Reminder: the g-function form is invoked by setting IQFUNC = 0
The choice of the function is made by setting the variables ( = 4 e. g.) and . When , the function is set through a call, where the analytic form is chosen by setting . When then the -function is interpolated from an array.
Here should be set equal to 1, to matches the requirements for
the PEST definition of the toroidal field.
and are input quantities. The variable is determined internally to fix the total current to a predefined quantity, determined from and the geometric parameters. The variable must be set to be the required in the input.
Note also that when the pressure is finite, use of the function to specify the current profile can cause problems near the axis. This can be avoided by choosing and , the exponents in the pressure profile. In this case is adjusted internally after each iteration so that . This option is invoked by setting . This option must be activated only when the pressure is finite.
We invoke the ORNL current profile with this choice of .
See the -profile specification for further details.
Here is set by interpolation from an array so that . Note that unlike the other functions and , here is a function of , not .
As before is adjusted internally to obtain a specified total current. When the current is set through as before, however when the current is specified explicitly in the input file along with the array , in the variable . The file is called GDISK(unit=10) and contains the following information.
The relevant segment of coding which reads the data is shown below:
call link('unit10=(gdisk,open)//) read(10,1000)igdata,curdsk 1000 format(1x,i3,e20.12) read(10,1100) . (psig(i),gdisk(i),gpdisk(i),pdisk(i),ppdisk(i),i=1,igdata) 1100 format(1x,5e20.12)