CACK_OOPS_!@#$%^&*()*&^%$#@!_SPOO_KCAC T3D_READBt.FOR
C+
C NAME:
C 	T3D_ReadBt
C PURPOSE:
C	Get radial and tangential magnetic field data at source surface
C CATEGORY:
C	I/O
C CALLING SEQUENCE:
	logical function T3D_ReadBt(t3d,XCbegMAT,XCendMAT,XCbegROI,XCendROI,BR3D,BT3D,Btmp)
C INPUTS:
C	t3d(*)			real	contains information about reconstruction
C					(the array is filled by href=T3D_fill_global=
C					and href=T3D_fill_time=).
C
C	XCbegMAT(nTim)	real		start Carrington variable of matrix (- NCoff)
C	XCendMAT(nTim)	real		end Carrington variable of matrix (- NCoff)
C					(range of matrix typically is three Carrington rotations)
C	XCbegROI(nTim)	real		start Carrington variable of region of interest
C	XCendROI(nTim)	real		end Carrington variable of region of interest
C					(the region of interest typically covers one whole
C					Carrington rotation
C
C	Btmp(nLng,nLat,2)	real	scratch array
C OUTPUTS:
C	BR3D(nLng,nLat,nRad,nTim)
C				real	radial magnetic field
C	BT3D(nLng,nLat,nRad,nTim)
C				real	tangential magnetic field
C CALLS:
C	MapReadt, MapReadSRF, ArrR4Copy, Say
C INCLUDE:
c	include		't3d_array.h'
c	include		'sun.h'
C EXTERNAL:
	external	MapReadSRF
C SIDE EFFECTS:
C !!!!	Only the source surface field BR3D(*,*,1,*) and BT3D(*,*,1,*) is filled.
C	The rest of the array is not modified.
C RESTRICTIONS:
C	The temporary array Btmp must have at least 2*nLng*nLat elements
C	(nLng = # longitudes, nLat = # latitudes)
C PROCEDURE:
C	Using the mapreadt (instead of mapread) subroutine,
C	Either the Stanford potential field maps at a source surface of 2.5
C	Rsun, or the identically formatted maps out put from TJD's 
C	modification of Xuepu's IDL code, can be read in to fill in the source
C	surface of the BR3D array. Currently BT3D is not supported.
C
C	Note that the input array BR3D and BT3D are 4D arrays, i.e. 3 spatial dimensions
C	(longitude, latitude, radial distance) and one time dimension.
C MODIFICATION HISTORY:
C	DEC-2000, Paul Hick 	(UCSD; pphick@ucsd.edu)
C	SEP-2001, T Dunn 	(UCSD; tdunn@ucsd.edu)
C-
	character	cSay*10		/'T3D_readB'/
	real		BR3D(*),	!4D radial magnetic array whose SS will be filled
     &			BT3D(*),	!4D tangential magnetic array whose SS will not be filled
     &			Btmp(*)    	!scratch,filled by Mapreadt
 	real		XCbegMAT(*),    !3 Rotaion matrix of start-times
     &			XCendMAT(*),	!3 Rotaion matrix of end-times    
     &			XCbegROI(*),	!Start-times or region of interest
     &			XCendROI(*)	!End-times or region of interest

	real		XCadj(3)	/3*0./
		
	include		't3d_array.h'
	include		'sun.h'

	T3D_ReadBt = .True.		!may want to use this as a check
					!if "false", will print "no mag field data"


c TJD: use t3d_get instead of directly acessing t3d
	call t3d_iget(T3D__NLNG,0,nLng)
	call t3d_iget(T3D__NLAT,0,nLat)
	call t3d_iget(T3D__NRAD,0,nRad)
	call t3d_iget(T3D__NTIM,0,nTim)
	call t3d_iget(T3D__NCOFF,0,NCoff)


	if (T3D_ReadBt) then

	    Bad   = BadR4()

	    nLng1 = nLng-1
	    nLngLat = nLng*nLat
	    nLoc  = nLngLat*nRad
	    nLng2 = 1+2*nLngLat
C-------
C iLng is the number of longitudes in a single Carrington rotation.
C (here we assume XCbegROI to XCendROI cover exactly one rotation)

	    T3D_ReadBt = .FALSE.

	    L1 = 1-nLoc

	    do L=1,nTim	
	
		XCbeg = XCbegMAT(L)
		XCend = XCendMAT(L)
		
c		print *, 'XCendROI(L)',XCendROI(L)
c		print *, 'XCbegROI(L)',XCbegROI(L)
c		print *, 'XCend',XCend
c		print *, 'XCbeg',XCbeg
c		print *, 'nLng1',nLng1
c		print *, '(XCend-XCbeg)',(XCend-XCbeg)
c		print *, 'iLng should equal:',((XCendROI(L)-XCbegROI(L))/(XCend-XCbeg)*nLng1)+1

		iLng  = nint((XCendROI(L)-XCbegROI(L))/(XCend-XCbeg)*nLng1)+1
		iBlnk = 1
		
		XCbeg = NCoff+XCbeg
		XCend = NCoff+XCend

		L1 = L1+nLoc  


c* iLng would only be for a single rotation
c* Btmp is returned nLngLat in size	
		 
		print *, 'readbt - XCbeg,XCend',XCbeg,XCend	 
c		print *, ' XCadj',XCadj
c		print *, 'nLngLat',nLngLat
c		print *, 'iLng,nLat',iLng,nLat
	
c		print *, 'XCbeg,XCend',XCbeg,XCend
		
		call MapReadt(MapReadSRF,XCbeg,XCend,1,XCadj,0.,
     &		    nLngLat,iLng,nLat,Btmp,BR3D(L1),iBlnk,Bmin,Bmax)


		T3D_ReadBt = T3D_ReadBt .or. Bmin .ne. Bad
	
c TJD: The only holes should be at edges.
c		print *, 'Btmp(1)', Btmp(1)
c		print *, 'Btmp(2)', Btmp(2)
c		print *, 'Btmp(3)', Btmp(3)
c		print *, 'Btmp(300)', Btmp(300)
c		print *, 'Btmp(301)', Btmp(301)
c		print *, 'Btmp(302)', Btmp(302)
c		print *, 'Btmp(548)', Btmp(548)
c		print *, 'Btmp(549)', Btmp(549)
c		print *, 'Btmp(550)', Btmp(550)

c		call WhatisR4(nLat*nLng*3, Btmp,'Btmp info as follows')

		call ArrR4Copy(nLngLat,Btmp,BR3D(L1))
	
	    end do

		
	else
	    call Say(cSay,'W','RR','source surface for Stanford maps '//
     &		'is at 2.5 solar radii#no magnetic field data read')

	end if

	return
	end