# Experimental data as time-dependent input in COPASI

Implementing systems with forcing functions as exogenous input (COPASI .cps file).

Experimental data in lookup table, implemented as a time-dependent, piecewise defined function using events.

Lookup table with experimental time-course data:

time [min] | input data |

0 | 0.04339 |

15 | 0.14100 |

30 | 0.41646 |

45 | 0.51149 |

60 | 0.41065 |

90 | 0.25279 |

120 | 0.14389 |

180 | 0.07045 |

240 | 0.04854 |

Species:

- I: exogenous input
- x: model variable

- degradation of x (mass action kinetics)
- Ra: rate of appearance of x based on the input I

- parameter p1 = 0.1

Create Rate Law for rate of appearance reaction as product of a kinetic parameter (ka) and a modifier (input data, between double quotes to form one single string from the two words):

Rate of appearance reaction Ra, with input I as modifier:

Model reactions:

Resulting differential equation model:

Create events to implement piecewise constant, time-dependent parameter. User-defined functions with logical operators.

Repeat this for all datapoints in the lookup table. Overview of all 9 events:

Simulation window in COPASI:

Simulation results:

- List of files: experimental data as time-dependent input.cps
- COPASI website: http://copasi.org