# Main: Parameters

## Parameters

Parameters are fixed values that represent model inputs, fixed constants, or any other value that does not change. Parameters are not modified by the solver as it searches for a solution. As such, parameters do not contribute to the number of degrees of freedom (DOF).

Parameters are declared in the Parameters ... End Parameters section of the model file. The parameters may be defined in one section or in multiple declarations throughout the model. Parameter initialization is performed sequentially, from top to bottom. If a parameter does not have an initial value given, a default value of 1.0 is assigned. Parameters may also be a function of other parameters or variable initial conditions. These initial conditions are processed once as the first step after the model parsing.

### Example

  ! Example model that demonstrates parameter declarations Model example Parameters p0 ! no initial value provided - default = 1 p1 = 1.5 ! initializes to 1.5 p2 = 2 * p1 ! initializes to 3.0 p3 = exp(p2) * p1 ! initializes to exp(3.0) * 1.5 my_parameter = 1 ! initializes to 1.0 End Parameters End Model