/*TotalPressure determine the gas and line radiation pressures for current conditions */
double TotalPressure(void);

/*RamPressure determine the ram pressures for current conditions, 
 * in TotalPressure */
double RamPressure(void);

/* variables dealing with pressure across model */
EXTERN struct t_pressure {

	/* lowest and highest total current pressure to desired
	 * pressures in model, a measure of how well converged it is.  This
	 * includes total pressure, so in a constant gas pressure model will
	 * show a large excursion */
	float PresLow, 
	  PresHigh;

	/* PressureInit - total pressure at the illuminated face */
	float PressureInit,
		PresPowerlaw;

	/* the initial and current ram pressure */
	float RamPresInit , RamPres ;

	/* the current pressure, and the correct pressure, the ratio
	 * of the two is the error */
	float pnow, 
	  pcorec;

	/* flag saying whether or not incident continuum should be included
	 * in total pressure, turned off with constant gas pressure */
	int lgConPres;

	/* total pressure related variables
	 * PresInteg is integral */
	float pinit, 
	  PresInteg, 
	  pinzon;

	/* lgRadPresON says whether radiation pressure enabled, turned ooff with
	 * constant density, constant gas pressure commands, on with constant pressure
	 * RadPres is trapped line radiation pressure for current zone
	 * RadBetaMax is largest ratio of radiation to gas pressure
	 * GasPres is gas pressure, nkT, set in ptot
	 * PresMas is largest pressure that occurred in the calculation */
	int lgRadPresON;
	float RadPres, 
	  plines[20], 
	  RadBetaMax, 
	  pbeta, 
	  GasPres, 
	  PresMax;

	/* pointer to line with greatest radiation pressure */
	long int ipPradMax;

	/* string with label for line with greatest contributrion to pressure*/
	char chLineRadPres[11];

	/* lgPradCap true if radiation pressure capped on first iteration
	 * lgPradDen capped by thermalization length */
	int lgPradCap, 
	  lgPradDen;

	/*
	 *flag true if radiation pressure is turned on, part of total pressure
	 */
	int lgRadPrsON;

	/* option to not abort on high radiation pressure - set TRUE in initialization,
	 * set false with NO ABORT on constant radiation pressure command */
	int lgRadPresAbortOK;

	/* label describing the pressure law for current calculation
	 * 'DLW2' is tabden interpolated table */
	char chCPres[5];

	}	pressure;