pl1024 / dympy

Module to command Dymola from python

dympy

A tool to communicate with Dymola from python on Windows dympy communicates with dymola through DDE (Dynamic Data Exchange). After a connection with an open Dymola window is established, commands can be sent as if they were typed in the Dymola command line. Several usefull commands (opening models, setting model parameters, compiling, writing a dsin.txt file, simulating, and loading results,...) have been predefined for ease of use.

Check the example below for a quickstart or the docstrings for a more complete guide.

Installation

requires:

• numpy
• scipy
• pywin32 available here.

To install download the latest release., unpack, cd to the unpacked folder and run:

python setup.py install

Example

First initialize the Dymola connection. It is good practice to clear all open models from Dymola after initialization to avoid redefinition conflicts, however this is not necessary:

dymola = dympy.Dymola()
dymola.clear()

Next we'll open a model and compile it:

dymola.openModel('example.mo')
dymola.compile('example')

Parameters can be changed using the set_parameters method. The method takes a dictionary with name, value pairs as input. Inputs can be written to a dsu.txt file using the write_dsu method. The method again takes a dictionary with name, value pairs as input, time must always be one of the inputs:

dymola.set_parameters({'C_in.C':5e6,'C_em.C':10e6,'UA_em_in.G':1600,'UA_in_amb.G':200})
dymola.set_parameters({'C_em.T':300})
dymola.write_dsu({'time':[0,43200,86400],'Q_flow_hp':[1000,5000,2000],'T_amb':[273.15,278.15,273.15]})

The simulation can now be started within a certain time range:

dymola.simulate(StopTime=86400)

After the simulation is finished you can load the results as a dictionary using get_result(). The result is a dictionary with the variable names in dot notation as keys:

res = dymola.get_result()
print(res.keys())

There is also a get_res method implemented which will return all result keys which are children of the supplied argument key. If the argument has no children it's value is returned:

dymola.get_res('UA_em_in')