id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
3081	Inverse solving of algorithms	Lennart Ochel	Lennart Ochel	"There is one model in the test suite that cannot get initialized with the symbolic initialization, since there is no support for inverse solving of algorithms:
{{{
testsuite/openmodelica/modelicaML/watchdog.mos
}}}

The following model can be used as simplified test case:
{{{#!mo
model A
  Real x, y, z;
  Real der_x, der_y, der_z;
equation
  der_x = der(x) + 1;
  der_y = der(y) + 2;
  der_z = der(z) + 3;
initial equation
  der(x) = 0;
  der(y) = 0.5;
  der(z) = 0;
algorithm
  der_x := x;
  der_y := der_x + y;
  der_z := der_y + z;
end A;
}}}

The output is the following:
{{{
Error: Internal error Inverse Algorithm needs to be solved for {y,z,x} in 
algorithm
  der_x := x;
  der_y := der_x + y;
  der_z := der_y + z;
This has not been implemented yet.
Error: Internal error function createSingleAlgorithmCode failed!
Error: Internal error function createOdeSystem failed for component Algorithm 4 {7, 5, 9}
Error: Internal error function createEquationsForSystem1 failed for component Algorithm 4 {7, 5, 9}
Warning: No system for the symbolic initialization was generated. A method using numerical algorithms will be used instead.
}}}
"	defect	closed	high	1.9.4	Backend	trunk	fixed