View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000549 | ascend | integrator | public | 2012-04-20 06:53 | 2012-04-24 08:04 |
| Reporter | john | ||||
| Assigned To | |||||
| Priority | normal | Severity | feature | Reproducibility | always |
| Status | new | Resolution | open | ||
| Platform | Linux | OS | Ubuntu | OS Version | 12.04 LTS |
| Product Version | 0.9.8 | ||||
| Target Version | 1.0 | Fixed in Version | |||
| Summary | 0000549: IDA can't integrate constants | ||||
| Description | There is an important degenerate case that we can't currently support with the IDA integrator, and possibly other integrators too. A model that simply aims to calculate integ(1*t, t) from 0 to 10 fails, because we can't integrate a constant (1). The problem lies in the integration process, which doesn't add the integral variable unless it's explicitly present in the model equations. | ||||
| Steps To Reproduce | In current trunk (changeset 4096) attempt to load the file models/test/ida/integ1.a4c. After attempting to start the integration, ASCEND crashes with ascend/integrator/integrator.c:283 (integrator_set_engine): Setting engine... ascend/integrator/integrator.c:508 (integrator_analyse): Analysing integration system... ascend/integrator/integrator.c:448 (integrator_find_indep_var): sys->x already set ascend/integrator/integrator.c:525 (integrator_analyse): got 0 from integrator_find_indep_var solvers/ida/idaanalyse.c:521 (integrator_ida_analyse): System contains a total of 0 bnds and 2 rels solvers/ida/idaanalyse.c:524 (integrator_ida_analyse): Currently 2 rels active solvers/ida/idaanalyse.c:530 (integrator_ida_analyse): After analysing WHENs, there are 2 rels active solvers/ida/idaanalyse.c:129 (integrator_ida_check_vars): 'y' has a derivative present, so needs to be included in the system solvers/ida/idaanalyse.c:130 (integrator_ida_check_vars): That var is active solvers/ida/idaanalyse.c:214 (integrator_ida_flag_rels): Found 1 differential equations (so 1 algebraic) PROGRAM FATAL ERROR: solvers/ida/idaanalyse.c:248:integrator_ida_sort_rels_and_vars: Assertion failed: ny1 == integ->n_y | ||||
| Tags | No tags attached. | ||||
