Each XY plot node contains X Type and Y Type sub-nodes to specify what should be plotted along the X and Y axes of the graph, respectively. To select a solution variable to be plotted along one of the axes, select the corresponding node (either X Type or Y Type) and select Scalar for the Type property. This will activate the Scalar node, which has its own properties.
This node defines the data for the axis of this node's parent to come from a scalar field function. It is only visible if the Type property of the parent node is set to Scalar.
To specify the solution variable, select the Scalar sub-node and use the Scalar property.
