NAME:
	MAP_CarrTime
 PURPOSE:
	Get start and end (in Julian days) of Carrington rotation IROT
 CALLING SEQUENCE:
	subroutine MAP_CarrTime(IROT,JDCar)
 INPUTS:
	IROT		integer			Carrington rotation number
 OUTPUTS:
	JDCar(2)	double precision	Start and end time (JD)
 CALLS: ***
	EARTH, Julian, MAP_TZERO
 INCLUDE:
	include		'sun.h'
 EXTERNAL:
	external	EARTH
 PROCEDURE:
	The approximate start time is estimated based on the starttime of
	Carrington rotation 1750 and the synodic rotation rate of Earth.
	MAP_TZERO is used to refine the estimate.
 MODIFICATION HISTORY:
	AUG-1993, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	MAP_DATA
 PURPOSE:
	Get modified Carrington variable for spacecraft location and observed
	locations
 CATEGORY:
	Celestial mechanics
 CALLING SEQUENCE:
	subroutine MAP_DATA(SC_NAME,iYr,N,NOBS,Doy,ZOBS,XSC,XOBS,nCar,JDCar)
 INPUTS:
	SC_NAME		real		external function; identifies spacecraft
	iYr		integer		year
	N		integer		# observation times
	NOBS		integer		# observations at each time
					(e.g. # sectors for Helios data)
	Doy(N)		real		day of year (fraction for time of day)
	ZOBS(N,NOBS)	real		heliographic longitudes of observed 
					locations (degrees, in [0,360))
 OUTPUTS:
	XSC(N)		real			modified Carrington variable for 
						spacecraft locations
	XOBS(N,NOBS)	real			modified Carrington variable for 
						observed locations
	nCar		integer			# start times of Carrington rotations
	JDCar(nCar)	double precision	Carrington start times in Julian days
						(JDCar is output from subroutine MAP_TZERO)
 CALLS: ***
	MAP_TZERO, XMAP_OBS_POS, XMAP_SC_POS
 EXTERNAL:
	external SC_NAME
 PROCEDURE:
 >	Loop over all observation time (N) and all simultaneous observations
	(NOBS) at each time.
 >	SC_NAME must also be declared EXTERNAL in the calling program
	SC_NAME is a user-written function which calculates the heliographic
		longitude XLNG of a spacecraft for a given time iYr,Doy
	The call to SC_NAME has the form:
		XLNG = SC_NAME(iYr,Doy)
	where iYr (integer*4) and Doy (real*4) are input and XLNG (real*4)
	is output.
 >	SC_NAME is available for Helios A (function HELIOS_1), Helios B
	(HELIOS_2) and Earth (EARTH); the function EARTH_ELIMB and EARTH_WLIMB
	can be used to handle earth-based limb observations.
 MODIFICATION HISTORY:
	JAN-1992, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	MAP_TZERO
 PURPOSE:
	Calculate list of start times for subsequent 'Carrington rotations'
 CATEGORY:
	Celestial mechanics
 CALLING SEQUENCE:
	subroutine MAP_TZERO(SC_NAME,iYr,Doy_IN,DELDOY,nCar,JDCar)
 INPUTS:
	SC_NAME		real			external function; identifies spacecraft
	iYr		integer			year
	Doy_IN		real			doy of year; including fraction for time of day
	DELDOY		real			required accuracy (in days) for the Carrington
						start times JDCar
	nCar		integer			# start times to be calculated
 OUTPUTS:
	JDCar(nCar)	double precision	Carrington start times in Julian days
 CALLS: ***
	Dbl2Str, Flt2Str, Int2Str, Julian, Say, Str2Str
 CALLED BY:
	MAP_CarrTime, MAP_DATA, N_CARRINGTON
 PROCEDURE:
 >	SC_NAME must be declared EXTERNAL in the calling program unit.
	SC_NAME is a user-written function which calculates the heliographic
		longitude XLNG of a spacecraft for a given time iYr,Doy
	The call to SC_NAME has the form:
		XLNG = SC_NAME(iYr,Doy)
	where iYr (integer*4) and Doy (real*4) are input and XLNG (real*4)
	is output.
 >	iYr,Doy_IN is the time where the search for start times begins.
	the first nCar Carrington start times after iYr,Doy_IN are calculated
 >	The spacecraft is supposed to move in the ecliptic, circling the Sun in
	the same direction as Earth (direct motion)
 >	The start time of a new Carrington rotation is defined as the time for
	which the heliographic longitude of the spacecraft is zero.
 MODIFICATION HISTORY:
	JAN-1992, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	MapWarp
 PURPOSE:
	Convert the vertical scale of a synoptic map from latitude to
	sin(latitude) or v.v.
 CALLING SEQUENCE:
	subroutine MapWarp(NX,NY,Z, YLB,YLE, ZMIN,ZMAX)
 INPUTS:
	NX,NY		integer	dimension of input grid
	Z(NX,NY,2)	real	grid fnc-values
	YLB,YLE		real	latitude (or sin(latitude))
				corresponding to bottom (i=1) and top (i=NY)
				row of input array Z.
 OUTPUTS:
	Z(NX,NY,2)	real	grid fnc-values in the new grid
	YLB,YLE		real	sin(latitude) (or latitude) of bottom
				and top row of output array Z
 CALLS: ***
	ArrR4GetMinMax, ArrR4Mask, BadR4, asind, nrInterpol, sind
 PROCEDURE:
 >	If the input values of YLB and YLE are both in the range [-1,1]
	the conversion is from sin(latitude) to latitude.
 >	Otherwise the conversion is from latitude to sin(latitude)
 >	For each longitude (column in array Z(I,J=1..NX,1) a cubic spline
	is calculated based on all unflagged grid points (Z(I,J,2) .eq. -1).
	The spline is used to calculate the fnc-values in the new grid.
	Grid points in the output grid are assigned the same flag status
	(value Z(.,.,2)) as the nearest grid point of the old grid in the 
	latitudinal direction of the old grid.
 MODIFICATION HISTORY:
	JUN-93, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	math
 PURPOSE:
	Define mathematical constants
 INCLUDED BY:
	BadI4, BadI8, BadR4, BadR8, CvR4, CvR8, EqKepler, EqKeplerd, GridSphere3D, IPSBase, IPSFuncQ
	KeplerOrbit, RebinSphere, SUNRA, SunRadius, ThomsonFarY, ThomsonLOS, ThomsonLOS3D
	ThomsonLOSFar, ThomsonLOSStep, ThomsonMid, ThomsonMidFar, ThomsonMidpoint
	ThomsonMidpointFar, ThomsonS10, Time2KeplerOrbit, Time2SunRA, Time2SunRadius
	TinyR4, asind, cosd, dasind, dcosd, pInfR4, smei_base, smei_cal, smei_eclipse
 PROCEDURE:

 NAME:
	MATRIX_INV_R4
 PURPOSE:
	Matrix inversion
 CATEGORY:
	Math: matrix algebra
 CALLING SEQUENCE:
	function MATRIX_INV_R4(N,A,IK,JK)
 INPUTS:
	N	integer			dimension of the NxN matrix A
	A	real*4			matrix
	IK,JK	integer			scratch arrays
 OUTPUTS:
	MATRIX_INV_R4  integer		0 if inversion not succesfull; 1 if succesfull
	A	real*4			inverse matrix
 PROCEDURE:
	Matrix inversion by Gauss-Jordan elimination with full pivoting
 MODIFICATION HISTORY:
	Joop Gronenschild (SRON)

 NAME:
	MATRIX_INV_R8
 PURPOSE:
	Matrix inversion
 CATEGORY:
	Math: matrix algebra
 CALLING SEQUENCE:
	function MATRIX_INV_R8(N,A,IK,JK)
 INPUTS:
	N	integer			dimension of the NxN matrix A
	A	double precision	matrix
	IK,JK	integer			scratch arrays
 OUTPUTS:
	MATRIX_INV_R8  integer		0 if inversion not succesfull; 1 if succesfull
	A	double precision	inverse matrix
 PROCEDURE:
	Matrix inversion by Gauss-Jordan elimination with full pivoting
 MODIFICATION HISTORY:
	Joop Gronenschild (SRON)

 NAME:
       MessengerOrbit	
 PURPOSE:
	Calculate Messenger orbit (position and velocity vectors)
 CATEGORY:
	/gen/for/lib/ephem
 CALLING SEQUENCE:
	subroutine MessengerOrbit(iYr,Doy,RR,VV)
 INPUTS:
	iYr		integer		year
	Doy		real		day of year
 OUTPUTS:
	RR(3)		real		position vector: ecliptic longitude and
					latitude (deg), radial distance (AU)
	VV(5)		real		velocity vector: ecliptic longitude and
					latitude (deg), magnitude, radial and
					tangential velocity (AU/day)
					(will be zero if the Messenger orbital
					data base is used; see PROCEDURE).
 CALLS: ***
	Julian, KeplerOrbit, Say
 PROCEDURE:
	Times have to be later than 2007/01/01 00 UT
 MODIFICATION HISTORY:
	JUL-1998, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
       JAN-2012, John Clover (UCSD/CASS)
                 Modified existing Stereo element program to use
                 Messenger elements

 NAME:
	MidExp
 PURPOSE:
 CATEGORY:
 CALLING SEQUENCE:
	subroutine MidExp( Funk, AA,BB,S,N )
 INPUTS:
 OUTPUTS:
 INCLUDE:
	include	'midpnt_inc.h'
 PROCEDURE:
	See Numerical Recipes
 MODIFICATION HISTORY:
	JUN-1993, Paul Hick (UCSD)

 NAME:
	MidInf
 PURPOSE:
 CATEGORY:
 CALLING SEQUENCE:
	subroutine MidInf( Funk, AA,BB,S,N )
 INPUTS:
 OUTPUTS:
 CALLED BY:
	ThomsonLOS, ThomsonLOS3D
 EXTERNAL BY:
	ThomsonLOS, ThomsonLOS3D
 INCLUDE:
	include	'midpnt_inc.h'
 PROCEDURE:
	See Numerical Recipes
 MODIFICATION HISTORY:
	JUN-1993, Paul Hick (UCSD)

 NAME:
	MidPnt
 PURPOSE:
 CATEGORY:
 CALLING SEQUENCE:
	subroutine MidPnt(Func, A,B,S,N)
 INPUTS:
 OUTPUTS:
 INCLUDE:
	include	'midpnt_inc.h'
 PROCEDURE:
	See Numerical Recipes
 MODIFICATION HISTORY:
	JUN-1993, Paul Hick (UCSD)

 NAME:
	midpnt_inc
 INCLUDED BY:
	MidExp, MidInf, MidPnt, MidSql, MidSqu
 PROCEDURE:
	Common part of the Mid* functions used in nrQRomo

 NAME:
	MidSql
 PURPOSE:
 CATEGORY:
 CALLING SEQUENCE:
	subroutine MidSql( Funk, AA,BB,S,N )
 INPUTS:
 OUTPUTS:
 INCLUDE:
	include	'midpnt_inc.h'
 PROCEDURE:
	See Numerical Recipes
 MODIFICATION HISTORY:
	JUN-1993, Paul Hick (UCSD)

 NAME:
	MidSqu
 PURPOSE:
 CATEGORY:
 CALLING SEQUENCE:
	subroutine MidSqu( Funk, AA,BB,S,N )
 INPUTS:
 OUTPUTS:
 INCLUDE:
	include	'midpnt_inc.h'
 PROCEDURE:
	See Numerical Recipes
 MODIFICATION HISTORY:
	JUN-1993, Paul Hick (UCSD)

 NAME:
	mkenv
 PURPOSE:
	Process logicals and symbols
 CATEGORY:
	Environment
 CALLING SEQUENCE:
	mkenv [-sym -log] [-set -get -del] [-value_only] [name=value]
 INPUTS:
	Command line switches and arguments
	-sym		process a logical
	-log		process a symbol
			If neither is set then -log is assumed

	-get		get value of symbol or logical
	-set		set a symbol or logical
	-delete		delete a symbol or logical
			If neither is set then
			-get is assumed if no name=value pair is specified
			-set is assumed if a name=value pair is specified

	-value_only	Only used if -get is set.
			By default -get will display a line of the form
				Logical: name = value
			if the logical or symbol is defined, or
				Logical: name is not defined
			if the logical or symbol doesn't exist.

			If -value_only is set then only the name of the logical
			or symbol is displayed if it exists; it it doesn't then
			nothing is displayed. This is useful for extracting the
			the value and storing it in a script variable:

				value=$($exe/mkenv -log -get temp)

			sets 'value' to the value of the logical temp, or to the
			null string (if temp doesn't exist).

	name=value	name: name of the logical or symbol
			value: value to be assigned to logical or symbol
 OUTPUTS:
	If -get is used a line is written to standard output giving the value
	of the specified logical or symbol.

	The exit status of the program is 0 on failure and 1 on success.
 CALLS: ***
	ForeignArg, LocFirst, Say, Str2Str, iCheckDirectory, iDeleteLogical [1]
	iDeleteLogical [2], iDeleteLogical [3], iDeleteSymbol [1], iDeleteSymbol [2]
	iDeleteSymbol [3], iGetFileSpec, iGetLogical [1], iGetLogical [2]
	iGetLogical [3], iGetSymbol [1], iGetSymbol [2], iGetSymbol [3], iSetLogical [1]
	iSetLogical [2], iSetLogical [3], iSetSymbol [1], iSetSymbol [2], iSetSymbol [3]
	icompress, itrim, lowercase
 INCLUDE:
	include 'dirspec [1].h'
	include 'dirspec [2].h'
	include 'dirspec [3].h'
	include 'dirspec [4].h'
 SIDE EFFECTS:
	-set and -delete update the ~/LOGFIL.TXT file
 PROCEDURE:
	This program is useful primarily on Linux and Unix for maintaining the
	file ~/LOGFIL.TXT containing 'logical' and 'symbol' definitions.
 MODIFICATION HISTORY:
	JUL-2000, Paul Hick (UCSD; pphick@ucsd.edu)

 NAME:
	MVBITS
 PURPOSE:
	Copy bits
 CATEGORY:
	Machine-dependent functions: Unix
 CALLING SEQUENCE:
	subroutine MVBITS(M,I,LL,N,J)
 INPUTS:
     M       integer         source
     I       integer         first bit in source M to be transferred
     LL      integer         number of bits in bit-field to be transferred
     J       integer         starting bit in destination N where bit-field 
                             is to be deposited
 OUTPUTS:
     N       integer         destination; only bits [J,J+LL-1] will be
                             modified.
 CALLS: ***
	BIC, BIS, BIT
 PROCEDURE:
     Works like the MVBITS subroutine on the VAX