-<p>A rolling average can always be set using the text box in the lower left-hand corner of the graph.</p>
+<p>A rolling average can be set using the text box in the lower left-hand corner of the graph (the showRoller attribute is what makes this appear).</p>
<h2>Error Bars</h2>
<p>Another significant feature of the dygraphs library is the ability to display error bars around data series. One standard deviation must be specified for each data point. A +/-<i>n</i> sigma band will be drawn around the data series at that point. If a moving average is being displayed, DateGraph will compute the standard deviation of the average at each point. (i.e. <i>σ</i> = sqrt((<i>σ_1</i>^2 + <i>σ_2</i>^2 + ... + <i>σ_n</i>^2)/<i>n</i>))</p>
<h2>Error Bars</h2>
<p>Another significant feature of the dygraphs library is the ability to display error bars around data series. One standard deviation must be specified for each data point. A +/-<i>n</i> sigma band will be drawn around the data series at that point. If a moving average is being displayed, DateGraph will compute the standard deviation of the average at each point. (i.e. <i>σ</i> = sqrt((<i>σ_1</i>^2 + <i>σ_2</i>^2 + ... + <i>σ_n</i>^2)/<i>n</i>))</p>