### 29.1.2. Plot

The Plot tab is used to plot the selected expression against one variable. CFX-Pre automatically finds the variables associated with an expression, even if the expression depends on another expression.

For example, when previewing the expression `halfRadius`, defined as `0.5*radius`, where `radius` is an expression that depends on the variables `x` and `y`, CFX-Pre presents `x` and y as the variables upon which `halfRadius` depends.

1. Set up an expression in the Definition tab, or open an existing expression. Click the Plot tab.

2. Under Number of Points, set the number of sample data points for the plot.

   Sample points are connected by line segments to approximate the functional relationship.

3. Under Expression Variables, select the independent variable.

4. Set the range for the independent variable.

5. Set Fixed Value for all of the remaining independent variables.

6. Click Plot Expression to view the resulting chart.

   The Plot Expression button changes to Define Plot. This can be clicked after viewing the plot in order to make adjustments to the plot specification.

Release 18.2 - © ANSYS, Inc. All rights reserved.