Edge Color.”
A scatter plot with a border around it and with back planes showing together with the same plot enclosed within a box without showing back planes.