Matlab script

The calculations performed by the unit operations are defined by Matlab script. You can enter the script by editing the unit operation, and select Script on the Matlab tab.

The Matlab script is run in a fresh Matlab environment, in which useful global variables and functions are predefined. The script should:

obtain feed data using getFeedProp
obtain the values of input parameters - if any - using getParameter
calculate the unit operation's result by user calculations that can use the available functions
set the properties of each product using setProduct
set the values of output parameters - if any - using setParameter
set the content of user define reports - if any - using setReport

DOs and DON'Ts

do set all outlet ports using setProduct
do use try / catch for error trapping

Don't

don't write to files named "calc.m", "unitCalc.m", "runUnit.m", "out", "report.txt" or "unit.xml"
don't redefine functions or global variables
don't change the working directory in the user script
don't use exit or quit
don't use pause or any other function that forces keyboard interaction
don't close or kill the Matlab application that runs as OLE server
don't use other applications that use Matlab as an OLE server when using Matlab based unit operations

Testing

To test your Matlab input, make sure the ports are connected. Then, while writing the script, click the Test button for feedback.

Editing

You can edit the script in the text box provided on the Script tab, or you can click the Edit button. The Edit button will open the external editor. The Matlab Unit Operation dialog will block until this editor has been closed.

The default editor is medit.exe in the Matlab program folder (or notepad.exe if medit.exe cannot be found). You can select a different text editor by holding down Ctrl while clicking on the Edit button.

Example

Example script for a simple adiabatic mixer with two feeds and one product:

f1=getFeedProp(1,'flow')
f2=getFeedProp(2,'flow')
h1=getFeedProp(1,'enthalpy')
h2=getFeedProp(2,'enthalpy')
p1=getFeedProp(1,'pressure')
p2=getFeedProp(2,'pressure')
p=min(p1,p2)
f=f1+f2
h=(h1*f1+h2*f2)/f
totF=sum(f)
setProduct(1,totF,f/totF,'pressure',p,'enthalpy',h)

(This particular script does not take into account that the total flow may be zero; it will fail in this case).