Struct rgsl::types::ordinary_differential_equations::ODEiv2Step

pub struct ODEiv2Step { /* fields omitted */ }

Implementations

impl ODEiv2Step

pub fn new(t: ODEiv2StepType, dim: usize) -> Option<ODEiv2Step>

This function returns a pointer to a newly allocated instance of a stepping function of type T for a system of dim dimensions. Please note that if you use a stepper method that requires access to a driver object, it is advisable to use a driver allocation method, which automatically allocates a stepper, too.

pub fn reset(&mut self) -> Value

This function resets the stepping function s. It should be used whenever the next use of s will not be a continuation of a previous step.

pub fn name(&self) -> Option<String>

This function returns a pointer to the name of the stepping function. For example,

println!("step method is '{}'", s.name().unwrap());

would print something like step method is ‘rkf45’.

pub fn order(&self) -> u32

This function returns the order of the stepping function on the previous step. The order can vary if the stepping function itself is adaptive.

pub fn set_driver(&mut self, d: &ODEiv2Driver<'_>) -> Value

This function sets a pointer of the driver object d for stepper s, to allow the stepper to access control (and evolve) object through the driver object. This is a requirement for some steppers, to get the desired error level for internal iteration of stepper. Allocation of a driver object calls this function automatically.

pub fn apply(
    &mut self,
    t: f64,
    h: f64,
    y: &mut [f64],
    yerr: &mut [f64],
    dydt_in: &[f64],
    dydt_out: &mut [f64],
    sys: &mut ODEiv2System<'_>
) -> Value

This function applies the stepping function s to the system of equations defined by sys, using the step-size h to advance the system from time t and state y to time t+h. The new state of the system is stored in y on output, with an estimate of the absolute error in each component stored in yerr. If the argument dydt_in is not null it should point an array containing the derivatives for the system at time t on input. This is optional as the derivatives will be computed internally if they are not provided, but allows the reuse of existing derivative information. On output the new derivatives of the system at time t+h will be stored in dydt_out if it is not null.

The stepping function returns Value::Failure if it is unable to compute the requested step. Also, if the user-supplied functions defined in the system sys return a status other than ::Value::Success the step will be aborted. In that case, the elements of y will be restored to their pre-step values and the error code from the user-supplied function will be returned. Failure may be due to a singularity in the system or too large step-size h. In that case the step should be attempted again with a smaller step-size, e.g. h/2.

If the driver object is not appropriately set via gsl_odeiv2_step_set_driver for those steppers that need it, the stepping function returns ::Fault. If the user-supplied functions defined in the system sys returns Value::BadFunc, the function returns immediately with the same return code. In this case the user must call gsl_odeiv2_step_reset before calling this function again.

Trait Implementations

impl Drop for ODEiv2Step

fn drop(&mut self)

Executes the destructor for this type.