PhpOffice\PhpPresentation\Writer\PowerPoint2007\PptCharts::writeSeriesMarker PHP Method

    protected function writeSeriesMarker(XMLWriter $objWriter, Chart\Marker $oMarker)
    {
        if ($oMarker->getSymbol() != Chart\Marker::SYMBOL_NONE) {
            $markerSize = (int) $oMarker->getSize();
            if ($markerSize < 2) {
                $markerSize = 2;
            }
            if ($markerSize > 72) {
                $markerSize = 72;
            }
            // c:marker
            $objWriter->startElement('c:marker');
            // c:marker > c:symbol
            $objWriter->startElement('c:symbol');
            $objWriter->writeAttribute('val', $oMarker->getSymbol());
            $objWriter->endElement();
            /**
             * c:marker > c:size
             * Size in points
             * @link : https://msdn.microsoft.com/en-us/library/hh658135(v=office.12).aspx
             */
            $objWriter->startElement('c:size');
            $objWriter->writeAttribute('val', $markerSize);
            $objWriter->endElement();
            $objWriter->endElement();
        }
    }