The expression language itself is not a programming language. It does not have statements (sequencing of operations) nor does not support assignments... It supports just expressions. The result of evaluating an expression is an immutable (unchangable) token. If the result is an array, you cannot modify the elements of the array. You would have to create a new array.
FSM augments the expression language with assignments, but this makes sense because FSM has sequencing in its semantics.
If what you really want is a scripting capability, I suggest using the Python actor. Then you have a full programming language accessible rather than just an expression language. You can also use Matlab as a scripting language using the MatlabExpression actor.
Edward
At 12:55 PM 5/21/2004 +0200, Marija Surnaite wrote:
Hello,
we are three students from Aalborg University. We are using Ptolemy II for our study project. We encountered a few problems and would like to know if they are constraints of Ptolemy II or if we are just doing things in the wrong way.
1) In expression editor it is normal to assign a value to a variable. In an Expression actor we tried to assign a value to a parameter and it throws a parsing error.
In FSM model, assigning to a parameter (set action) works correctly.
2) We decided to model a block of RAM as an array (FSM model). We put a parameter named RAM and assigned initial values as following:
([1:1:length]*0.0).toArray()
We encountered a problem while assigning a value to a element of this array (set action "RAM[c]=value", where c is a parameter with integer value). The expression says that it requires <INTEGER> instead of c.
------------ Edward A. Lee, Professor 518 Cory Hall, UC Berkeley, Berkeley, CA 94720 phone: 510-642-0455, fax: 510-642-2739 [EMAIL PROTECTED], http://ptolemy.eecs.berkeley.edu/~eal
---------------------------------------------------------------------------- Posted to the ptolemy-hackers mailing list. Please send administrative mail for this list to: [EMAIL PROTECTED]
