This plugin adds a widget to display download statistics based on the <a href="https://wordpress.org/extend/plugins/wp-downloadcounter/" rel="ugc">Download Counter</a> 
plugin on your site. The sidebar widget will show a highly configurable chart based on the 
<a href="http://code.google.com/apis/chart/" rel="nofollow ugc">Google Chart API</a>. Furthermore it offers a dashboard widget that summarizes your 
downloads, to get information quick at a glance.
The plugin supports following chart types:
<ul>
<li>Bar (horizontal)</li>
<li>Pie </li>
<li>Pie 3D</li>
</ul>
You can include a chart of your downloads on a page or in a post using the downloadcounterchart-shortcode. 
Of course a download chart is includable in your theme. See <a href="https://wordpress.org/extend/plugins/wp-downloadcounter-chart/other_notes/" rel="ugc">extended documentation</a> 
for detailed explanations for that.
<h3>Usage</h3>
There are several ways to include a chart of your downloads on your site.
<h4>Page / Post (Shortcode)</h4>
<pre>[downloadcounterchart chart_type="pie" chart_width="490" chart_height="190" label_color="000000" label_size="11" sqlcondition="" bar_color="0066CC90" bar_height="-1" bg_color="FFFFFF00"]</pre>
Parameters:
<ul>
<li>chart_type – Type of the chart. Valid values: <code>bar_horizontal</code>, <code>pie</code> or <code>pie3d</code>.</li>
<li>chart_width – Width of the chart image in px. May be about the 2.5 times size of the height for a pie chart.</li>
<li>chart_height – Width of the chart image in px.</li>
<li>label_color – Hex color value for labels, optional with additional opacity value (e.g. 50% black = 00000050).</li>
<li>label_size – Font size of the labels.</li>
<li>sqlcondition – Optional SQL where statement, leave blank for all downloads.</li>
<li>bar_height – Bar chart only. You can explicitly set the bar height, but it may result in a chart that does not include 
all data, if the chart height is not big enough. Recommend to set <code>-1</code> for auto-sizing.</li>
<li>bg_color – Background color. Hex color value, optional with additional opacity value (e.g. transparent = FFFFFF00)</li>
</ul>
<h4>Theme</h4>
<pre>downloadcounterchart_img($chart_type, $chart_width, $chart_height, $label_color = '333333', $label_size = '11', $sqlcondition = '', $bar_color='', $bar_height='', $bg_color='')</pre>
Parameters:
see section above
Example:
<pre>if (function_exists('downloadcounterchart_img') && class_exists('DownloadCounterChartApi')){
 downloadcounterchart_img(DLC_CHART_PIE, 490, 190, '000000', '11', '', '0066CC', '-1', 'FFFFFF00');
}</pre>

Download Counter Chart

Visualization of your downloads based on the Download Counter plugin.

Download Counter Chart vs Chartify – WordPress Chart Plugin