Exemplo n.º 1
0
def do_circular_photometry(data,
                           positions,
                           radius,
                           effective_gain,
                           method,
                           subpixels,
                           r_in=None):

    extents = np.zeros((len(positions), 4), dtype=int)
    extents[:, 0] = positions[:, 0] - radius + 0.5
    extents[:, 1] = positions[:, 0] + radius + 1.5
    extents[:, 2] = positions[:, 1] - radius + 0.5
    extents[:, 3] = positions[:, 1] + radius + 1.5

    ood_filter, extent, phot_extent = get_phot_extents(data, positions,
                                                       extents)

    flux = np.zeros(len(positions), dtype=np.float)

    # TODO: flag these objects
    if np.sum(ood_filter):
        flux[ood_filter] = np.nan
        warnings.warn(
            "The aperture at position {0} does not have any "
            "overlap with the data".format(positions[ood_filter]),
            AstropyUserWarning)
        if np.sum(ood_filter) == len(positions):
            return (flux, )

    x_min, x_max, y_min, y_max = extent
    x_pmin, x_pmax, y_pmin, y_pmax = phot_extent

    if method == 'center':
        use_exact = 0
        subpixels = 1
    elif method == 'subpixel':
        use_exact = 0
    else:
        use_exact = 1
        subpixels = 1

    for i in range(len(flux)):
        if not np.isnan(flux[i]):
            fraction = circular_overlap_grid(x_pmin[i], x_pmax[i], y_pmin[i],
                                             y_pmax[i], x_max[i] - x_min[i],
                                             y_max[i] - y_min[i], radius,
                                             use_exact, subpixels)

            if r_in is not None:
                fraction -= circular_overlap_grid(x_pmin[i], x_pmax[i],
                                                  y_pmin[i], y_pmax[i],
                                                  x_max[i] - x_min[i],
                                                  y_max[i] - y_min[i], r_in,
                                                  use_exact, subpixels)

            flux[i] = np.sum(data[y_min[i]:y_max[i], x_min[i]:x_max[i]] *
                             fraction)

    return (flux, )
Exemplo n.º 2
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def time_circular_big_subpixel_5():
    circular_overlap_grid(-4.,
                          4.,
                          -4.,
                          4.,
                          100,
                          100,
                          3.,
                          use_exact=1,
                          subpixels=5)
Exemplo n.º 3
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def time_circular_small_exact():
    circular_overlap_grid(-4.,
                          4.,
                          -4.,
                          4.,
                          10,
                          10,
                          3.,
                          use_exact=1,
                          subpixels=1)
Exemplo n.º 4
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def do_circular_photometry(data, positions, radius, effective_gain,
                           method, subpixels, r_in=None):


    extents = np.zeros((len(positions), 4), dtype=int)
    extents[:,0] = positions[:,0] - radius + 0.5
    extents[:,1] = positions[:,0] + radius + 1.5
    extents[:,2] = positions[:,1] - radius + 0.5
    extents[:,3] = positions[:,1] + radius + 1.5

    ood_filter, extent, phot_extent = get_phot_extents(data, positions, extents)

    flux = np.zeros(len(positions), dtype=np.float)

    # TODO: flag these objects
    if np.sum(ood_filter):
        flux[ood_filter] = np.nan
        warnings.warn("The aperture at position {0} does not have any "
                      "overlap with the data"
                      .format(positions[ood_filter]),
                      AstropyUserWarning)
        if np.sum(ood_filter) == len(positions):
            return (flux, )

    x_min, x_max, y_min, y_max = extent
    x_pmin, x_pmax, y_pmin, y_pmax = phot_extent

    if method == 'center':
        use_exact = 0
        subpixels = 1
    elif method == 'subpixel':
        use_exact = 0
    else:
        use_exact = 1
        subpixels = 1

    for i in range(len(flux)):
        if not np.isnan(flux[i]):
            fraction = circular_overlap_grid(x_pmin[i], x_pmax[i],
                                             y_pmin[i], y_pmax[i],
                                             x_max[i] - x_min[i],
                                             y_max[i] - y_min[i],
                                             radius, use_exact, subpixels)

            if r_in is not None:
                fraction -= circular_overlap_grid(x_pmin[i], x_pmax[i],
                                                  y_pmin[i], y_pmax[i],
                                                  x_max[i] - x_min[i],
                                                  y_max[i] - y_min[i],
                                                  r_in, use_exact, subpixels)

            flux[i] = np.sum(data[y_min[i]:y_max[i],
                                  x_min[i]:x_max[i]] * fraction)

    return (flux, )
Exemplo n.º 5
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def remove_concentric(data, x_mean=512, y_mean=512, x_stddev=3, y_stddev=3, Nsig=10, dp=0.1):
    """
    This function first fits a gaussian PSF to the data to find the centroid.
    Then, it subtracts concentric apertures from the data rather than just 
    subtracting the gaussian model.
    """
    data = data.copy() # Don't overwrite the data
    nx, ny = data.shape
    
    gauss, psf, centroid = fit_gaussian_psf(data, x_mean=x_mean, y_mean=y_mean, 
                                          x_stddev=x_stddev, y_stddev=y_stddev)
    std = (gauss.x_stddev_0.value + gauss.y_stddev_0.value)/2.0
    x0, y0 = centroid
    
    radii = np.arange(dp, Nsig*std, dp)[::-1]
    
    # Get extents using the photutils function
    pos = np.atleast_2d(centroid)
    extents = np.zeros((len(pos), 4), dtype=int)

    extents[:, 0] = pos[:, 0] - max(radii) + 0.5
    extents[:, 1] = pos[:, 0] + max(radii) + 1.5
    extents[:, 2] = pos[:, 1] - max(radii) + 0.5
    extents[:, 3] = pos[:, 1] + max(radii) + 1.5

    _, extent, phot_extent = get_phot_extents(data, pos, extents)
    x_min, x_max, y_min, y_max = extent
    x_pmin, x_pmax, y_pmin, y_pmax = phot_extent
    args = [x_pmin[0], x_pmax[0], y_pmin[0], y_pmax[0], x_max[0]-x_min[0], y_max[0]-y_min[0]]

    # Fit apertures
    psf = np.zeros(data.shape)
    for radius in radii:
        Rin = radius - dp
        Rout = radius
        if Rin > dp/10.0:
            ap = CircularAnnulus(centroid, r_in=Rin, r_out=Rout)
        else:
            ap = CircularAperture(centroid, r=Rout)
        phot = aperture_photometry(data, ap)
        avg_flux = phot['aperture_sum'].item()/ap.area()
        
        outer = circular_overlap_grid(*args, r=Rout, use_exact=1, subpixels=5)
        if Rout-dp > dp/10.0:
            inner = circular_overlap_grid(*args, r=Rin, use_exact=1, subpixels=5)
        else:
            inner = 0.0
        annulus_overlap = outer - inner
        psf[y_min[0]:y_max[0], x_min[0]:x_max[0]] += annulus_overlap * avg_flux
    return data - psf, psf, np.array(centroid)
Exemplo n.º 6
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    def to_mask(self, x_size, y_size):
        """
        This function ...
        :param x_size:
        :param y_size:
        :return:
        """

        rel_center = self.center

        x_min = -rel_center.x
        x_max = x_size - rel_center.x
        y_min = -rel_center.y
        y_max = y_size - rel_center.y

        fraction = circular_overlap_grid(x_min,
                                         x_max,
                                         y_min,
                                         y_max,
                                         x_size,
                                         y_size,
                                         self.radius,
                                         use_exact=0,
                                         subpixels=1)

        #from ..tools import plotting
        #plotting.plot_mask(fraction)

        # Return a new mask
        return Mask(fraction)
Exemplo n.º 7
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    def circular_mask(self, radius, xoff=0.0, yoff=0.0, use_exact=1, subsampling=1, transparency=1.0):
        """
        Define a circular mask within the grid of a specified radius and offset by xoff/yoff.
        Use photutils.geometry to create masks that calculate the fraction of a pixel subtended
        by the circular mask.  use_exact=1 performs the exact geometric calculation while
        use_exact=0 will sub-sample the pixels by the specfied subsampling parameter
        to estimate the subtended area.

        Parameters
        ----------
        radius: float
            Radius of the circular mask
        xoff: float
            X position of the center of the mask
        yoff: float
            Y position of the center of the mask
        use_exact: int (default: 1)
            If 1, then use exact geometrical calculation to weight pixels partially covered by mask.
            This parameter is passed directly on to photutils.geometry.circular_overlap_grid()
        subsampling: int (default: 1)
            If use_exact=0, then subsample pixels by this factor to calculate area of each pixel subtended
            by the mask. The default value of 1 will force no partial pixels to be included in the mask.
            This parameter is passed directly on to photutils.geometry.circular_overlap_grid()
        transparency: float (default: 1.0)
            Transparency of the mask
        Returns
        -------
        mask: 2D np.ndarray
            2D mask image
        """
        if transparency < 0.0 or transparency > 1.0:
            msg = "Mask transparency, %f, must be in the range of 0.0 (fully opaque) to 1.0 (fully clear)." % transparency
            raise EngineInputError(value=msg)

        t = self.as_dict()
        # we need to use flipud because we use an origin in the UL corner of an image
        # while photutils uses the LL corner.
        mask = np.flipud(
            circular_overlap_grid(
                t['x_min'] - xoff,
                t['x_max'] - xoff,
                t['y_min'] - yoff,
                t['y_max'] - yoff,
                t['x_size'],
                t['y_size'],
                radius,
                use_exact,
                subsampling
            )
        )
        mask *= transparency
        return mask
def get_circular_overlap(*args, **kwargs):
    global grid_cache

    key = list(args)
    for arg in ['r', 'use_exact', 'subpixels']:
        key.append(kwargs[arg])
    key = tuple(key)
    try:
        retval = grid_cache[key]
    except KeyError:
        retval = circular_overlap_grid(*args, **kwargs)
        #grid_cache[key] = retval
    return retval
Exemplo n.º 9
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def circular_photometry_weights(data, positions, radius):
    """
    Return an array of weights corresponding to a circular aperture.

    Parameters 
    ----------
    data : Not used in computation. Just for shape info
    positions : (x,y) position of flux center recal x = column, y = rows
    """

    extents = np.zeros((len(positions), 4), dtype=int)
    extents[:, 0] = positions[:, 0] - radius + 0.5
    extents[:, 1] = positions[:, 0] + radius + 1.5
    extents[:, 2] = positions[:, 1] - radius + 0.5
    extents[:, 3] = positions[:, 1] + radius + 1.5

    ood_filter, extent, phot_extent = get_phot_extents(data, positions,
                                                       extents)
    weights = np.zeros(data.shape)

    # TODO: flag these objects
    if np.sum(ood_filter):
        flux[ood_filter] = np.nan
        warnings.warn(
            "The aperture at position {0} does not have any "
            "overlap with the data".format(positions[ood_filter]),
            AstropyUserWarning)
        if np.sum(ood_filter) == len(positions):
            return (flux, )

    x_min, x_max, y_min, y_max = extent
    x_pmin, x_pmax, y_pmin, y_pmax = phot_extent

    use_exact = 1
    subpixels = 1

    fraction = circular_overlap_grid(x_pmin, x_pmax, y_pmin, y_pmax,
                                     x_max - x_min, y_max - y_min, radius,
                                     use_exact, subpixels)

    yslice = slice(y_min[0], y_max[0])
    xslice = slice(x_min[0], x_max[0])
    weights[yslice, xslice] = fraction
    return weights
Exemplo n.º 10
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def circular_photometry_weights(data, positions, radius):
    """
    Return an array of weights corresponding to a circular aperture.

    Parameters 
    ----------
    data : Not used in computation. Just for shape info
    positions : (x,y) position of flux center recal x = column, y = rows
    """

    extents = np.zeros((len(positions), 4), dtype=int)
    extents[:,0] = positions[:,0] - radius + 0.5
    extents[:,1] = positions[:,0] + radius + 1.5
    extents[:,2] = positions[:,1] - radius + 0.5
    extents[:,3] = positions[:,1] + radius + 1.5

    ood_filter, extent, phot_extent = get_phot_extents(data, positions, extents)
    weights = np.zeros(data.shape)

    # TODO: flag these objects
    if np.sum(ood_filter):
        flux[ood_filter] = np.nan
        warnings.warn("The aperture at position {0} does not have any "
                      "overlap with the data"
                      .format(positions[ood_filter]),
                      AstropyUserWarning)
        if np.sum(ood_filter) == len(positions):
            return (flux, )

    x_min, x_max, y_min, y_max = extent
    x_pmin, x_pmax, y_pmin, y_pmax = phot_extent

    use_exact = 1
    subpixels = 1

    fraction = circular_overlap_grid(
        x_pmin, x_pmax, y_pmin, y_pmax, x_max - x_min, y_max - y_min, radius, 
        use_exact, subpixels)

    yslice = slice(y_min[0],y_max[0])
    xslice = slice(x_min[0],x_max[0])
    weights[yslice,xslice] = fraction
    return weights
Exemplo n.º 11
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    def to_mask(self, x_size, y_size):

        """
        This function ...
        :param x_size:
        :param y_size:
        :return:
        """

        rel_center = self.center

        x_min = - rel_center.x
        x_max = x_size - rel_center.x
        y_min = - rel_center.y
        y_max = y_size - rel_center.y

        fraction = circular_overlap_grid(x_min, x_max, y_min, y_max, x_size, y_size, self.radius, use_exact=0, subpixels=1)

        # Return a new mask
        return Mask(fraction)
Exemplo n.º 12
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def calc_masked_aperture(ap, image, method='mmm', mask=None):

    positions = ap.positions
    extents = np.zeros((len(positions), 4), dtype=int)
    
    if isinstance(ap, EllipticalAnnulus):
        radius = ap.a_out
    elif isinstance(ap, CircularAnnulus):
        radius = ap.r_out
    elif isinstance(ap, CircularAperture):
        radius = ap.r
    elif isinstance(ap, EllipticalAperture):
        radius = ap.a
    
    extents[:, 0] = positions[:, 0] - radius + 0.5
    extents[:, 1] = positions[:, 0] + radius + 1.5
    extents[:, 2] = positions[:, 1] - radius + 0.5
    extents[:, 3] = positions[:, 1] + radius + 1.5
    
    ood_filter, extent, phot_extent = get_phot_extents(image, positions,
                                                       extents)
    
    x_min, x_max, y_min, y_max = extent
    x_pmin, x_pmax, y_pmin, y_pmax = phot_extent
    
    bkg = np.zeros(len(positions))
    area = np.zeros(len(positions))
    
    for i in range(len(bkg)):
        if isinstance(ap, EllipticalAnnulus):
            fraction = elliptical_overlap_grid(x_pmin[i], x_pmax[i],
                                               y_pmin[i], y_pmax[i],
                                               x_max[i] - x_min[i],
                                               y_max[i] - y_min[i],
                                               ap.a_out, ap.b_out, ap.theta, 0,
                                               1)
            b_in = ap.a_in * ap.b_out / ap.a_out
            fraction -= elliptical_overlap_grid(x_pmin[i], x_pmax[i],
                                                y_pmin[i], y_pmax[i],
                                                x_max[i] - x_min[i],
                                                y_max[i] - y_min[i],
                                                ap.a_in, b_in, ap.theta,
                                                0, 1)
        elif isinstance(ap, CircularAnnulus):
            fraction = circular_overlap_grid(x_pmin[i], x_pmax[i],
                                             y_pmin[i], y_pmax[i],
                                             x_max[i] - x_min[i],
                                             y_max[i] - y_min[i],
                                             ap.r_out, 0, 1)
            
            fraction -= circular_overlap_grid(x_pmin[i], x_pmax[i],
                                                y_pmin[i], y_pmax[i],
                                                x_max[i] - x_min[i],
                                                y_max[i] - y_min[i],
                                                ap.r_in, 0, 1)
        elif isinstance(ap, CircularAperture):
            fraction = circular_overlap_grid(x_pmin[i], x_pmax[i],
                                             y_pmin[i], y_pmax[i],
                                             x_max[i] - x_min[i],
                                             y_max[i] - y_min[i],
                                             ap.r, 0, 1) 
        
        elif isinstance(ap, EllipticalAperture):
            fraction = elliptical_overlap_grid(x_pmin[i], x_pmax[i],
                                               y_pmin[i], y_pmax[i],
                                               x_max[i] - x_min[i],
                                               y_max[i] - y_min[i],
                                               ap.a, ap.b, ap.theta, 0,
                                               1)
        
        pixel_data = image[y_min[i]:y_max[i], x_min[i]:x_max[i]] * fraction
        if mask is not None:
            pixel_data[mask[y_min[i]:y_max[i], x_min[i]:x_max[i]]] = 0.0
        
        good_pixels = pixel_data[pixel_data != 0.0].flatten()
        
        if method == 'mmm':
            skymod, skysigma, skew = mmm(good_pixels)
            bkg[i] = skymod
        elif method == 'sum':
            bkg[i] = np.sum(good_pixels)
        elif method == 'max':
            bkg[i] = np.nanmax(good_pixels)
        area[i] = len(good_pixels)

    return bkg, area
Exemplo n.º 13
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def fpf_calculator(image,filetype,planet_position,radius,method='exact',subpix=20,plot=False,
                 no_planet_nghbr=True,name='fpf_test',save='False',save_dir='None', j=None):


    ####### PARAMETERS:
    ## image : fits OR 2d-array : (PynPointed) image where to perform the SNR & FPF calculation (as an array or a single fits file)
                                # n.b.: during the whole analysis the image is assumed to be centered on the central star.
    ## filetype : string : format of the image. Possibilities are: 'fits' or 'array'
    ## planet_position : array of two values : rough position of the target in (integer) pixels, as an array: [x,y] (n.b.: if the
                                                #  'method' is 'exact' this position will be assumed to be the best position)
    ## radius : float : desired radius for the apertures (in pixels)
    ## method : string : how to search for the best position given the rough one. Possibilities are:
                        # 'exact' : the given planet_position is assumed to be the best one
                        # 'search' : the best position is found performing a search for the local maximum pixel value
                        # around the given planet_position in a square of side = (2 * r) * 2, rounded up
                        # (nb: the best position is found as integer pixels)
                        # 'fit' : the best position is found fitting a 2D gaussian on the given planet_position. The best
                        # position found in this way allows for floating pixels values.
    ## subpix : integer : how much refined the subpixel grid for the creation of the aperture should be. Each pixel is resampled in
                        #  subpix*subpix other pixels. (Quick test showed that after a value of 10-15, the final results are
                        # quite stable, so the default is 20).
    ## plot : boolean : whether to plot or not the final image together with the created apertures, the SNR and the FPF value
    ## no_planet_nghbr : boolean : whether to consider or not the two background apertures near the signal aperture.
    ## name : string : desired name with which save the final result (if save==True).
    ## save : boolean : whether or not save the results. If true, two images will be saved as fits files: the initial image
                        # with the apertures, and the initial image plus the gaussian fit.
    ## save_dir : string : path to a folder where to save (if save==True) the images as fits files

    ##### OUTPUT:
    ## the function returns:
    # fpf : float : value of the False Probability Fraction evaluated from the t_test value
    # t_test : float : value of the t_test
    # snr : float : value of the snr
    # planet_pos : array of two values : best planet position (evaluated with the desired method) in pixels
    # bckg_aps_cntr : multidimensional array : it contains (in pixel values) all the centers of ALL the apertures created
                    # for the analysis (including the signal aperture and the two apertures nearby). n.b.: the last is the
                    # center position of the signal aperture, i.e.: the best position (found with the desired method)
    # fpf_bckgs : array : it contains the FPF values evaluated for all the background apertures with respect to each other.
                        # n.b.: the signal aperture is ALWAYS excluded, while the background apertures nearby are excluded only if requested

    ## if method == 'fit', it also returns:
    # popt : array : best fit parameters found for the 2D gaussian fit (amplitude, xo, yo, sigma_x, sigma_y, theta, offset)
    # pcov : 2d array : the estimated covariance of popt as returned by the function scipy.optimize.curve_fit

    #############################################


    #Let's import the image:
    if filetype=='fits':
        data=fits.open(image)[0].data #NB: the fits file must consist of a single image (NO datacube)!
    if filetype=='array':
        data=image

    #Get the image size:
    size = len(data[0])

    #Define the center (i.e.: the image is supposed to be centered on the central star):
    center=np.array([size/2.,size/2.])

    #Round up the size of the range of search for the local maximum:
    ros=math.ceil(radius)#*2) #* 2.
    print 'ROS ',ros

    #Let's find the planet position:
    if method =='exact':
        planet_pos=planet_position
    if method == 'search':
        planet_pos=planets_finder(data,'array','local_max',planet_position=planet_position,range_of_search=ros)[0]
    if method == 'fit':
        planet_pos_guess=planets_finder(data,'array','local_max',planet_position=planet_position,range_of_search=ros)[0]
        #Create grid for the fit:
        x = range(size)
        y = range(size)
        x, y = np.meshgrid(x, y)
        sigma = (radius*2)/(2.*np.sqrt(2.*np.log(2.)))
        #create arrays of initial guess:
        #See which quadrant the planet is in, and give accordingly the correct additional factor for the arctan calculation:
        if planet_position[0]>= size/2. and planet_position[1]>=size/2.: #first quadrant
            arctan_fac=0.
            angle_factor=90.
        if planet_position[0]<=size/2. and planet_position[1]>=size/2.:#second quadrant
            arctan_fac=180.
            angle_factor=360.+90.
        if planet_position[0]<=size/2. and planet_position[1]<=size/2.:#third quadrant
              arctan_fac=180.
              angle_factor=270.+180.
        if planet_position[0]>=size/2. and planet_position[1]<=size/2.:#fourth quadrant
            arctan_fac=360.
            angle_factor=180.+270.

        theta=np.deg2rad(angle_factor-(np.degrees(np.arctan((planet_position[1] - size/2.)/(planet_position[0] - size/2.))) + arctan_fac))

        p0=[data[planet_pos_guess[1]][planet_pos_guess[0]],planet_pos_guess[0],planet_pos_guess[1],sigma,sigma,theta,0.]
        print '\n\ninitial guess : '+str(p0)
        popt, pcov = opt.curve_fit(twoD_Gaussian, (x, y), data.flatten(),p0=p0)
        planet_pos=np.array([popt[1],popt[2]])
        data_fitted=twoD_Gaussian((x,y),*popt)
        print popt
#[planet_pos_guess[0]-5:planet_pos_guess[0]+5, planet_pos_guess[1]-5:planet_pos_guess[1]+5]
    #let's calculate the distance between the planet and the star (i.e.: ASSUMING IMAGE CENTERING):
    d=np.sqrt((planet_pos[0] - center[0])**2 + (planet_pos[1]-center[1])**2)

    #Now, starting from the position of the planet, let's create a series of background apertures:

    #Let's calculate how many apertures can I put at that distance and given a certain radius of the aperture:
    n_bckg_aps=np.int((2*np.pi*d)/(2.*radius)) #NB: np.int assures that the number is rounded down to avoid overlaps

    #Let's save the center positions of all the background apertures:
    bckg_aps_cntr=np.ones((n_bckg_aps,2))
    angle_i=360./n_bckg_aps
    for i_apertures in range(0,n_bckg_aps):
        bckg_aps_cntr[i_apertures]=angular_coords_float(center,planet_pos,angle_i)
        angle_i=angle_i+(360./(n_bckg_aps))

    #Define the area (given the radius):
    area= np.pi * radius**2

    #Create the apertures and calculate the weighted pixel values in all of them: (the LAST one is the signal aperture)

    #Define some void arrays to be filled with the flux inside each aperture (i.e.: sum of all the weighted pixels),
    # the single weighted pixel values for all the apertures, the fractions for to be multiplied for all the apertures
    # and the not-weighted pixel values:
    # flux = np.zeros(len(bckg_aps_cntr), dtype=np.float)
    fractions=[]
    bckg_values=[]
    bckg_apertures=[]
    signal_aperture=[]

    #Let's define the extention of the region of interest for each aperture
    extents = np.zeros((len(bckg_aps_cntr), 4), dtype=int)

    extents[:, 0] = bckg_aps_cntr[:, 0] - radius + 0.5
    extents[:, 1] = bckg_aps_cntr[:, 0] + radius + 1.5
    extents[:, 2] = bckg_aps_cntr[:, 1] - radius + 0.5
    extents[:, 3] = bckg_aps_cntr[:, 1] + radius + 1.5

    ood_filter, extent, phot_extent = get_phot_extents(data, bckg_aps_cntr,extents)

    x_min, x_max, y_min, y_max = extent
    x_pmin, x_pmax, y_pmin, y_pmax = phot_extent

    if no_planet_nghbr==True:
        print 'Ignore the two apertures near the signal aperture'
    #For each aperture, let's calculate the fraction values given by the intersection between the pixel region of interest
    # and a circle of radius r, then use these fractions to evaluate the final weighted pixel values for each aperture:
    for index in range(len(bckg_aps_cntr)):
        fraction= geometry.circular_overlap_grid(x_pmin[index], x_pmax[index],
                                                  y_pmin[index], y_pmax[index],
                                                  x_max[index] - x_min[index],
                                                  y_max[index]- y_min[index],
                                                  radius, 0, subpix)
        fractions.append(fraction)

        #now, let's return the weighted pixel values but erasing the values ==0. (since the subpixel sampling can result
        # in a fraction =0 and so the pixel value is weighted by 0. and so it is =0. But it is not really 0.)

        #Ignore, if requested, the two apertures near the signal aperture:
        if no_planet_nghbr==True:
            if index != len(bckg_aps_cntr)-1 and index != len(bckg_aps_cntr)-2 and index != 0:
                bckg_values += (filter(lambda a: a !=0.,np.array((data[y_min[index]:y_max[index],x_min[index]:x_max[index]] * fraction)).ravel()))
                bckg_apertures.append(filter(lambda a: a !=0.,np.array((data[y_min[index]:y_max[index],x_min[index]:x_max[index]] * fraction)).ravel()))

            if index==len(bckg_aps_cntr)-1:
                signal_aperture += (filter(lambda a: a !=0.,np.array((data[y_min[index]:y_max[index],x_min[index]:x_max[index]] * fraction)).ravel()))

        else:
            if index != len(bckg_aps_cntr)-1:
                bckg_values += (filter(lambda a: a !=0.,np.array((data[y_min[index]:y_max[index],x_min[index]:x_max[index]] * fraction)).ravel()))
                bckg_apertures.append(filter(lambda a: a !=0.,np.array((data[y_min[index]:y_max[index],x_min[index]:x_max[index]] * fraction)).ravel()))

            else:
                signal_aperture += (filter(lambda a: a !=0.,np.array((data[y_min[index]:y_max[index],x_min[index]:x_max[index]] * fraction)).ravel()))

    signal_aperture=np.array(signal_aperture)
    bckg_values=np.array(bckg_values)
    bckg_apertures=np.array(bckg_apertures)

    ##################################################################################
    ### SNR calculation (as in Meshkat et al. 2014)
    snr=(np.sum(signal_aperture) - (np.mean(bckg_values)) * len(signal_aperture))/\
        (np.std(bckg_values) * np.sqrt(len(signal_aperture)) )

    ##################################################################################

    ### t-test value calculation:
    # Define the sample composed by the means inside the background apertures:
    bckg_apertures_means=[]
    bckg_apertures_fluxes=[]

    for index_mean in range(len(bckg_apertures)):
        bckg_apertures_means.append(np.sum(bckg_apertures[index_mean]) / area)
        bckg_apertures_fluxes.append(np.sum(bckg_apertures[index_mean]))

    bckg_apertures_means=np.array(bckg_apertures_means)
    bckg_apertures_fluxes=np.array(bckg_apertures_fluxes)

    #Calculate t-test value (according to Mawet et al. 2014):
    # In this way, the value that I am assigning to each resolution element is the MEAN of the pixel values:
    t_test=np.abs(((np.sum(signal_aperture)/area) - np.sum(bckg_apertures_means)/len(bckg_apertures_means))/\
           (np.std(bckg_apertures_means) * np.sqrt(1. + 1./len(bckg_apertures_means))))

    # #In this way, the value that I am assigning to each resolution element is the FLUX of the pixel values:
    # t_test=np.abs(((np.sum(signal_aperture)) - np.sum(bckg_apertures_fluxes)/len(bckg_apertures_fluxes))/\
    #        (np.std(bckg_apertures_fluxes) * np.sqrt(1. + 1./len(bckg_apertures_fluxes))))


    #Calculate the t-test value and fpf for all of the other background aperture (but always ignoring the signal one):
    fpf_bckgs=np.zeros(len(bckg_apertures_means))
    for i_t_test in range(len(bckg_apertures_means)):
        bckg_apertures_means_i=np.delete(bckg_apertures_means,i_t_test)
        t_test_i=np.abs((np.sum(bckg_apertures[i_t_test])/area - np.sum(bckg_apertures_means_i)/len(bckg_apertures_means_i))/\
                 (np.std(bckg_apertures_means_i) * np.sqrt(1. + 1./len(bckg_apertures_means_i))))
        fpf_i= 1. - t.cdf(t_test_i,len(bckg_apertures_means_i)-1)
        fpf_bckgs[i_t_test]=fpf_i

    #Given the t-test value, calculate the false alarm probability:
    # nb: define in this way, it is a ONE SIDE TEST!!
    fpf= 1. - t.cdf(t_test,len(bckg_apertures_means)-1)
    # print 'FPF : '+str(fpf)
    ##################################################################################

    #Plot the image together with the apertures, if requested:
    if plot ==True:
        # these are matplotlib.patch.Patch properties:
        props = dict(boxstyle='square', facecolor='white')

        #Let's create all the circles:
        #For the planet aperture:
        signal_aperture=plt.Circle((planet_pos[0],planet_pos[1]),radius,color='Crimson',fill=False,linewidth=1)

        fig = plt.gcf()
        ax=fig.add_subplot(111)
        plt.title(name,size=22)
        plt.imshow(data,origin='lower',alpha=0.5)
        fig.gca().add_artist(signal_aperture)

        plt.hold(True)
        if no_planet_nghbr==False:
            for i_plot in range(n_bckg_aps-1):# the minus 1 is to exclude the planet aperture
                background_aperture=plt.Circle((bckg_aps_cntr[i_plot][0],bckg_aps_cntr[i_plot][1]),radius,color='b',fill=False,linewidth=1)
                fig.gca().add_artist(background_aperture)

        if no_planet_nghbr==True:
            for i_plot in range(n_bckg_aps):
                if i_plot != 0 and i_plot != n_bckg_aps-1 and i_plot != n_bckg_aps-2:
                    background_aperture=plt.Circle((bckg_aps_cntr[i_plot][0],bckg_aps_cntr[i_plot][1]),radius,color='b',fill=False,linewidth=1)
                    fig.gca().add_artist(background_aperture)


        plt.text(0.55,0.8,'FPF = '+str('%s' % float('%.2g' % fpf))+'\npos = ['+str('%s' % float('%.3g' % planet_pos[0]))+' , '+str('%s' % float('%.3g' % planet_pos[1]))+']'
                 ,color='black',size=18,bbox=props,transform=ax.transAxes)

        plt.xlim(0,size)
        plt.ylim(0,size)
        plt.colorbar()
        if save==True:
            plt.savefig(str(save_dir)+str(name)+'%s.pdf'%j,clobber=1)
        plt.show()

        #now, let's plot the gaussian fit:
        if method=='fit':
            fig, ax = plt.subplots(1, 1)
            plt.title(name,size=22)
            ax.hold(True)
            ax.imshow(data,origin='lower',alpha=0.5)
            ax.contour(x, y, data_fitted.reshape(size, size), 5, colors='k')
            plt.text(0.55,0.85,'pos = ['+str('%s' % float('%.3g' % planet_pos[0]))+' , '+
                     str('%s' % float('%.3g' % planet_pos[1]))+']'
                     ,color='black',size=18,bbox=props,transform=ax.transAxes)
            plt.xlim(0,size)
            plt.ylim(0,size)
            if save==True:
                plt.savefig(str(save_dir)+'fit/'+str(name)+'_FIT.pdf')
            plt.show()

    # if method=='fit':
    #     print 'Fit : '+str(popt)


    #Save the result as an ASCII table:
    names=['FPF','t_test','SNR','Planet_pos_x','Planet_pos_y','Method']
    results=Table([[fpf],[t_test],[snr],[planet_pos[0]],[planet_pos[1]],[method]],names=names)
    results_name=save_dir+str(name)+'.txt'

    #Print the results:
    results.pprint(max_lines=-1,max_width=-1,align='^')

    #if requested, save the results
    if save==True:
        results.write(results_name,format='ascii.basic',delimiter='\t')
        print 'The result has been saved in '+str(results_name)+'\n'

    #return the final values:
    if method!='fit':
        return (fpf,t_test,snr,planet_pos,bckg_aps_cntr,fpf_bckgs)
    if method=='fit':
        return (fpf,t_test,snr,planet_pos,bckg_aps_cntr,fpf_bckgs,popt,pcov)
Exemplo n.º 14
0
def time_circular_small_exact():
    circular_overlap_grid(-4., 4., -4., 4., 10, 10, 3.,
                          use_exact=1, subpixels=1)
Exemplo n.º 15
0
def time_circular_big_subpixel_5():
    circular_overlap_grid(-4., 4., -4., 4., 100, 100, 3.,
                          use_exact=1, subpixels=5)