def METHOD_NAME(self):
    """test maximum search using random points: maximum is at a pixel edge"""
    a = numpy.arange(100) - 40.5
    b = numpy.arange(100) - 60.5
    ga = numpy.exp(-a * a / 4000)
    gb = numpy.exp(-b * b / 6000)
    gg = numpy.outer(ga, gb)
    b = BilinearImage(gg)
    ok = 0
    for s in range(self.N):
        i, j = numpy.random.randint(100), numpy.random.randint(100)
        k, l = b.local_maxi((i, j))
        if abs(k - 40.5) > 0.5 or abs(l - 60.5) > 0.5:
            logger.warning("Wrong guess maximum (%i,%i) -> (%.1f,%.1f)", i, j, k, l)
        else:
            logger.debug("Good guess maximum (%i,%i) -> (%.1f,%.1f)", i, j, k, l)
            ok += 1
    logger.debug("Success rate: %.1f", 100. * ok / self.N)
    self.assertEqual(ok, self.N, "Maximum is always found")