The graphical EXPERT environment (XP) is  friendly, graphics-based environment utilised by a range of software developed by Innovyze. It encompasses data entry, run-time graphics, and post-processing of results in graphical form. 

The user is given continual guidance and assistance during data entry. For parameters that are difficult to estimate the user may be advised of literature to aid in selecting a value, or an explanation of a parameter and some proposed values may be shown on the screen through the use of on-line help. If there are other ways to pick the value typically, if the parameter is a function of other variables, the equation is shown to the user.

The user interface is intelligent and offers expert system capabilities based on the knowledge of the software developers and experienced users. For example, as various graphical elements are connected to form a network, EXPERT filters the user's actions so that a network that is beyond the scope of the model is not created. The general philosophy is to trap any data problems at the highest possible level - at the point the users create the data.

In addition to the well-known and accepted benefits of input and output graphics the EXPERT environment provides the user with expert data checking facilities. In the case of XP-RatHGL these checks include:

Network Manipulation

Knowledge based data filtering prevents the creation of an illegal network or modifications that would result in an illegal network. The network is checked to meet the following constraints:

  • Number of incoming links not greater than 10. 

  • Number of outgoing links not greater than 1.
  • Number of outgoing diversions not greater than 1.
  • Maximum number of all incoming links including diversions not greater than 10.
  • Maximum number of all outgoing links including diversions not greater than 2.
  • Loops are not allowed.

Data Type

Data entered via text items is checked against the data type expected for that item. If a number is expected then the text string entered is interpreted to see it follows the rules for numerical strings. For example, if an integer (whole number) is expected, then invalid characters such as non-digits, decimal points etc, are trapped and the data is not accepted.

Pure text strings or comments are accepted as entered.

The syntax for numerical strings follows the usual rules. Larger-magnitude numbers can be entered via exponential notation.

EXPERT indicates floating-point numerical items by adding a decimal point if you haven't already done so.

Data Range Checking

As data is entered it is filtered on two levels:

  • Data is checked to ensure it is within a "reasonable" range. eg. Subcatchment slope has a reasonable range of 0.5 to 30 percent. If data is outside the reasonable range a warning message is issued with the reasonable range indicated but the data is accepted.
  • Data is checked to ensure it is within an absolute limit. eg. Subcatchment slope cannot be <0. If data is outside the absolute range an error message is issued with the valid range indicated and the data not accepted. Execution cannot continue unless a valid value is entered or "Cancel" is selected.

Relational Consistency Checking

After all the data has been entered and the user attempts to solve the networks the inter-relationship of all data is checked for consistency, again at two levels:

  • Warning messages are generated for data outside reasonable constraints, but the network can still be solved, and
  • Error messages are generated for data outside the absolute range and the network can not be solved until these are corrected.

The following list includes some of the relational checks made:

  • Nodes at top of branches must have catchment data. 
  • Warning level checks for reasonable pipe slopes. The reasonable range is set to between 0.3% and 30%.
  • Relative inlet/outlet invert levels at the outlet node. Invert levels should decrease downstream.
  • Relative inlet/outlet pipe diameter warning level checks at node. Pipe sizes should increase downstream.
  • Maximum water surface levels must decrease downstream. This is trapped as an error.