id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
3116	Make warning/error message from the nonlinear solver more informative	Francesco Casella	somebody	"When simulating the {{{ThermoPower.Examples.CISE.CISESim120501}}} example using OMEdit, a lot of red warning messages pop up, saying:

- Matrix singular!

- under-determined linear system not solvable!

- Warning: maximal number of iteration reached but no root found

These messages succeed in conveying the message that something goes wrong with the solver and scaring off the user.

However, when it comes to try to understand the cause of the problem and fix it, these messages leave the poor user utterly clueless.

I would definitely suggest to make these messages a bit more informative, e.g. by adding the number of the system that becomes singular, possibly with a direct link to the declarative debugger (Debug more!), or writing ''which'' matrix exactly has singularity problems and how can one understand why it is so (nullspace, rank, etc). This will give users a chance of understanding the cause of the problem and hopefully fix it. 

Otherwise, troubleshooting the model would require supernatural divination abilities that few people (if any) in the community possess :)"	defect	new	high		Backend	trunk