;Function findi.pro finds the index of a the first element of a given
;vector that has the given value.
;Use is as follows:
;             ind=findi(x,val,silent)
;Where
;    input       |      x = input vector
;                |    val = value to find index of in x
;                | silent = 1 for silent running, 0 otherwise
;
; optional input |silence = 0 for no displayed output, 1 otherwise
;
;   output       |    ind = index where val exists in x. If val is not an exact
;                           location the surrounding indicies are displayed if
;                           silence~=0, but ind will always equal the higher
;                           of the two surrounding indicies.
;Written as a matlab function by BWBerger circa 10/95
;Modified into an idl code by BWB on 4/16/99

function findi,x,val,silent

n=len(x)
found=0
if x(0) eq val then begin
   found=1
   ind=0
endif
i=1
while found eq 0 do begin
   if i ne n then begin
      if x(i) eq val then begin
         found=1
         ind=i
      endif else begin
         if x(i) gt val and x(i-1) lt val then begin
            found=2
            ind=i-1
         endif else begin
            if x(i) lt val and x(i-1) gt val then begin
               found=3
               ind=i-1
            endif
         endelse
      endelse
   endif else begin
      ind=-1
      found=4
   endelse
i=i+1
endwhile

if (silent eq 0) then begin
   if found eq 1 then begin
      print, 'Value found at index ',ind
   endif else begin
      if (found eq 2) or (found eq 3) then begin
         print,'Value is between index ',ind,' and ',ind+1
      endif else begin
         if found eq 4 then begin
            print, 'Value not found'
         endif
      endelse
   endelse
endif

return,ind
end