NAME:
	EarthSky3DLoc
 PURPOSE:
	A sky map is build up from a 2D grid of lines of sight. Returns the 3D
	positions (in heliographic coordinates) for all segments along each line
	of sight.
 CATEGORY:
	WWW: skymap
 CALLING SEQUENCE:
	FUNCTION EarthSky3DLoc, UT	, $
		longitudes	= longitudes, $
		nRA 		= nRA		, $
		nDE 		= nDE		, $
		nRR 		= nRR		, $
		dRR 		= dRR		, $
		equator 	= Equator	, $
		degrees 	= degrees	, $
		RA			= RA		, $
		DEC 		= DEC		, $
		zero_point	= zero_point, $
		zero_phase	= zero_phase, $
		zero_shift	= zero_shift, $
		rearth		= REarth	, $
		ut_earth	= TT		, $
		pa_earth 	= P 		, $
		elo_earth	= E 		, $
		elo_sun 	= S
 INPUTS:
	UT		scalar; type: standard time structure
				time when skymap is required
 OPTIONAL INPUT PARAMETERS:
	/degrees	if set then all in- and ouput angles are in degrees
				(default: radians)

	/equator	by default the sky map is in ecliptic coordinates (i.e. the
				horizontal plane is the ecliptic). If /equator is set the
				horizontal plane is Earth's equator
	/longitudes
				By default, the longitudinal (first) dimension in the output
				R and REarth is a Carrington variable within 0.5 of the
				Carrington variable corresponding to input time UT.
				If /longitudes is SET then heliographic longitudes are returned
				instead.
	zero_shift=zero_shift
			scalar; type: float; default: 0.0
				shifts the center of the sky grid. Instead of centering on the
				Sun the grid is shifted to increasing RA or ecliptic longitude
				by 'zero_shift'.
				The units must be consistent with the setting of /degrees.

	nRR		scalar; type: int; default: 20
				number of steps along lines of sight at each point in the sky
	dRR		scalar; type: float; default: 0.1
				step size along line of sight (AU)

	Lines of sight are specified as sidereal location in the sky (either
	RA/dec (/equator SET) or ecliptic longitude/latitude (/equator NOT set).

	If nRA and nDE are set to non-zero values then a grid of lines of sight
	covering the entire sky is created (see PROCEDURE): 	

	nRA		scalar; type: int; default: 72
				nr of points in skymap in longitudinal direction (either right
				ascensions of ecliptic longitude)
				If nRA or nDE is set to zero then RA and DEC are used as input.
	nDE		scalar; type: int; default: 36
				nr of points in skymap in latitudinal direction (either declination
				or ecliptic latitude)

	Alternatively, set the product nRA*nDE=0 and specify lines of sight explicitly
	through keywords RA,DEC:

	RA[nLOS]
			scalar or array; right ascensions (/equator SET) or
				ecliptic longitudes (/equator NOT set)
	DEC[nLOS]
			scalar or array; declinations (/equator SET) or
				ecliptic latitudes (/equator NOT set).

 OUTPUTS:
	Result	array[3,nRA,nDE,nRR]; type: float
			array[3,nLOS,nRR]; type: float (if nRA or nDE is zero)
				3D locations (in heliographic coordinates) where values need
				to obtained by interpolation on the 3D arrays.
				R[0,*,*,*]: Carrington variables within 0.5 of CarringtonVar(UT)
							(/longitudes NOT set) or heliographic longitudes
							(if /longitudes SET)
				R[1,*,*,*]; heliographic latitudes
				R[2,*,*,*]: heliocentric distances (AU)
 OPTIONAL OUTPUT PARAMETERS:
	Only if nRA*nDE = 0 on input:

	RA		array[nRA]; type: float
				right ascensions or ecliptic longitudes across sky
				(with RA/longitude of Sun in center of array)
				i.e. RA = (RA Sun at time UT) -pi+2*pi/nRA*[0.5,1.5,...,nRA-0.5]
	DEC		array[nDE]; type: float
				declination or ecliptic latitude across sky
				(with decl/lat zero in center of array)
				DE = -pi/2+pi/nDE*[0.5,1.5,...,nDE-0.5]

	Depending on setting of /equator, RA and DEC define a regular grid in
	equatorial or ecliptic sky coordinates for the centers of the boxes for the
	lines of sight used to build the skymap with the position of the Sun
	centered in the RA/longitudinal direction.

	zero_phase=zero_phase
			scalar; type: float
				right ascension or ecliptic longitude of Sun (plus zero_shift)
				if specified) at time UT, i.e. this is the value on which RA is centered
	zero_point=zero_point
			scalar; type: float
				right ascension or ecliptic longitude of Sun (plus zero_shift)
				at time UT (i.e. same as 'zero_phase'; should stay to ensure
				that the values are consistent when fed e.g. to PlotEarthSkymap)
	REarth	array[3]; type: float
				heliocentric location Earth in heliographic coordinates
				REarth[0]: Carrington variable within 0.5 of CarringtonVar(UT)
							(/longitudes NOT set) or heliographic longitudes
							(if /longitudes SET)
				REarth[1]; heliographic latitude
				REarth[2]: heliocentric distance (AU)
	pa_earth=pa_earth
			array[nRA,nDE,nRR]; type: float
				line of sight position angle measured counterclockwise
				from ecliptic north
	elo_earth=elo_earth
			array[nRA,nDE,nRR]; type: float
				line of sight elongations: angle (Sun-Earth-los segment)
	elo_sun=elo_sun
			array[nRA,nDE,nRR]; type: float
				angle Earth-Sun-los segment
 INCLUDE:
	@compile_opt.pro							; On error, return to caller
 CALLED BY:
	vu_earthskymap
 SEE ALSO:
	EarthTransit3DLoc, PlotEarthSkymap
 CALLS: ***
	AngleRange, CarringtonNear, CarringtonVar, CvPointOnLos, CvSky, InitVar, SuperArray
	SyncArgs, ToRadians, big_eph, gridgen, jpl_body
 PROCEDURE:
 >	The sky map is build from nRA*nDE line of sight integrations through the
	F3D array. The locations in the sky of the lines of sight are
		RA/Lng    = (RA/Lng Sun) -180 + (360./nRA)*[0.5, 1.5, .. , nRA-0.5 ]
		Decl./Lat = - 90 + (180./nDE)*[0.5, 1.5, .. , nDE-0.5 ]
		Dist along los = dRR*[0.5,1.5,...,nRR-1]
	Note that each line of sight is centered on a 'box' of 360/nRA by 180/nDE
	degrees, and that all lines of sight together cover the entire sky.
 MODIFICATION HISTORY:
	AUG-1999, Paul Hick (UCSD/CASS)
	OCT-2004, Paul Hick (UCSD/CASS)
		Added zero_shift keyword.
	APR-2006, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
		Added keyword /longitudes (the previous version always returned
		heliographic longitudes). Add option to explictly specify lines of sight
		in RA,DEC after setting nRA*nDE=0.

 NAME:
	EarthTransit3DLoc
 PURPOSE:
	Provides 3D heliographic coordinates for all lines of sight used for a 'transit sweep' across the sky
 CATEGORY:
	WWW: skymap
 CALLING SEQUENCE:
	FUNCTION EarthTransit3DLoc, UT, $
		longitudes	= longitudes, $
		nRA 		= nRA		, $
		nDE 		= nDE		, $
		nRR 		= nRR		, $
		dRR 		= dRR		, $
		equator 	= equator	, $
		degrees 	= degrees	, $
		band		= band		, $
		solar		= solar 	, $
		geolng		= geolng	, $
		RA			= RA		, $
		DEC 		= DEC		, $
		zero_phase	= zero_phase, $
		zero_point	= zero_point, $
		rearth		= REarth	, $
		ut_earth	= TT		, $
		pa_earth 	= P 		, $
		elo_earth	= E 		, $
		elo_sun 	= S
 INPUTS:
	UT		scalar; type: time structure
				universal time, UT
				(usually UT corresponding to local noon at geographic longitude 'geolng')
 OPTIONAL INPUT PARAMETERS:
	/degrees	if set then all in- and ouput angles are in degrees (default: radians)

	Four parameters define the grid used to calculate the sky map (see PROCEDURE)

	nRA		scalar; type: int; default: 36
				# points in skymap in longitudinal direction (either right ascensions
				of ecliptic longitude). Note that nRA may be modified if keyword
				band is used.
	nDE		scalar; type: int; default: 18
				# points in skymap in latitudinal direction(either declination or
				ecliptic latitude)
	nRR		scalar; type: int; default: 20
				# steps along lines of sight at each point in the sky
	dRR		scalar; type: float; default: 0.1
				step size along line of sight (AU)

	geolng=geolng
			scalar; type: any; default: 0
				geographic longitude of observing location
	/equator
			by default the local meridian is set up as a strip of sky centered on the
				intersection with the ecliptic. This results in a sweep with the Sun
				centered, and the ecliptic along the horizontal axis (but see RESTRICTIONS).
				If /equator is set then the strip of sky is centered on the equator, i.e.
				the strip covers the local meridian from equatorial north to equatorial south.\
				This is a more strict interpretation of the concept of a 'transit sweep', but
				has the disadvantage that the Sun is not at the center of the sky map.
	band	scalar; type: float
				Width of strip to be processed (in hours)
				If band is not set then meridian strips covering 24 hours centered
				around UT are selected. Use this keyword to extract only a partial strip
				of sky covering less than 24 hour.
	/solar	by default the meridian strips are centered around the meridian strip at time UT.
				Setting /solar rearranges the strips, putting the meridian strip at noon in
				the center (see PROCEDURE)
	/longitudes
 OUTPUTS:
	R		array[3,nRA,nDE,nRR]; type: float
				3D locations (in heliographic coordinates) where values need to obtained
				by interpolation on the 3D arrays.
	nRA		scalar; type: integer
				if keyword band is set then nRA is set to the number of meridians
				inside the RA range of width 'band'.
 OPTIONAL OUTPUT PARAMETERS:
	RA		array[nRA]; type: float
				Right ascension for nRA UT times covering 24 hours centered on UT
	DEC		array[nDE]; type: float
				DEC = -pi/2+pi/nDE*[0.5,1.5,...,nDE-0.5]
				RA and DEC define a regular grid in sky coordinates for the centers of
				the boxes for the lines of sight used to sweep of the sky
	zero_point=zero_point
			scalar; type: float
				/solar NOT set: RA angle for local meridian at 'geoloc' on time UT
				/solar set    : RA angle of Sun at time UT
	zero_phase=zero_phase
			/solar NOT set:
				scalar, type: float
					RA angle for local meridian at 'geoloc' on time UT
					(i.e. same as zero_point)
			/solar set    :
				array[nRA]; type: float
					RA angles of Sun for nRA UT times covering 24 hours centered
					on UT (same times as used for output array RA).
					(i.e. 'zero_point' is approximately centered in 'zero_phase')
	pa_earth=pa_earth
			array[nRA,nDE,nRR]; type: float
				line of sight position angle measured counterclockwise
				from ecliptic north 
	elo_earth=elo_earth
			array[nRA,nDE,nRR]; type: float
				line of sight elongations: angle (Sun-Earth-los segment)
	elo_sun=elo_sun	array[nRA,nDE,nRR]; type: float
				angle (Earth-Sun-los segment)
	rearth=REarth	array[3,nRA]; type: float
				heliocentric locations Earth in heliographic coordinates
 INCLUDE:
	@compile_opt.pro				; On error, return to caller
 CALLS: ***
	CarringtonNear, CarringtonVar, CvPointOnLos, CvSky, InitVar, IsType, SuperArray
	TimeGST, TimeOp, TimeSet, TimeUnit, ToRadians, big_eph, gridgen, jpl_body
 CALLED BY:
	vu_earthskymap
 RESTRICTIONS:
	If /equator is NOT set then the ecliptic is put on the horizontal axis. This is
	done using a kludge. Each meridian strip (-90 to +90 degrees in declination with
	the equator in the center, is shifted vertically to put the ecliptic in the center.

	The sweep across the sky covers 24 hours in UT. Since UT is a solar time, the sweep covers
	a little more than 360 degree of sky. However, the RA array still covers exactly 360
	degrees (RA is passed to PlotEarthSkyMap to make a Hammer-Aitoff or fish-eye map).
 PROCEDURE:
 >	UT is used to set up an array of nRA equally spaced times covering UT-12h to UT+12h
		TT = UT+((.5+findgen(nRA))/nRA-.5)*(24)
	(if 'band' is specified then only UT +/- band/2 is used).
 >	The geographic longitude, together with GST, is used to calculate the RA
	of the local meridian (hour angle zero) at times TT
 >	At each RA(TT) value nDE equally spaced declination are taken
		DEC = ((.5+findgen(nDE))/nDE-.5)*90
 >	The resulting strips along the local meridian patched together give
	a (partial) sweep of the sky. The return array RA is a monotonic increasing
	array inside [-180,+180].
 >	If /solar is NOT set then the return array zero_phase contains the right ascension
	of the local meridian at time UT.
	If /solar is set then the return array zero_phase contains the right ascension of
	the sun at the times centered on UT used also to calculate RA.
	The scalar 'zero_point'  and array 'zero_phase' are used to center the proper
	RA in a skymap by subtracting it from RA.
 >	The output array REarth gives the location of Earth at times TT
 MODIFICATION HISTORY:
	SEP-1999, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	eclipsed_area
 PURPOSE:
	Calculates fraction of solar disk eclipsed by Moon or Earth
 CATEGORY:
	gen/idl/toolbox
 CALLING SEQUENCE:
	area = eclipsed_area(loc_sun, loc_em, [/degrees, ut=ut])
 INPUTS:
	loc_sun 		array[3,n] or array[3,2,n]; type: float
						if array[3,n]; location of Sun in spherical coordinates
							(RA,dec,distance, or long, lat, distance)
						if array[3,2,n] then array[3,0,*] specifies the location
							of the Sun and array[3,1,*] specifies the location
							of the Moon or Earth. In this case loc_em is ignored.
	loc_em			array[3,n]; type: float
						location of Earth or Moon in same coordinates as for the Sun.
 OPTIONAL INPUT PARAMETERS:
	/degrees		if set, all angles are in degrees (default: radians)
	/plotc			if set, then results are plotted
						(angular separation of Sun and Moon or Earth, and fraction of
						disk eclipsed).
	ut=ut			array[*]; type: structure
						time structure used to plot a time axis (only used
						if /plotc is set).
 OUTPUTS:
	area			array[n]; type: float
						fraction of solar disk eclipsed by Moon or Earth.
 OPTIONAL OUTPUT PARAMETERS:
	elo 			array[*]; type: float
						angular distance between Sun and Moon or Earth
 INCLUDE:
	@compile_opt.pro
 CALLS: ***
	BadValue, Elongation, InitVar, IsTime, IsType, PlotCurve, SyncArgs, ToDegrees, ToRadians
 CALLED BY:
	smei_frm_cvhdr, smei_frm_eclipse
 PROCEDURE:
 MODIFICATION HISTORY:
	OCT-2004, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	Elongation
 PURPOSE:
	Get angle between two vectors
 CATEGORY:
	Tricks
 CALLING SEQUENCE:
	FUNCTION Elongation, Los1, Los2, Los3, Los4, Los5, Los6, degrees=degrees, rectangular=rectangular
 INPUTS:
	Los1, Los2		any arrays with 1st dimension of 2 or 3 elements
					containing vector coordinates in spherical
					(longitude, latitude, distance) or rectangular (x,y,z)
					coordinates.
 OPTIONAL INPUT PARAMETERS:
	/degrees		if set, all angles are in degrees (default: radians)
	/rectangular	if set, Los1 and Los2 are in rectangular (x,y,z) coordinates
 OUTPUTS:
	E				elongations in range [0,180] degrees.
					The array size is the same as for the input array with
					the 1st dimension removed.
 INCLUDE:
	@compile_opt.pro			; On error, return to caller
 CALLS: ***
	SubArray, SuperArray, SyncArgs, SyncDims, ToRadians
 CALLED BY:
	PlotEarthSkymap, RemoteView_FOV_Cube, RemoteView_Init_FOV, ThomsonLOSRomb
	ThomsonLOSStep, eclipsed_area, smei_frm_summary, smei_hdr_plot, smei_star_fit
	vu_point_source
 EXAMPLE:
	Specify vectors in spherical coordinates (all in the equatorial plane).
	Every vector in los2 is combined with the vector in los1. All angles are in degrees.

	los1 = [0,0,1]
	los2 = [[0,0,1], [45,0,1], [90,0,1], [135,0,1], [180,0,1]]
	e = elongations(los1, los2, /degrees)
	print, e
		0.000000      45.0000      90.0000      135.000      180.000
	help, los1, los2, e
		LOS1            INT       = Array[3]
		LOS2            INT       = Array[3, 5]
		E               FLOAT     = Array[5]
 PROCEDURE:
	Apply the following to the longitude and latitude angles:
	L = acos( sin(lat1)*sin(lat2)+cos(lat1)*cos(lat2)*cos(lng1-lng2) )
 MODIFICATION HISTORY:
	AUG-2000, Paul Hick (UCSD/CASS)
	DEC-2000, Paul Hick (UCSD/CASS)
		Modified to accept vector arrays of any number of dimensions
	JUL-2006, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
		Added option to provide components of vectors sepately
		(using 4 or 6 arguments).

 NAME:
	env_slashes
 PURPOSE:
	Fixes environment variables on Windows
 CATEGORY:
	gen/idl/environment
 CALLING SEQUENCE:
	env_slashes
 INPUTS:
	(from Windows by retrieving results of spawning
	the DOS 'set' command).
 OUTPUTS:
	(modified env variables)
 CALLS: ***
	FILEPATH, txt_read
 PROCEDURE:
	On Windows SSW sets up environment variables with a mix
	of back- and forward slashes. This causes problems for e.g.
	the IDL dialog_pickfile procedure.
	This procedure runs through all env variables and changes
	forward slashes to backward slashes. Only env variables of
	the form SSW_*_INSTR are not modified. 
 MODIFICATION HISTORY:
	FEB-2002, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	EPOCH2JD


 PURPOSE:
	Convert SMEI epoch to Julian Day.


 CATEGORY:
	Utils


 CALLING SEQUENCE:
	jd = epoch2jd(epoch)


 INPUTS:
	epoch	numeric	The SMEI epoch(s) to convert.


 OUTPUTS:
	jd	double	The julian day number(s) of the epoch(s)


 CALLS: ***
	doy2jd
 CALLED BY:
	FF_SUMMARY
 MODIFICATION HISTORY:
	Original: 25/3/03; SJT

 NAME:
	EqKepler
 PURPOSE:
	Kepler's equation is used in the determination of orbital positions.
	It gives the relation between mean and eccentric anomaly (for given
	orbit eccentricity).
 CATEGORY:
	smei/gen/idl/ephem
 CALLING SEQUENCE:
	F = EqKepler(E,arg)
 INPUTS:
	E		scalar; type: float
				eccentric anomaly (radians)
	arg		array[2], type: float
				arg[0]	mean anomaly 	  (radians)
				arg[1]	orbit ellipticity (eccentricity)
 OUTPUTS:
	EqKepler	fnc value
 EXTERNAL BY:
	KeplerOrbit
 PROCEDURE:
	The eccentric anomaly is the root of Kepler's equation:
	EqKepler = X-arg[1]*sin(X)-arg[0] = 0
	See O. Montenbruck, "Practical Ephemeris Calculations", Springer
	(1989), par. 3.1.1.4, p. 44
 MODIFICATION HISTORY:
	1990, Paul Hick (UCSD)

 NAME:
	EulerRotate
 PURPOSE:
	Calculate spherical angles in rotated coordinate system
 CATEGORY:
	gen/idl/toolbox/math	
 CALLING SEQUENCE:
	Result = EulerRotate(ABG,In,degrees=Degrees)
 INPUTS:
	ABG			array[3] or multi-dimensional array[3,..] with first dimension of 3
					elements. If multi-dimensional, then:
					1. either the array structure, except for the 1st dimension, is the same
					   as for In. Each position in In is rotated using the matching ABG set.
					2. or In is only 1-dimensional i.e. contains only one position. Then
					   each ABG combination is applied to this one position.
					Euler angles [A, B, G]
					A		phase angle of the pole Z(new) in old coordinate system
					B		polar angle of the pole Z(new) in old coordinate system
					G		phase angle of X(new) in coordinate system (2)

	/rectangular NOT SET:
		In			any multi-dimensional array with first dimension of 2 or 3 elements.
					array[0,..] is the longitude and array[1,..] the latitude;
					array[3,..] (usually the radial distance) is not modified.
	/rectangular SET:
		In			array[3,..], any multi-dimensional array with array[i,..] (i=0,2)
					the x,y and z-components
 OPTIONAL INPUTS:
	/rectangular	if set, the input array In is interpreted as vectors in rectangular
					coordinates.
					if not set, the input array In is assumed to be in spherical coordinates
					(longitude, latitude, radial distance).
	/degrees		if set, input and output is in degrees
 OUTPUTS:
	/rectangular NOT SET:
					double array with same structure as input array In
					array[0:1,..] are longitude and latitude in new coordinate system
					(0<=Lng<360, -90<=Lat<=90)
	/rectangular SET:
					array[3,..] with same structure as input array In
					x,y,z coordinates in new coordinate system
 INCLUDE:
	@compile_opt.pro						; On error, return to caller
 CALLS: ***
	CvT3d, SubArray, SuperArray, SyncDims, ToRadians
 CALLED BY:
	CvMag, CvPrecess, CvSky, FishEye, HammerAitoff, KeplerOrbit, MercatorProj
	PlotEarthSkymap, PlotPlanarCut, RemoteView_CMEDensity, RemoteView_Init_FOV
	RemoteView_StereoStates, RotationMeasure, qvu_draw, smei_star_stdmaps
	vu_planarcut
 PROCEDURE:
 >	/rectangular NOT SET:
	Given longitude (phase angle) and latitude (90-polar angle) of a point
	in some coordinate system [axes: X(old),Y(old),Z(old)], angles are
	calculated in the new coordinate system [axes: X(new),Y(new),Z(new)]
	rotated with respect to the original one over the Euler angles Alfa,
	Beta, Gamma.
	The rotation from old to new system is realized by
	(1) rotation around Z(old) over Alfa  ---> X(1),Y(1),Z(1)=Z(old)
	(2) rotation around Y(1)   over Beta  ---> X(2),Y(2)=Y(1),Z(2)=Z(new)
	(3) rotation around Z(new) over Gamma ---> X(new),Y(new),Z(new).
 >	/rectangular SET:
	The 3D rotation !p.t is used do do the transformation.
 MODIFICATION HISTORY:
	1989, Paul Hick (MPAE,UCSD)
	FEB-1998, Paul Hick (UCSD/CASS), added call to cvt3d to handle conversion
		of rectangular coordinates
	JUN-2000, Paul Hick (UCSD/CASS), added option to rotate
		single position using multiple Euler angle combinations.
	SEP-2001, Paul Hick (UCSD/CASS),
		removed a restriction on ABG for a transformation of rectangular
		coordinates. Only one set of Euler angles was allowed. Now separate
		Euler angles can be specified for each vector in 'In'; these are
		processed using an explicit do-loop).
	AUG-2004, Paul Hick (UCSD/CASS)
		For rotations of spherical coordinates (/Rectangular NOT set) a safety
		check cos(angle) > (-1) made bad coordinate values disappear
		(!values.f_nan > 1 returns 1, while !values.f_nan < 1 returns !values.f_nan).
		The safety check now explicitly checks for bad values, so they don't
		get lost.
	DEC-2005, Paul Hick (UCSD/CASS, pphick@ucsd.edu)
		Bug fix. When 1-element arrays are input at In and In1, the output would
		be a scalar. The output should always have the same structure as the input.

 NAME:
	even_light
 PURPOSE:
	Program used for the certification of the SMEI cameras using
	the light box data take in the 3th floor clean room.
 CATEGORY:
	stuff
 CALLING SEQUENCE:
 INPUTS:
 OPTIONAL INPUT PARAMETERS:
 OUTPUTS:
 OPTIONAL OUTPUT PARAMETERS:
 CALLS: ***
	ArrayLocation, BadValue, CV_COORD, CenterOfMass, EVEN_LIGHT_BIN_PHI
	EVEN_LIGHT_BIN_RAD, EVEN_LIGHT_CENTROID, EVEN_LIGHT_FIRSTGUESS
	EVEN_LIGHT_GEOMETRIC_FIX, EVEN_LIGHT_PRORATE, EVEN_LIGHT_SHIFT
	EVEN_LIGHT_VIEW, FILEPATH, InitVar, Inside_Wedge, LSQQUADRATICFIT, MEAN, REVERSE
	SuperArray, TimeOp, TimeSystem, TimeUnit, View, WhatIs, bin_read, bin_write, destroyvar
	even_light_background, even_light_corrections, even_light_pedestal
	even_light_photometry, even_light_registration, flat_centerofmass, gridgen
	img_read, lsqCircleFit, twin, wedge_bounding_box
 PROCEDURE:
 MODIFICATION HISTORY:
	???-200?, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	even_light_background
 PURPOSE:
 INPUTS:
	adus
	gain
	P1
	P2
 OUTPUTS:
	Background corrected adus
 INCLUDE:
	@compile_opt.pro		; On error, return to caller
 CALLED BY:
	even_light, even_light_info
 PROCEDURE:
	Calculate (adus-P1)/gain-P2
 MODIFICATION HISTORY:
	???-????, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	even_light_corrections
 PURPOSE:
 CATEGORY:
 INPUTS:
	hhvv				identifies frame sequence
	spot_centroid		x-y coordinates of spot centroids (relative to center0)
	good_spot			list of spot indices to be used for obtaining corrections
	bins_axis
	bins_step
	img_nr
	center0				center of fov arc (pix)
 OUTPUTS:
	center0
	dcenter
	optaxis0
	doptaxis
	binwidth
	dbinwidth
	y_run
 INCLUDE:
	@compile_opt.pro		; On error, return to caller
 CALLS: ***
	CV_COORD, FILEPATH, Get_Page, InitVar, IsDisplay, LSQQUADRATICFIT, MEAN, Set_Page
	SuperArray, lsqCircleFit, qSet_Page, twin
 CALLED BY:
	even_light, even_light_info
 MODIFICATION HISTORY:
	???-????, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	even_light_figures
 PURPOSE:
	Draw stuff
 INCLUDE:
	@compile_opt.pro		; On error, return to caller
CALLS
InitVar
 CALLS: ***
	InitVar, MEAN, QBARGRAPH, STDDEV, flt_read, gridgen, plot3darc, plot3dline, plot3dtext
	setup3d, twin
 MODIFICATION HISTORY:
	???-????, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	even_light_info
 PURPOSE:
 CATEGORY:
 INCLUDE:
	@compile_opt.pro		; On error, return to caller
 CALLS: ***
	BadValue, CORRELATE, FILEPATH, InitVar, IsType, MEAN, STDDEV, SuperArray, bargraph
	bin_read, destroyvar, even_light_background, even_light_corrections
	even_light_pedestal, even_light_photometry, even_light_plot
	even_light_registration, lsqNormalFit, qplot, twin
 PROCEDURE:
  0: prints table of geometric constants to screen
		/widget		calls qplot widget
  1: scatter plot: X0 vs. Y0
  2: scatter plot: phi0 vs. R0
  3: scatter plot: dX0 vs. dY0
  4: scatter plot: VP vs. VR
  5: scatter plot: bin widths vs. change in binwidth

  6: scatter plot: P1+P2 vs. P2
  7: widget with P1+P2, P1, P2 (including errors)
  8: prints table of pedestal determination
		/redo: uses adu_per_bin to recalculate pedestals before printing

		if run_id is specified (single run) then a scatter plot of gain
		vs. residual background for all images in the run is displayed.
		if keyword /raw is set then gain vs. raw background is displayed

		/excl_img: list of images to be excluded from recalculation of
		pedestals and scatter plots.

  9: photometric certification summary
		displays summary plot of photometry: histgram of relative
		photometric errors for all spots; gain, blank readout, dark reference
		readout, raw background and residual background as a function of image
		number.

		if keyword /spots is set, all residual time series are plotted before
		displaying the summary plot

		if run_id is not specified (all_runs) then the qplot widget is shown
		with the median photometic error for all runs.

		if keyword /redo is set than the gains are recalculated using
		the adu_per_bin array. Keyword excl_img can be used to exclude images
		from the recalculation.
 MODIFICATION HISTORY:
	???-????, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	even_light_pedestal
 PURPOSE:
	
 CATEGORY:
	camera/idl/cert
 CALLING SEQUENCE:
 INPUTS:
 OPTIONAL INPUT PARAMETERS:
 OUTPUTS:
 OPTIONAL OUTPUT PARAMETERS:
 INCLUDE:
	@compile_opt.pro		; On error, return to caller
 CALLS: ***
	InitVar, LINFIT, LocalExtrema, MEAN, gridgen
 CALLED BY:
	even_light, even_light_info
 PROCEDURE:
 MODIFICATION HISTORY:
	???-200?, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	even_light_photometry
 PURPOSE:
 CATEGORY:
 INCLUDE:
	@compile_opt.pro		; On error, return to caller
 CALLS: ***
	BadValue, FILEPATH, Get_Page, InitVar, IsDisplay, IsType, MEAN, STDDEV, Set_Page, bargraph
	destroyvar, qSet_Page, twin
 CALLED BY:
	even_light, even_light_info
 PROCEDURE:
 MODIFICATION HISTORY:
	???-????, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	even_light_platescale
 PURPOSE:
 INCLUDE:
	@compile_opt.pro		; Return to caller
 CALLS: ***
	MEAN, STDDEV, gridgen
 MODIFICATION HISTORY:
	???-????, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	even_light_plot
 PURPOSE:
 CATEGORY:
 INCLUDE:
	@compile_opt.pro		; On error, return to caller
 CALLS: ***
	InitVar, MEAN, STDDEV, twin
 CALLED BY:
	even_light_info
 PROCEDURE:
 MODIFICATION HISTORY:
	???-????, Paul Hick (UCSD/CASS; pphick@ucsd.edu)

 NAME:
	even_light_registration
 PURPOSE:
 CATEGORY:
 CALLING SEQUENCE:
 INPUTS:
 OPTIONAL INPUT PARAMETERS:
 OUTPUTS:
 OPTIONAL OUTPUT PARAMETERS:
 INCLUDE:
	@compile_opt.pro		; On error, return to caller
 CALLS: ***
	BadValue, CV_COORD, FILEPATH, Get_Page, InitVar, IsDisplay, LINFIT, PlotCurve, STDDEV
	Set_Page, bargraph, qSet_Page, twin
 CALLED BY:
	even_light, even_light_info
 PROCEDURE:
 MODIFICATION HISTORY:
	???-200?, Paul Hick (UCSD/CASS; pphick@ucsd.edu)