us'><div class = 'inlineWrapper'><div class = "S2 lineNode"><span class = "S3"><span class="S0">err = abs(x-r(1));</span></span></div></div><div class = 'inlineWrapper'><div class = "S2 lineNode"><span class = "S3"><span class="S0">semilogy(err,</span><span class="S8">'.-'</span><span class="S0">), axis </span><span class="S8">tight</span></span></div></div><div class = 'inlineWrapper'><div class = "S2 lineNode"><span class = "S3"><span class="S0">xlabel(</span><span class="S8">'iteration'</span><span class