: values to be used to control step size choice during integration. If any
on entry, it is replaced by its default value described below. In most cases this is the recommended setting.
, , and are factors used to bound step size changes. If the current step size fails, then the modulus of the next step size is bounded by . The default value of is . Note that the new step size may be used with a method of different order to the failed step. If the initial step size is , then the modulus of the step size on the second step is bounded by . At any other stage in the integration, if the current step size is , then the modulus of the next step size is bounded by . The default values are for and for .
These constraints must be satisfied after any zero values have been replaced by default values.