#1624 differentation forced to 0 if wired up

[JAMES SAULNIER]

An error I can't figure out.
Dimensional analysis passes.
I do see a red circle on differentiation operator.

Bookmarked area is "CG equations"
If variable j is not wired to Delta CG then j increments.
if j is wired to Delta CG then j remains at 0.

[JAMES SAULNIER]

screen shot

[High Performance Coder]

The red circle is a bug - there is no actual error being reported. I have fixed the code to clear the error condition causing that. But that is not the cause of your problem.

The reason why \Delta CG is 0 is that CG is zero for all time, and if you follow back the chain of definitions, you will see that one of the factors making up CG is \Delta CG, so it is defined in terms of itself. If the derivative is zero, then CG is a constant, and its derivative will be zero.

I found the "Find definition" feature useful for tracing back the logic. I advanced the model several steps, and then looked at why certain variables were zero.