;+
;NAME:
;udata_interpolation
;
;PURPOSE:
; Perform the data interpolation for two time-serise data. 
;
;CALLING SEQUENCE:
; udata_interpolation, vname1,vname2
; 
;INPUT:
; vname1 = first tplot variable name
; vname2 = second tplot variable name
; 
;KEYWORDS:
;  st_time0  = start time of data interpolation
;  ed_time0 = end time of data interpolation
;  reverse = exchange of two data sets
;    If set, the data interplation is performed on the basis of time range of data2.
;  set_interval = set up time interval to interplate the two data sets.
;  If not set, the time interval is determined on the basis of the minimum interval
;  in the two data sets. 
;  
;EXAMPLE:
;   udata_interpolation, tplot1, tplot2
;
;CODE:
;R. Hamaguchi, 15/01/2013.
;
;MODIFICATIONS:
;A. Shinbori, 20/02/2013.
;
;ACKNOWLEDGEMENT:
; $LastChangedBy: nikos $
; $LastChangedDate: 2019-10-12 12:38:21 -0700 (Sat, 12 Oct 2019) $
; $LastChangedRevision: 27847 $
; $URL $
;-

pro udata_interpolation,vname1,vname2,$
    st_time0=st_time0,$
    ed_time0=ed_time0,$
    reverse=reverse,$
    set_interval=set_interval

;Get data from two tplot variables:
if strlen(tnames(vname1)) * strlen(tnames(vname2)) eq 0 then begin
  print, 'Cannot find the tplot vars in argument!'
  return
endif
get_data,vname1,data=d1
get_data,vname2,data=d2

time_01=d1.x
data_01=d1.y
time_02=d2.x
data_02=d2.y

;Exchange of two data sets:
if keyword_set(reverse) then begin
    if(rev eq 1) then begin
        tmpD=data_01
        tmpT=time_01
        data_01=data_02
        time_01=time_02
        data_02=tmpD
        time_02=tmpT
    endif
endif

s=''

for i=0L,n_elements(data_01)-1 do begin
    if finite(data_01[i]) then begin
        first01=i
        break
    endif
endfor
for i=0L,n_elements(data_01)-1 do begin
    if finite(data_01[n_elements(data_01)-1-i]) then begin
        last01=n_elements(data_01)-1-i
        break
    endif
endfor
for i=0L,n_elements(data_02)-1 do begin
    if finite(data_02[i]) then begin
        first02=i
        break
    endif
endfor
for i=0L,n_elements(data_02)-1 do begin
    if finite(data_02[n_elements(data_02)-1-i]) then begin
        last02=n_elements(data_02)-1-i
        break
    endif
endfor

st_time=max([time_01[first01],time_02[first02]])
ed_time=min([time_01[last01],time_02[last02]])

if keyword_set(st_time0) then begin
    if time_double(st_time0) ge st_time then st_time=time_double(st_time0)
endif 
if keyword_set(ed_time0) then begin
    if time_double(ed_time0) le ed_time then ed_time=time_double(ed_time0)
endif 
print,'Start Time : ',time_string(st_time)
print,'End Time : ',time_string(ed_time)
;st_timeとed_timeの幅内で初めて データが出た点をdata_01の開始点とする
;最終点もデータのある点にする

;================================================
;Determination of interval of data interpolation.
;If not set, it is the minimum time inverval.
;================================================
for i=1L,n_elements(data_01)-1 do begin
    append_array,interval,time_01[i]-time_01[i-1]
endfor

if keyword_set(set_interval) then begin
    itp_interval=set_interval
endif else begin
    itp_interval=min(interval)
endelse
print,itp_interval,'  [sec] : Time Interval'

i=0L
while (st_time+itp_interval*i le ed_time) do begin
    append_array,time_03,st_time+itp_interval*i
    i++
endwhile

inter_numX=0
inter_numY=0

flag2=0
tmp=!values.f_NAN
for i=0L,n_elements(time_03)-1 do begin
    if (where(time_01 eq time_03[i]) ne -1) then begin
        if finite(data_01[where(time_01 eq time_03[i])]) then begin
            append_array,data_03,data_01(where(time_01 eq time_03[i]))
            flag2=1
        endif
        ;if ~keyword_set(data_03) or (i eq n_elements(time_03)-1) then begin
        ;    flag2=1
        ;endif
    endif
    if (flag2 eq 0) then begin
        data_01l=data_01(where(time_01 lt time_03[i]))
        time_01l=time_01(where(time_01 lt time_03[i]))
        for j=1L,n_elements(data_01l) do begin
            if finite(data_01l[n_elements(data_01l)-j]) then begin
                inter_lowD=data_01l[n_elements(data_01l)-j]
                inter_lowT=time_01l[n_elements(data_01l)-j]
                break
            endif
        endfor
        data_01h=data_01[where(time_01 ge time_03[i])]
        time_01h=time_01[where(time_01 ge time_03[i])]
        for j=0L,n_elements(data_01h)-1 do begin
            if finite(data_01h[j]) then begin
                inter_highD=data_01h[j]
                inter_highT=time_01h[j]
                break
            endif
        endfor
        calA=double(inter_lowD)
        calB=double(inter_highD)-double(inter_lowD)
        calC=(double(time_03[i])-double(inter_lowT))/(double(inter_highT)-double(inter_lowT))
        append_array,data_03,calA+calB*calC
        inter_numX++
    endif
    flag2=0
endfor


flag2=0
for i=0L,n_elements(time_03)-1 do begin
    if (where(time_02 eq time_03[i]) ne -1) then begin
        if finite(data_02[where(time_02 eq time_03[i])]) then begin
            append_array,data_04,data_02[where(time_02 eq time_03[i])]
            flag2=1
        endif
        ;if ~keyword_set(data_04) or (i eq n_elements(time_03)-1) then begin
        ;    flag2=1
        ;endif
    endif
    if (flag2 eq 0) then begin
        data_02l=data_02[where(time_02 le time_03[i])]
        time_02l=time_02[where(time_02 le time_03[i])]
        for j=1L,n_elements(data_02l) do begin
            if finite(data_02l[n_elements(data_02l)-j]) then begin
                inter_lowD=data_02l[n_elements(data_02l)-j]
                inter_lowT=time_02l[n_elements(data_02l)-j]
                break
            endif
        endfor
        data_02h=data_02[where(time_02 gt time_03[i])]
        time_02h=time_02[where(time_02 gt time_03[i])]
        for j=0L,n_elements(data_02h)-1 do begin
            if finite(data_02h[j]) then begin
                inter_highD=data_02h[j]
                inter_highT=time_02h[j]
                break
            endif
        endfor
        calA=double(inter_lowD)
        calB=double(inter_highD)-double(inter_lowD)
        calC=(double(time_03[i])-double(inter_lowT))/(double(inter_highT)-double(inter_lowT))
        append_array,data_04,calA+calB*calC
        inter_numY++
    endif
    flag2=0
endfor

;print,'data04',n_elements(data_04),n_elements(data_03)
r_data=fltarr(n_elements(time_03),2)
for i=0L,n_elements(time_03)-1 do begin
    r_data[i,0]=float(data_03[i])
    r_data[i,1]=float(data_04[i])
endfor

;Store tplot variables:
store_data,vname1+'_interpol',data={x:time_03,y:r_data[*,0]}
store_data,vname2+'_interpol',data={x:time_03,y:r_data[*,1]}

tmp0=0
tmp1=0
;print,time_string(time_01),data_01
;for i=0,n_elements(data_01)-1 do begin
    ;print,time_string(time_1[i]),data_1[i],data_01[i],data_03[i]
;    if (finite(data_01[i])) and (finite(data_03[i])) then begin
;        tmp1=i
;    endif
;    if (tmp1 ne tmp0) then begin
 ;       append_array,span_data,time_01[tmp1]-time_01[tmp0]
        ;if time_01[tmp1]-time_01[tmp0] ne 3600 then print,tmp0,tmp1,time_string(time_01[tmp0]),time_string(time_01[tmp1]),data_01[tmp0],data_03[tmp0],data_01[tmp1],data_03[tmp1]
;        tmp0=tmp1
;    endif
;endfor
;print,span_data
;print,'-----------------interpolation status--------------------------------'
;print,'|                       number of all data     =',n_elements(data_01)
;print,'|            number of effective data pair     =',n_elements(span_data)+1
;minV=min(span_data)
;if minV le 0 then begin
;    idx=where(span_data gt 0)
;    minV=min(span_data[idx])
;endif
;print,'|            minimum time interval[second]     =',minV
;print,'|              maximum time interval / min     =',max(span_data)/minV
;print,'|              mean of time interval / min     =',mean(span_data)/minV
;print,'|standard deviation of time interval / min     =',stddev(span_data)/minV
;print,'---------------------------------------------------------------------'
;result=static_analysis_iugonet3(data_01,data_02)

print,n_elements(data_01),' : number of '+vname1+' data'
print,n_elements(data_02),' : number of '+vname2+' data'
print,n_elements(data_03),' : number of '+vname1+'_interpol '+'data (interpolated '+vname1+' data)'
print,n_elements(data_04),' : number of '+vname2+'_interpol '+'data (interpolated '+vname2+' data)'
print,inter_numX,' : interpolation number of '+vname1+'_interpol '+'data'
print,inter_numY,' : interpolation number of '+vname2+'_interpol '+'data'

;データの描画
;store_data,'sq_wind',data={x:time_01, y:data_03}
;         options,'sq_wind',ytitle='uwind[m/s]'
;window, 1, xsize=1100, ysize=700
;!p.multi=[0,1,4]
;plot,data_01,psym=0;,xticks = 4, xtickv = [time_string(time_01[0]),time_string(time_01[(n_elements(time_01)-1)/4]), time_string(time_01[(n_elements(time_01)-1)*2/4]),time_string(time_01[(n_elements(time_01)-1)*3/4]), time_string(time_01[n_elements(time_01)-1])];,xrange = [time_01[0],ed_time],ytitle='Res sq';,yrange = [-30,30]
;plot,data_03,yticks = 6;data_01,psym=0,xrange = [16600,17000], yrange = [-150,150];,xcharsize=1.25,ycharsize=1.25
;plot,data_02,psym=0;
;plot,data_04;data_02,psym=0,xrange = [100,500];,psym=7;


end