def centroidInitialGuess(self,expNumber,star):
        '''
        Gets called for each exposure. If called on the first exposure, it will return
        the intial centroid guesses input by the DS9 regions file. If any other image
        and only one regions file has been submitted, it will return the previous centroid
        as the initial guess for subsequent exposures. If multiple regions files have been
        submitted, it will return the initial guesses in those regions files when the image path
        with index ``expNumber`` is equivalent to the path stored for that regions file's
        "Reference FITS image".

        Parameters
        ----------
        expNumber : int
            The index of the exposure currently being analyzed. The image gets called
            by its index from the list of image paths returned by getPaths().
        star : str
            The key from ``allStarsDict`` that corresponds to the star for which you'd
            like a centroid initial guess.

        Returns
        -------
        est_x : float
            Estimated centroid position of the star ``star`` along the *x*-axis of pixels for
            exposure index ``expNumber``

        est_y : float
            Estimated centroid position of the star ``star`` along the *y*-axis of pixels for
            exposure index ``expNumber``
        '''
        if expNumber == 0:
            est_x = self.allStarsDict[star]['x-pos'][0]  ## Use DS9 regions file's estimate for the
            est_y = self.allStarsDict[star]['y-pos'][0]  ##    stellar centroid for the first exposure
        elif self.imagesPaths[expNumber] in self.regionsFITSrefsList:
            refIndex = self.regionsFITSrefsList.index(self.imagesPaths[expNumber])
            init_x_list, init_y_list = self.parseRegionsFile(self.regionsFileList[refIndex])
            est_x = init_x_list[int(star)]
            est_y = init_y_list[int(star)]
        else:
            est_x = self.allStarsDict[star]['x-pos'][expNumber-1]    ## All other exposures use the
            est_y = self.allStarsDict[star]['y-pos'][expNumber-1]    ##    previous exposure centroid as estimate
        return est_x, est_y
dataset/ETHPy150Open OSCAAR/OSCAAR/oscaar/dataBank.py/dataBank.centroidInitialGuess/original