chx_generic_functions.py 文件源码

def get_fra_num_by_dose( exp_dose, exp_time, att=1, dead_time =2 ):
    '''
    Calculate the frame number to be correlated by giving a X-ray exposure dose

    Paramters:
        exp_dose: a list, the exposed dose, e.g., in unit of exp_time(ms)*N(fram num)*att( attenuation)
        exp_time: float, the exposure time for a xpcs time sereies
        dead_time: dead time for the fast shutter reponse time, CHX = 2ms
    Return:
        noframes: the frame number to be correlated, exp_dose/( exp_time + dead_time )  
    e.g.,

    no_dose_fra = get_fra_num_by_dose(  exp_dose = [ 3.34* 20, 3.34*50, 3.34*100, 3.34*502, 3.34*505 ],
                                   exp_time = 1.34, dead_time = 2)

    --> no_dose_fra  will be array([ 20,  50, 100, 502, 504])     
    '''
    return np.int_(    np.array( exp_dose )/( exp_time + dead_time)/ att )