2 | | To simulate chemical or biological process in Diana the Initial Value Problem should be solved at first. A guess for initial conditions can be set in model file. [[BR]] Standard {{{ IDACalcIC() }}} method of Sundials package can calculate consistent initial conditions for homogeneous differential algebraic equations systems of the type |
3 | | |
4 | | {{{ |
5 | | #!html |
6 | | <table border="0" width="50%" align="center"> |
7 | | <tr> |
8 | | <td align = "center" fontsize ="50%" width="90%"> |
9 | | dx<sub>1</sub>/dt = f<sub>1</sub>(x<sub>1</sub>, x<sub>2</sub>, ..., x<sub>n</sub>, t)<br> |
10 | | dx<sub>2</sub>/dt = f<sub>2</sub>(x<sub>1</sub>, x<sub>2</sub>, ..., x<sub>n</sub>, t)<br> |
11 | | ... <br> |
12 | | dx<sub>n</sub>/dt = f<sub>n</sub>(x<sub>1</sub>, x<sub>2</sub>, ..., x<sub>n</sub>, t) |
13 | | </td> |
14 | | <td align="center">(1) |
15 | | </td> |
16 | | </tr> |
17 | | </table> |
18 | | }}} |
19 | | |
20 | | But in case of non-homogeneous differential algebraic equations systems of the type |
21 | | |
22 | | {{{ |
23 | | #!html |
24 | | <table border="0" width="50%" align="center"> |
25 | | <tr> |
26 | | <td align = "center" fontsize ="50%" width="90%"> |
27 | | F<sub>1</sub>(dx<sub>1</sub>/dt, dx<sub>2</sub>/dt, ..., dx<sub>n</sub>/dt) = f<sub>1</sub>(x<sub>1</sub>, x<sub>2</sub>, ..., x<sub>n</sub>, t)<br> |
28 | | F<sub>2</sub>(dx<sub>1</sub>/dt, dx<sub>2</sub>/dt, ..., dx<sub>n</sub>/dt) = f<sub>2</sub>(x<sub>1</sub>, x<sub>2</sub>, ..., x<sub>n</sub>, t)<br> |
29 | | ... <br> |
30 | | F<sub>n</sub>(dx<sub>1</sub>/dt, dx<sub>2</sub>/dt, ..., dx<sub>n</sub>/dt) = f<sub>n</sub>(x<sub>1</sub>, x<sub>2</sub>, ..., x<sub>n</sub>, t) |
31 | | </td> |
32 | | <td align="center">(2) |
33 | | </td> |
34 | | </tr> |
35 | | </table> |
36 | | }}} |
37 | | |
38 | | {{{IDACalcIC()}}} generates the exception |
| 2 | To simulate chemical or biological process in Diana the Initial Value Problem should be solved at first. A guess for initial conditions can be set in model file. [[BR]] Standard {{{ IDACalcIC() }}} method of Sundials package can calculate consistent initial conditions for differential algebraic equations systems, [[BR]]whose state vector can be separated into a dynamic part and algebraic part. If this is not possible {{{IDACalcIC()}}} generates the exception |