trace Subroutine

public subroutine trace(x_init, y_init, phi_init, dphi, equi, x_end, y_end, phi_end, arclen, fluxexp, condition, stop_int, tracing_terminated, maxstep, istat)

Performs integration along field line. If condition is present, performs field line tracing while condition is true

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=FP),	intent(in)			::	x_init	Start point (x-coordinate)
real(kind=FP),	intent(in)			::	y_init	Start point (y-coordinate)
real(kind=FP),	intent(in)			::	phi_init	Start point (phi-coordinate)
real(kind=FP),	intent(in)			::	dphi	Toroidal distance to be traced
class(equilibrium_t),	intent(inout),		target	::	equi	Equilibrium defining the field line
real(kind=FP),	intent(out),	optional		::	x_end	End point (x-coordinate)
real(kind=FP),	intent(out),	optional		::	y_end	End point (y-coordinate)
real(kind=FP),	intent(out),	optional		::	phi_end	Actual phi-coordinate end point of integration (relevant if `condition` is present)
real(kind=FP),	intent(out),	optional		::	arclen	Length along field line
real(kind=FP),	intent(out),	optional		::	fluxexp	Flux expansion, i.e. 1 / Btor integrated along fieldline
procedure(condition_interface),		optional		::	condition	Trace is performed until condition is true
logical,	intent(in),	optional		::	stop_int	If = true, then the routine stops the integration once the condition is met. Otherwise, integration continues with integrand multiplied by zero. The default setting is false.
logical,	intent(out),	optional		::	tracing_terminated	True, if given as an input, and the tracing was terminated due the fulfillment of the given condition. False by default.
real(kind=FP),	intent(in),	optional		::	maxstep	Maximum stepsize for the integration
integer,	intent(out),	optional		::	istat	PARALLAX error status of trace routine. If present, the trace routine will trigger a warning in case of error, and return an error code. If not present, the trace routine will trigger an error.