Poseidon CCR dives: Nitrogen loading - the solution

[Willem Ferguson]

Robert,
I have finally seen the light. I apologise for a swathe of confusing 
messages today. I have diagnosed the problem and it should be pretty 
easy to fix. What I should have seen in two minutes has taken me several 
hours of work.

Your patch causes all references to cylinder 0 to be returned as a 
reference to cylinder 1. So, in principle, cylinder 0 cannot be 
referenced. The logic that does the cylinder pressure calculations are 
critically dependent on being able to reference cylinder 0 because of 
the required interpolation structures that must have an index of 0. So, 
what happens at the moment is that the oxygen cylinder pressures are 
overwritten over the diluent pressures because references to the oxygen 
pressures (index 0) are returned as index 1, thus overwriting the data 
for cylinder 1. Therefore the end pressures are the same for both oxygen 
and diluent cylinders. The diluent series is slightly longer, therefore 
the start of the diluent series is not overwritten.

Unless you think that the problem should be solved elsewhere, I will 
invert the logic about cylinder numbers within gaspressures.c so that, 
when the oxygen pressures is addressed it will create a 'pseudo-cylinder 
0' and work with that.

Would this be a suitable solution or would you like to do something else?
Kind regards,
willem