HS.solution

Function describing two exponential decline functions with a break point
between them.

Calculation routines based on the FOCUS Kinetics Report (2006,
2014). Includes a function for conveniently defining differential equation
models, model solution based on eigenvalues if possible or using numerical
solvers. If a C compiler (on windows: 'Rtools') is installed, differential
equation models are solved using automatically generated C functions.
Heteroscedasticity can be taken into account using variance by variable or
two-component error models as described by Ranke and Meinecke (2018)
<doi:10.3390/environments6120124>. Hierarchical degradation models can
be fitted using nonlinear mixed-effects model packages as a back end as
described by Ranke et al. (2021) <doi:10.3390/environments8080071>. Please
note that no warranty is implied for correctness of results or fitness for a
particular purpose.

Johannes Ranke

mkin

Kinetic Evaluation of Chemical Degradation Data

Katrin Lindenberger

René Lehmann

Eurofins Regulatory AG 

HS.solution function

<dl><dt>t</dt>
<dd>Time.</dd>
<dt>parent_0</dt>
<dd>Starting value for the response variable at time zero.</dd>
<dt>k1</dt>
<dd>First kinetic constant.</dd>
<dt>k2</dt>
<dd>Second kinetic constant.</dd>
<dt>tb</dt>
<dd>Break point. Before this time, exponential decline according to
<code>k1</code> is calculated, after this time, exponential decline proceeds
according to <code>k2</code>.</dd></dl>

Arguments

Hockey-Stick kinetics — HS.solution

<dl>

<dt>t</dt>
<dd>Time.</dd>


<dt>parent_0</dt>
<dd>Starting value for the response variable at time zero.</dd>


<dt>k1</dt>
<dd>First kinetic constant.</dd>


<dt>k2</dt>
<dd>Second kinetic constant.</dd>


<dt>tb</dt>
<dd>Break point. Before this time, exponential decline according to
<code>k1</code> is calculated, after this time, exponential decline proceeds
according to <code>k2</code>.</dd>

</dl>

HS.solution: Hockey-Stick kinetics

Description

Usage

Value

Arguments

References

See Also

Examples