It returns the partial derivative
,
given 2 input thermodynamic variables as defined by the InputSpec argument.
Default unit: 1/K
The general syntax for programs like Excel and programming languages like Fortran is:
= Fi( FluidObj,
InputSpec, Value1,
Value2, ErrorMsg)
The syntax for object oriented programming languages like VB, C++ and Matlab is:
= FluidObj.Fi(
InputSpec, Value1,
Value2, ErrorMsg)
Arguments:
FluidObj: |
In Excel it is the variable returned by SetFluid, in other programs or programming environments it is an object variable created at runtime. |
InputSpec: |
String |
Value1: |
Double |
Value2: |
Double |
ErrorMsg: |
String |
Excel Example:
= Fi( A1, "PT", 12.53, 253.42)
Notes: A1 is a cell containing the value returned by SetFluid.
The error message is not in the arguments list; in case an error occurs during the calculation, the value returned by the function is a string containing the error description.
The possible input specifications are listed in the table of available Thermodynamic State definitions.