algorithm assigning an array fails during transformation

[Lennart Ochel]

The following model fails during index reduction:

model Unnamed
  Real a[3];
algorithm
  a[1] := 1;
end Unnamed;

Error message:

Simulation failed for model: Unnamed
Error: Model is structurally singular, error found sorting equations
 1: algorithm
  a[1] := 1.0;
;
 for variables
 a[1](3), a[3](1), a[2](2)
Error: Internal error Transformation Module PFPlusExt index Reduction Method Pantelites failed!

If the model gets extended with a state the translation fails due to unreferenced variables a[2] and a[3]. This is wrong because a[2] and a[3] are referenced in the algorithm (implicit).

model Unnamed
  Real a[3];
  Real x;
equation
  der(x) = 0;
algorithm
  a[1] := 1;
end Unnamed;

Error message:

Simulation failed for model: Unnamed
[<interactive>:3:3-3:12:writable] Error: Variable a[2] is not referenced in any equation (possibly after symbolic manipulations).

[Lennart Ochel]

I will fix the second part of this ticket. Maybe there is also someone who will look into the first part.

[Martin Sjölund]

Postponed until 1.9.1

[Martin Sjölund]

This ticket was not closed for 1.9.1, which has now been released. It was batch modified for milestone 1.9.2 (but maybe an empty milestone was more appropriate; feel free to change it).

[Martin Sjölund]

Milestone changed to 1.9.3 since 1.9.2 was released.

[Martin Sjölund]

Moved to new milestone 1.9.4

[Martin Sjölund]

Milestone pushed to 1.9.5

[Martin Sjölund]

Milestone renamed

[Martin Sjölund]

Ticket retargeted after milestone closed

[Martin Sjölund]

Milestone moved to 1.12.0 due to 1.11.0 already being released.

[Francesco Casella]

The problem is still present as of v1.13.0-dev-188-g2c5818d. Section 1.11.2 of the spec says:

If at least one element of an array appears on the left hand side of the assignment operator, then the complete array is initialized in this algorithm section

so the statement a[1]:=10; should also imply a[2]:=0; a[3]:=0;

[Francesco Casella]

The milestone of this ticket has been reassigned to "Future".

If you think the issue is still valid and relevant for you, please select milestone 1.13.0 for back-end, code generation and run-time issues, or 2.0.0 for front-end issues.

If you are aware that the problem is no longer present, please select the milestone corresponding to the version of OMC you used to check that, and set the status to "worksforme".

In both cases, a short informative comment would be welcome.