A simple demonstration of connecting APSIM to optimisation frameworks
The APSIM Initiative Reference Panel has provided two examples for connecting APSIM to optimisation techniques.
The first bespoke example shows the use of the R XML library to manipulate apsim input files, simple data importation, and calculation of error statistics. The trivial example modifies a single soil parameter (CN2 of bare soil). There are other optimisation libraries in R that can exploit available hardware (parallel evaluation) and software (multi-objective optimisation) features of the problem under examination.
The second example follows the simple worked example in the PEST documentation. The problem description follows a template driven approach, where string patterns are searched for and replaced with the specific parameter value(s) under examination. It likewise examines a single apsim soil parameter. PEST also has facilities for parallel evaluation, though requires small effort to write predicted data into a form that can be read by the optimising harness. APSIMs flexible manager and reporting components make this process quite easy.