Numerical integration: comparison ode45 versus ode15s in stiff/ non-stiff ODEs (Matlab example)

Antonio Sala, UPV

Difficulty: ** ,       Relevance: ,      Duration: 10:46

*Enlace a Spanish version

Summary:

The present video discusses numerical integration of ordinary differential equations (in first-order state-space representation), comparing performance of ode45 versus ode15s in two different settings:

• In cases where all time constants are similar (non-stiff ODE); in such cases, ode45 performs faster than ode15s

• In stiff ODEs, where there are very different time constants; in these latter cases, ode15s is the solver which performs significantly faster.

In the video [tubulFEsim1EN] a tubular heater with transport delay is simulated; in that case, ode15s also rendered faster than ode45 but, as shown in this material, each case needs to be individually studied in search for the best compromise between simulation accuracy and memory/time footprint.

*Link to my [ whole collection] of videos in English. Link to larger [ Colección completa] in Spanish.