The Expression Builder Wizard (Figure 1) gathers many functions
related to adding expressions on a Node Table. It consists of the Options panel, The Expression
Builder Panel and the Table Panel. The main
purpose of this wizard is to make it easier to build an expression by
assisting the user in selecting the correct type of expression the
current node supports, selecting the correct type of parent nodes to be
used in an expression and dividing the whole process into steps that
allows him to concentrate on building one simple expression at a time
without losing the overview of the complete expression.
Figure 1. Expression Builder
Wizard
To build an expression, select one of the
felts in the expression table where it shows "Undefined" (Figure 1).
The Expression Builder Panel
(Figure 1a) that is relevant for the type of the current node is now
visible. Select the desired function category and then a function from
the Function Name combo box to view the appropriate argument fields.
Type expressions in the argument fields or press the "f(x)" button next
to them to build an expression for the corresponding field. To insert a
parent, right click and select from the list that appears.
The Option Panel (Figure 2) offers functionalities that are also
available in the Node Table Frame menu.
Figure 2. The Options Panel.
The Add/Remove model node combo boxes as implied, allows the user to add or remove parent nodes to the expression table .The Expression Builder Panel assists the user in building
expressions by providing a
simple user interface for selecting a function or an operator and
specifying its
arguments.
The combo boxes at the top of the panel ("Function category" and "Function Name"),
show the functions available (the actual set of functions depends on
the type of the
node associated with the current node table). Selecting a "Function Category" populates the "Function Name" combo box with the
corresponding functions allowing the user to select. Figure 3a shows
the function categories associated with a "Numbered" node. The functions are
organized
in a number of categories to make it faster to find a particular
function.