When you add a chart to a report, it typically displays above the report data, as in the example below:
However, this default display may not suit your needs. In Pega 7, it is easy to have the chart display by itself.
To display just the chart, open the Report Definition record for the report in question. On the Report Viewer tab, check the Hide summary data display checkbox:
Save the record and run the report. Now the chart appears by itself:
To export the chart as a PDF, select Print from the toolbar, then choose the Print to PDF option. The chart appears in the resulting PDF without its supporting data, as in the image below: