Custom Function  (3D XYZ Graphs)

These options are available in the Custom Function dialog box and via the Graph Options dialog box.

Use these options to modify or delete an existing custom function or add a new one to the current plot. Note that unlike in 2D Custom Functions, only one 3D function (surface) can be displayed at a time.

Function/Add new function/Delete

A drop-down list of functions in the current graph is displayed in the Function field. To edit an existing plot, select the plot number and use the options below. If no functions are available or if you want to create a new function, click the Add new function button. To delete an existing function, specify the function number in the Function field and click the Delete button.

Display contour

Select the Display contour check box to request that the contour lines (projection of the surface onto the horizontal plane) be shown for this function.

Display surface (only one)

Select the Display surface check box to display the surface specified by the current custom function. Note that only one surface at a time can be displayed in a 3D graph.

Surface specs

Click the Surface specs button to display the Surface Specifications dialog box, which provides full control of the colors, shading, and other surface and contour line options used in 3D and 2D contour (of 3D) plots.

Z(x,y) =

Type in the function you want to plot in the Z(x,y) = box. Note that if you have selected the Function guide check box, a menu with possible characters or functions will be displayed as you type. You can choose from any item on the menu, or type the function yourself. If you want to save this function for later use, you must add it to the function field in the Function Name Manager. It will not be automatically added for you.

Function guide

Select the Function guide check box to display a list of possible functions and related properties when you enter a custom function into the Z(x,y) = box.

Add to list

Click the Add to list button to create a function that can be saved and reused at a later time. The Custom Function Name dialog box will be displayed, in which you can specify a name for the function. The function can then be selected from the Function Name Manager and edited (see Function List below).

Function list

Click the Function list button to display the Function Name Manager, which is used to create a new function and to edit, rename, or delete an existing function.

Use event handler calculations

When a custom function handler is attached to the graph, you can use either the custom function calculations as defined in the event handler or enter the custom function in the Z(x,y) box. To use the custom function calculations, select the Use event handler calculations check box. The Z(x,y) box will be dimmed and the custom calculations will be applied. When this check box is cleared, you must enter the custom function in the edit box. Note that this option is only enabled when a custom function handler is attached to the graph. For more information on creating custom functions, see the SVB example on Creating User-defined Custom Functions.

Range X, Range Y

Use the Range X, and Range Y groups to specify the ranges (i.e., Minimum and Maximum values) for the custom function in the two horizontal (x and y) dimensions. For each axis, you can either base the range of values on the scaling of the current axis (select from axis for both the minimum and maximum values), or you can specify a custom range (select custom for both values). Note that, for each axis, you can also select from axis for the Minimum value and custom range for the Maximum value, or vice versa, i.e., custom for the Minimum value, and from axis for the Maximum value. If you choose a custom range, specify the Minimum and/or Maximum value in the appropriate Value field.

Style

As all other features and aspects of graphs, the specifications for the custom fit surface can be saved in a Graphics Style using the Style box. In this case, this style will primarily contain any customizations you may have made in the Surface Specifications dialog box. To view a menu of options related to styles (Save, Save As, Revert to unmodified, etc.), click the button to the right of this box. See Graphics Styles for additional details.