Working with equations

Equations are the mathematical basis for simulating the behaviour of a
model. Before its equation is entered, a model element is displayed in
red. It is not possible to run the simulation whilst any model elements
are still red. Simile has an equation language that allows great power and
flexibility in specifying expressions, reading data from tables, or
sketching semi-quantitative relationships by hand. For more information,
see the Introduction to equations.

How to enter equations

There are two ways to enter equations for calculating model element
values. Either use:

• the Equation bar, for simple expressions; or
• the Equation dialogue window, for more
  complex expressions.

How to write equations

The following topics provide detailed reference information on the parts
that make up a complex expression, and on the mathematical functions
available, both built-in and user-supplied. See:

• the components of an equation;
• functions; generally, and
  specifically:
• • built-in functions; or
  • user-supplied functions

Working with variables and data types

Further information on variables and data types useful in understanding
Simile.

• Arrays and lists
• Dimensions
• Parameters for fixed or variable
  quantities
• Physical units
• Enumerated types
• Local names within equations for other
  variables

In: Contents