Optimize Chart Calculations for Presentations in PHP

Overview

Aspose.Slides provides APIs for working with chart calculations and layout data in presentations. This article shows how to retrieve the actual values of chart elements, including the real position and size of elements and the actual values of chart axes. It also explains that these values are populated after chart layout validation.

In addition, the article demonstrates how to get the actual position of parent chart elements and how to hide chart components such as the title, axes, legend, and grid lines. Together, these examples help you inspect chart layout information and control the visibility of chart elements in PowerPoint presentations programmatically.

Calculate Actual Values of Chart Elements

Aspose.Slides for PHP via Java provides a simple API for getting these properties. Methods of the Axis class provide information about actual position of axis chart element (getActualMaxValue, getActualMinValue, getActualMajorUnit, getActualMinorUnit, getActualMajorUnitScale, getActualMinorUnitScale). It is necessary to call method Chart.validateChartLayout previously to fill properties with actual values.

  $pres = new Presentation();
  try {
    $chart = $pres->getSlides()->get_Item(0)->getShapes()->addChart(ChartType::Area, 100, 100, 500, 350);
    $chart->validateChartLayout();
    $maxValue = $chart->getAxes()->getVerticalAxis()->getActualMaxValue();
    $minValue = $chart->getAxes()->getVerticalAxis()->getActualMinValue();
    $majorUnit = $chart->getAxes()->getHorizontalAxis()->getActualMajorUnit();
    $minorUnit = $chart->getAxes()->getHorizontalAxis()->getActualMinorUnit();
  } finally {
    if (!java_is_null($pres)) {
      $pres->dispose();
    }
  }

Calculate Actual Position of Parent Chart Elements

Aspose.Slides for PHP via Java provides a simple API for getting these properties. Methods of the ActualLayout class provide information about actual position of parent chart element (getActualX, getActualY, getActualWidth, getActualHeight). It is necessary to call method Chart.validateChartLayout previously to fill properties with actual values.

  $pres = new Presentation();
  try {
    $chart = $pres->getSlides()->get_Item(0)->getShapes()->addChart(ChartType::ClusteredColumn, 100, 100, 500, 350);
    $chart->validateChartLayout();
    $x = $chart->getPlotArea()->getActualX();
    $y = $chart->getPlotArea()->getActualY();
    $w = $chart->getPlotArea()->getActualWidth();
    $h = $chart->getPlotArea()->getActualHeight();
  } finally {
    if (!java_is_null($pres)) {
      $pres->dispose();
    }
  }

Hide Chart Elements

This topic helps you to understand how to hide information from chart. Using Aspose.Slides for PHP via Java you can hide Title, Vertical Axis, Horizontal Axis and Grid Lines from chart. Below code example shows how to use these properties.

  $pres = new Presentation();
  try {
    $slide = $pres->getSlides()->get_Item(0);
    $chart = $slide->getShapes()->addChart(ChartType::LineWithMarkers, 140, 118, 320, 370);
    # Hiding chart Title
    $chart->setTitle(false);
    # /Hiding Values axis
    $chart->getAxes()->getVerticalAxis()->setVisible(false);
    # Category Axis visibility
    $chart->getAxes()->getHorizontalAxis()->setVisible(false);
    # Hiding Legend
    $chart->setLegend(false);
    # Hiding MajorGridLines
    $chart->getAxes()->getHorizontalAxis()->getMajorGridLinesFormat()->getLine()->getFillFormat()->setFillType(FillType::NoFill);
    for($i = 0; $i < java_values($chart->getChartData()->getSeries()->size()) ; $i++) {
      $chart->getChartData()->getSeries()->removeAt($i);
    }
    $series = $chart->getChartData()->getSeries()->get_Item(0);
    $series->getMarker()->setSymbol(MarkerStyleType::Circle);
    $series->getLabels()->getDefaultDataLabelFormat()->setShowValue(true);
    $series->getLabels()->getDefaultDataLabelFormat()->setPosition(LegendDataLabelPosition->Top);
    $series->getMarker()->setSize(15);
    # Setting series line color
    $series->getFormat()->getLine()->getFillFormat()->setFillType(FillType::Solid);
    $series->getFormat()->getLine()->getFillFormat()->getSolidFillColor()->setColor(java("java.awt.Color")->MAGENTA);
    $series->getFormat()->getLine()->setDashStyle(LineDashStyle->Solid);
    $pres->save("HideInformationFromChart.pptx", SaveFormat::Pptx);
  } finally {
    if (!java_is_null($pres)) {
      $pres->dispose();
    }
  }

FAQ

Do external Excel workbooks work as a data source, and how does that affect recalculation?

Yes. A chart can reference an external workbook: when you connect or refresh the external source, formulas and values are taken from that workbook, and the chart reflects the updates during open/edit operations. The API lets you specify the external workbook path and manage the linked data.

Can I compute and display trendlines without implementing regression myself?

Yes. Trendlines (linear, exponential, and others) are added and updated by Aspose.Slides; their parameters are recalculated from the series data automatically, so you don’t need to implement your own calculations.

If a presentation has multiple charts with external links, can I control which workbook each chart uses for computed values?

Yes. Each chart can point to its own external workbook, or you can create/replace an external workbook per chart independently of the others.