On entry: values to be used to control step size choice during integration. If any
${\mathbf{CON}}\left(i\right)=0.0$ on entry, it is replaced by its default value described below. In most cases this is the recommended setting.
${\mathbf{CON}}\left(1\right)$, ${\mathbf{CON}}\left(2\right)$, and ${\mathbf{CON}}\left(3\right)$ are factors used to bound step size changes. If the current step size $h$ fails, then the modulus of the next step size is bounded by ${\mathbf{CON}}\left(1\right)\times \left|h\right|$. The default value of ${\mathbf{CON}}\left(1\right)$ is $2.0$. 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 $h$, then the modulus of the step size on the second step is bounded by ${\mathbf{CON}}\left(3\right)\times \left|h\right|$. At any other stage in the integration, if the current step size is $h$, then the modulus of the next step size is bounded by ${\mathbf{CON}}\left(2\right)\times \left|h\right|$. The default values are $10.0$ for ${\mathbf{CON}}\left(2\right)$ and $1000.0$ for ${\mathbf{CON}}\left(3\right)$.
Constraints:
These constraints must be satisfied after any zero values have been replaced by default values.
- $0.0<{\mathbf{CON}}\left(1\right)<{\mathbf{CON}}\left(2\right)<{\mathbf{CON}}\left(3\right)$;
- ${\mathbf{CON}}\left(2\right)>1.0$;
- ${\mathbf{CON}}\left(3\right)>1.0$.