Settings for real-time QCustomPlot
<p>I use Windows 7 x64, Qt 5.6, Visual Studio 2015, QCustomPlot 1.3.2. I need to draw temperature graph from a sensor (real time). I receive temperature value every 500 ms (<code>frequency</code> = 2 Hz). What settings should I apply to <code>QCustomPlot</code> instance in order to have the last values received during <code>time_period</code> = 10 minutes?
Here is a fragment of renewal slot:</p>

<pre><code>double key = QDateTime::currentDateTime().toMSecsSinceEpoch() / 1000.0;
custom_plot_-&gt;graph(0)-&gt;addData(key, value);
custom_plot_-&gt;graph(0)-&gt;removeDataBefore(old_items_count);
custom_plot_-&gt;xAxis-&gt;setRange(key + some_delta, old_items_count, Qt::AlignRight);
</code></pre>

<p>What are the formulas for variables <code>old_items_count = func1(time_period, frequency)</code> and <code>some_delta = func2(time_period, frequency)</code>?
Official demo contains the following values: <code>old_items_count = 8</code>, <code>some_delta = 0.25</code>.</p>