;*********************************************************
;  Need to calculate the center lat and lon of the 
;  bounding box.  This can be tricky.
;*********************************************************

pro center_lat_lon,lat_min,lon_min,lat_max,lon_max,$
  clat,clon

;  In case the lon max and min cross the -180/180 line, 
;  create a lon max and min that is continuously
;  increasing. Mainly used for twp plots.  
;  To convert to continous increasing: where lon < 0, +360
;  To convert back to standard lon   : where lon > 180, -360

if lon_min lt 0 then lon_min_cont=lon_min+360 else lon_min_cont=lon_min
if lon_max lt 0 then lon_max_cont=lon_max+360 else lon_max_cont=lon_max

;  Calculate the center lon and then adjust for the 
;  conversion to continuously increasing lon

clon=(lon_min_cont+lon_max_cont)/2.0
if clon gt 180 then clon=clon-360

;  Calculate the center lat
  
clat=(lat_min+lat_max)/2.0

return
end