Added ZigzagPersistence::is_alive() + consistency zigzag outputs betti 1 at each stage
From: Dmitriy Morozov <morozov@cs.duke.edu>
Date: Fri, 22 Feb 2008 18:39:31 -0500
State: new
Subject: Incorrect sign_at() in UPolynomial<double>
Message-Id: <cd79223a108d3900-0-artemis@metatron>
UPolynomial<double>::sign_at() reports -1 as the sign of -2*x + 4 at x = 2.
Should be 0.