;;;;GRAT_START;;;;

Common grat_vars,en1,en2,en3,type,hmax,wmax,period,z,en1eff,en2eff,en3eff

hc=12.399                                     ;;;;units of keV*Angstroms
n=1e4                                         ;;;;number of elements in array
cell=complexarr(n)                            ;;;;grating array 
orders=indgen(10000)/50.                      ;;;;due to period=200 impulses
order=n/200                                   ;;;;based on period=200 impulses
first=order & second=2*order & third=3*order  ;;;;diffraction orders
type='' & lean='' & trap='' & squar='' & convol=''

read,'What three x-ray energies (keV)? ',en1,en2,en3
read,'What is maximum height of bars (angstroms)? ',hmax
read,'What period between bars (angstroms)? ',period
read,'What is maximum width of bars (angstroms)? ',wmax
while type NE 'g' and type NE 's' do read,'Gold or Silver grating(g/s)? ',type

k1=en1*2.0*!pi/hc & k2=en2*2.0*!pi/hc & k3=en3*2.0*!pi/hc

print,'ENTER ANGLES TO GIVE EQUAL MAGNITUDES OF LEANING RANGE FOR GRATING BARS.'
read,'What is beginning angle of lean for first bar (degrees)? ',anglemin1
read,'What is ending angle of lean for first bar (degrees)? ',anglemax1
tryagain:    
read,'What is beginning angle of lean for second bar (degrees)? ',anglemin2
read,'What is ending angle of lean for second bar (degrees)? ',anglemax2
if abs(anglemax2-anglemin2) NE abs(anglemax1-anglemin1) then begin
  print,'!!! Range not same as first bar !!!'
  goto,tryagain
endif
read,'Step by how many degrees between min and max angles? ',anglestep

angles=float(indgen((abs(anglemax1-anglemin1)/anglestep)+1))*anglestep
if anglemax1 GT anglemin1 then angles1=angles+anglemin1 else $
  angles1=anglemin1-angles
if anglemax2 GT anglemin2 then angles2=angles+anglemin2 else $
  angles2=anglemin2-angles
print,'Angles for first bar: ',angles1 & print,''
print,'Angles for second bar: ',angles2
dum=size(angles) 
numangles=dum(1)
en1eff=fltarr(numangles,4)                    ;;;;efficiencies at the three
en2eff=fltarr(numangles,4)                    ;;;;energies: columns=angles
en3eff=fltarr(numangles,4)                    ;;;;and rows=orders

FOR a=0,(numangles-1) DO BEGIN  ;;*********************************
angle1=angles1(a) & angle2=angles2(a)
grat_lean_range,angle1,angle2

FOR i=1,3 DO BEGIN              ;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  
if i eq 1 then begin & en=en1 & k=k1 & endif
if i eq 2 then begin & en=en2 & k=k2 & endif
if i eq 3 then begin & en=en3 & k=k3 & endif
index=getdeltabeta(en,type)
delta=index(0) & beta=index(1)

realcell=(-k*beta*z)  
imcell=(k*delta*z)
compcell=complex(realcell,imcell)  
expcell=exp(compcell)
cell(0:399)=expcell
fcell=fft(cell,-1)

if i eq 1 then fcell1=fcell 
if i eq 2 then fcell2=fcell 
if i eq 3 then fcell3=fcell 

norm=(n/400)^2       ;;;;normalization of intensities because fft divides 
                     ;;;;by #elements and must divide ftransform by cell width 

;if i eq 1 then !p.multi=[0,1,3] else $  ;;;;this is necessary to plot images
;!p.multi=[4-i,1,3]                      ;;;;in order from top to bottom 

;plot,orders,(abs(fcell))^2*norm,xr=[0,6],charsize=2,$
;      xtitle='ORDER',ytitle='INTENSITY',title=en

ENDFOR                         ;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 

en1eff(a,0)=abs(fcell1(0))^2*norm         ;;;;these efficiences are based
en1eff(a,1)=abs(fcell1(first))^2*norm     ;;;;on the orders found when the
en1eff(a,2)=abs(fcell1(second))^2*norm    ;;;;bars are spaced apart by 200
en1eff(a,3)=abs(fcell1(third))^2*norm     ;;;;exactly as determined by the
en2eff(a,0)=abs(fcell2(0))^2*norm         ;;;;impulse function distribution
en2eff(a,1)=abs(fcell2(first))^2*norm
en2eff(a,2)=abs(fcell2(second))^2*norm
en2eff(a,3)=abs(fcell2(third))^2*norm
en3eff(a,0)=abs(fcell3(0))^2*norm
en3eff(a,1)=abs(fcell3(first))^2*norm
en3eff(a,2)=abs(fcell3(second))^2*norm
en3eff(a,3)=abs(fcell3(third))^2*norm
;;print,'en1: ',en1eff(a,*)
;;print,'en2: ',en2eff(a,*)
;;print,'en3: ',en3eff(a,*)
ENDFOR ;;*********************************

grat_eff_plot

END