###################################################################################################
#  PRO ROCK, axis,SILENT = silent,FFAIL = ffail,TIME = tt, SETI0 = seti0, DTHETA = dx, NOREF = noref
#  Parameters: axis
###################################################################################################

def rock(axis = th1, ffail = False, tt = 0.2, seti0 = False, dx = None, noref = False):

    #Set MONOBEAM to negative value until rock succeeds
    #MONOBEAM channel used as token by ECX-feedback to stop corrections
    #until MONOBEAM NE -1      
    if !noref:
        caput('X06DA-OP-MO:MONOBEAM', -1 )
    e = get_energy()
    if dx is None:
        dx = 7.5e-2/e

    # reinforce theta1 and 2 setting (setting could be RDBD 0.0001 and RTRY 1 when seteq does not finish nicely)
    # put 'Retry deadband' to 0.00004 and 'Retries Max' to 5
    time.sleep(0.2)
    caput('X06DA-OP-MO1:ROX1.RDBD',0.00004)
    caput('X06DA-OP-MO1:ROX2.RDBD',0.00004)
    caput('X06DA-OP-MO1:ROX1.RTRY',5)
    caput('X06DA-OP-MO1:ROX2.RTRY',5)

    #time stamp
    print time.strftime('%X %x')

    #MVR,axis,-dx
    #SCAN,axis,0,2*dx,20,/fit,/centre,SILENT = silent,FFAIL = ffail,time=tt,/deriv,$
    #data=d
    axis_pos = axis.read()
    result = lscan(axis, beam_ref, -dx, dx, 20, latency = 0.3, relative = True, context = None, before_read = None, after_read = None)
    (ydata, xdata) = (result.getReadable(0), result.getPositions(0))
    (norm, mean, sigma) = fit(ydata, xdata) 
    if (mean is not None) and (mean <= (axis_po + dx))  and  (mean >= (axis_po - dx)):
        caput(axis, mean)
    else:
        print 'fit failed - centering on maximum'
        max_x= xdata[ydata.index(max(ydata))]        
        caput(axis, max_x)
    

    if seti0 and not ffail:
        time.sleep(2)
        run("setI0")
        
    #add after_rock BPM1:SUM as reference for monitoring monochromator thermal drift
    if (noref==False) and not ffail:
        time.sleep(3) # wait a bit until mono theta finish moving        
        caput('X06DA-OP-MO:MONOBEAM', beam_ref)
        print 'rock_success new mono beam at ' + str(beam_ref.read()) + ' at' + str(e) + ' keV'



rock(rock_axis)