binarylens.py 文件源码

def _get_magnification_w_times(self, source_x, source_y, radius,
                                   magnification_center=None):
        """Evaluates Gould (2008) eq. 8"""
        shift = radius / sqrt(2.)
        dx = [1., -1., -1., 1.]
        dy = [1., 1., -1., -1.]
        out = []
        for (i, dxval) in enumerate(dx):
            x = source_x + dxval * shift
            y = source_y + dy[i] * shift
            out.append(self.point_source_magnification(
                                              source_x=x, source_y=y))
        if magnification_center is None:
            magnification_center = self.point_source_magnification(
                                    source_x=source_x, source_y=source_y)
        return 0.25 * fsum(out) - magnification_center