The Axes page of the 3D Plot Format dialog box, shown below, lets you modify the format of the x- and y-axis of your plot. Each axis is described by its own set of,check boxes and text boxes.
Mathcad generates grid lines on the plot at the same positions as the tick marks. To choose between seeing tick marks or grid lines on a selected axis, use the Grid Lines check box. When Grid Lines is checked, Mathcad adds grid lines to the plot.The same contour plot with and without grid lines.
To add or remove numbers for the tick marks on an axis, use the Numbered check box for that axis. The plot with grid lines in Figure 23-5 doesn’t have numbers on the axes while the plot without grid lines does have them.
You can have Mathcad automatically select the number of grid intervals on an axis or you can specify the number yourself. Grid intervals are the spaces between tick marks or grid lines.
• To have Mathcad select the number of grid intervals, use the Auto Grid check box. When Auto Grid is checked, Mathcad will automatically select the number of grid intervals on the specified axis.
• To specify the number of grid intervals on an axis yourself, enter an integer from 1 to 99 in the No. of Grids text box. This text box is only available when Auto Grid is unchecked.
To set limits on the maximum or minimum values of the x- or y-axis, enter the limit in the Max. Val. or Min. Val. text box. However, since the surface of the plot is stored as rows and columns in a matrix, these numbers have no significance as coordinates. They affect the display only. By default, Min and Max are set to -1 and respectively.
Labeling the contour plot
The Title page of the 3D Plot Format dialog box, shown below, lets you add and modify labels on your contour plot.
To add or edit a title for your contour plot:
• Type the title for your plot into the Title text box.
• To display the title, click on Show Title to insert a check. To conceal the title without deleting it, click on Show Title to remove the check.
• To position the title, click on either the Above or Below button. Mathcad places the title either directly above or below your plot.
• Click “OK” or “Close” to close the dialog box when you have finished. To change the title’s text or position, edit the information in the Title group as appropriate. To delete the title, highlight it in the text box and press [Del]. How Mathcad positions a title on a 3D plot.