//*******************************************************************************************
// The ORCHESTRA node type file, contains the definition of the cell variables.
// Cell variables store the system composition at the cell location and can be used for input and output.
// Users can define their own cell variables. 
// All ORCHESTRA cells have the same set of cell variables.
//  
// There are two types of cell variables, 
//   1) static variables, with a single instance shared by all cells (e.g. time, dt)
//   2) normal variables, with an individual instance for each cell (e.g. depth, pH, )
//
// Typical examples of static variables are e.g. time and delta time.
// Definition as static variable assures that all system cells share the same value for time   
// Definition  is as follows:

@static: dt		0
@static: time	0

// Normal cell variables have an individual instance and value for each cell.
// These variables  can be defined in two ways, either vertically:
@Var: H+.tot	  0.00278273 
@Var: H+.diss	2.35679e-005
@Var: H+.ads 	0
@Var: H+.logact   -6
@Var: H+.d		0


// or horizontally, which is the same syntax as input/output files, which can be useful
Var: 		pH 	H+.tot	H+.diss		........		H+.d     
Default:	7	0.00278273  2.35679e-005	........		0



Automatic definition of node variables from ORCHESTRA version 1/11/2007

Up till now in ORCHESTRA all cell/node variables had to be defined specifically in the node type
definition file (usually column.dat). 
This was very flexible, as it allowed users to determine exactly which variables were stored between
chemical equilibrium calculations, and which ones were kept local to the chemistry. 
However at the same time it was also quite tedious to define each variable that was used in output or 
input files first as cell variable in the node type definition. 

Therefore, from version 1/11/2007 ORCHESTRA automatically defines node/ cell variables + default values based on the 
input and output files and also on the calculators (chemistry and transport) in the system.

So, if for example, the variable pH is used in input, or output file, this variable is automatically defined
as cell variable, and can be used for output. (no definition in column.dat necessary)

In the calculators relevant variables can now be defined as "global" which makes that these variables will also be 
used as cell variables. 

The standard chemical and transport objects are adapted so that the relevant variables are automatically defined globally,
together with proper defaults values. 

So, apart from static variables, no variable definitions are required in column.dat


Other kewwords:

@echo: shows the defined node variables together with their default value and definition file