Chart Axis Display Units and Logarithmic Scale

Fix #3833. Among the options for chart axes in Excel are the ability to show labels as multiples of specific powers of 10, with or without an explanatory label. The Excel spec seems to indicate that that you can customize the multiples to other values, but I don't see how to do that in Excel, so that can be a project for another day if someone figures out how. The label title can also be styled; that is not part of this PR, but I will look into it in future. For now, this PR supports the use of multiples with or without labels.

The axes can also be displayed on a logarithmic scale (any base between 2 and 1000). This PR supports that.

samples/Chart/33_Chart_create_line_dateaxis.php

@@ -335,7 +335,7 @@ $helper->renderChart($chart, __FILE__);
 $spreadsheet->setActiveSheetIndex(1);
 
 // Save Excel 2007 file
-$helper->write($spreadsheet, __FILE__, ['Xlsx'], true);
+$helper->write($spreadsheet, __FILE__, ['Xlsx'], true, resetActiveSheet: false);
 $spreadsheet->disconnectWorksheets();
 
 function dateRange(int $nrows, Spreadsheet $wrkbk): array

samples/Chart/33_Chart_create_scatter5_trendlines.php

@@ -270,4 +270,4 @@ $helper->renderChart($chart, __FILE__);
 $spreadsheet->setActiveSheetIndex(1);
 
 // Save Excel 2007 file
-$helper->write($spreadsheet, __FILE__, ['Xlsx'], true);
+$helper->write($spreadsheet, __FILE__, ['Xlsx'], true, resetActiveSheet: false);

samples/Chart/33_Chart_create_scatter6_value_xaxis.php

@@ -131,4 +131,4 @@ $helper->renderChart($chart, __FILE__);
 $spreadsheet->setActiveSheetIndex(1);
 
 // Save Excel 2007 file
-$helper->write($spreadsheet, __FILE__, ['Xlsx'], true);
+$helper->write($spreadsheet, __FILE__, ['Xlsx'], true, resetActiveSheet: false);

src/PhpSpreadsheet/Chart/Axis.php

@@ -49,6 +49,8 @@ class Axis extends Properties
 
     private ?AxisText $axisText = null;
 
+    private ?Title $dispUnitsTitle = null;
+
     /**
      * Axis Options.
      *
@@ -70,6 +72,28 @@ class Axis extends Properties
         'majorTimeUnit' => self::TIME_UNIT_YEARS,
         'minorTimeUnit' => self::TIME_UNIT_MONTHS,
         'baseTimeUnit' => self::TIME_UNIT_DAYS,
+        'logBase' => null,
+        'dispUnitsBuiltIn' => null,
+    ];
+    public const DISP_UNITS_HUNDREDS = 'hundreds';
+    public const DISP_UNITS_THOUSANDS = 'thousands';
+    public const DISP_UNITS_TEN_THOUSANDS = 'tenThousands';
+    public const DISP_UNITS_HUNDRED_THOUSANDS = 'hundredThousands';
+    public const DISP_UNITS_MILLIONS = 'millions';
+    public const DISP_UNITS_TEN_MILLIONS = 'tenMillions';
+    public const DISP_UNITS_HUNDRED_MILLIONS = 'hundredMillions';
+    public const DISP_UNITS_BILLIONS = 'billions';
+    public const DISP_UNITS_TRILLIONS = 'trillions';
+    public const DISP_UNITS_BUILTIN_INT = [
+        100 => self::DISP_UNITS_HUNDREDS,
+        1000 => self::DISP_UNITS_THOUSANDS,
+        10000 => self::DISP_UNITS_TEN_THOUSANDS,
+        100000 => self::DISP_UNITS_HUNDRED_THOUSANDS,
+        1000000 => self::DISP_UNITS_MILLIONS,
+        10000000 => self::DISP_UNITS_TEN_MILLIONS,
+        100000000 => self::DISP_UNITS_HUNDRED_MILLIONS,
+        1000000000 => self::DISP_UNITS_BILLIONS,
+        1000000000000 => self::DISP_UNITS_TRILLIONS,
     ];
 
     /**
@@ -149,7 +173,9 @@ class Axis extends Properties
         ?string $hidden = null,
         ?string $baseTimeUnit = null,
         ?string $majorTimeUnit = null,
-        ?string $minorTimeUnit = null
+        ?string $minorTimeUnit = null,
+        null|float|int|string $logBase = null,
+        ?string $dispUnitsBuiltIn = null
     ): void {
         $this->axisOptions['axis_labels'] = $axisLabels;
         $this->setAxisOption('horizontal_crosses_value', $horizontalCrossesValue);
@@ -166,6 +192,8 @@ class Axis extends Properties
         $this->setAxisOption('baseTimeUnit', $baseTimeUnit);
         $this->setAxisOption('majorTimeUnit', $majorTimeUnit);
         $this->setAxisOption('minorTimeUnit', $minorTimeUnit);
+        $this->setAxisOption('logBase', $logBase);
+        $this->setAxisOption('dispUnitsBuiltIn', $dispUnitsBuiltIn);
     }
 
     /**
@@ -317,6 +345,18 @@ class Axis extends Properties
         return $this->noFill;
     }
 
+    public function setDispUnitsTitle(?Title $dispUnitsTitle): self
+    {
+        $this->dispUnitsTitle = $dispUnitsTitle;
+
+        return $this;
+    }
+
+    public function getDispUnitsTitle(): ?Title
+    {
+        return $this->dispUnitsTitle;
+    }
+
     /**
      * Implement PHP __clone to create a deep clone, not just a shallow copy.
      */
@@ -326,6 +366,7 @@ class Axis extends Properties
         $this->majorGridlines = ($this->majorGridlines === null) ? null : clone $this->majorGridlines;
         $this->majorGridlines = ($this->minorGridlines === null) ? null : clone $this->minorGridlines;
         $this->axisText = ($this->axisText === null) ? null : clone $this->axisText;
+        $this->dispUnitsTitle = ($this->dispUnitsTitle === null) ? null : clone $this->dispUnitsTitle;
         $this->fillColor = clone $this->fillColor;
     }
 }

src/PhpSpreadsheet/Chart/Title.php

@@ -16,7 +16,7 @@ class Title
     /**
      * Title Caption.
      *
-     * @var array|RichText|string
+     * @var null|array|RichText|string may be null
      */
     private $caption = '';
 
@@ -39,7 +39,7 @@ class Title
     /**
      * Create a new Title.
      *
-     * @param array|RichText|string $caption
+     * @param null|array|RichText|string $caption may be null
      * @param bool $overlay
      */
     public function __construct($caption = '', ?Layout $layout = null, $overlay = false)
@@ -52,7 +52,7 @@ class Title
     /**
      * Get caption.
      *
-     * @return array|RichText|string
+     * @return null|array|RichText|string may be null
      */
     public function getCaption()
     {
@@ -68,6 +68,9 @@ class Title
             }
         }
         $caption = $this->caption;
+        if ($caption === null) {
+            return '';
+        }
         if (is_string($caption)) {
             return $caption;
         }
@@ -91,7 +94,7 @@ class Title
     /**
      * Set caption.
      *
-     * @param array|RichText|string $caption
+     * @param null|array|RichText|string $caption may be null
      *
      * @return $this
      */

src/PhpSpreadsheet/Helper/Sample.php

@@ -111,13 +111,14 @@ class Sample
     /**
      * Write documents.
      *
-     * @param string $filename
      * @param string[] $writers
      */
-    public function write(Spreadsheet $spreadsheet, $filename, array $writers = ['Xlsx', 'Xls'], bool $withCharts = false, ?callable $writerCallback = null): void
+    public function write(Spreadsheet $spreadsheet, string $filename, array $writers = ['Xlsx', 'Xls'], bool $withCharts = false, ?callable $writerCallback = null, bool $resetActiveSheet = true): void
     {
         // Set active sheet index to the first sheet, so Excel opens this as the first sheet
-        $spreadsheet->setActiveSheetIndex(0);
+        if ($resetActiveSheet) {
+            $spreadsheet->setActiveSheetIndex(0);
+        }
 
         // Write documents
         foreach ($writers as $writerType) {

src/PhpSpreadsheet/Reader/Xlsx/Chart.php

@@ -494,7 +494,7 @@ class Chart
 
     private function chartTitle(SimpleXMLElement $titleDetails): Title
     {
-        $caption = [];
+        $caption = null;
         $titleLayout = null;
         $titleOverlay = false;
         $titleFormula = null;
@@ -503,6 +503,7 @@ class Chart
             $chartDetail = Xlsx::testSimpleXml($chartDetail);
             switch ($titleDetailKey) {
                 case 'tx':
+                    $caption = [];
                     if (isset($chartDetail->rich)) {
                         $titleDetails = $chartDetail->rich->children($this->aNamespace);
                         foreach ($titleDetails as $titleKey => $titleDetail) {
@@ -1518,6 +1519,13 @@ class Chart
         if (isset($chartDetail->crossBetween)) {
             $whichAxis->setCrossBetween((string) self::getAttributeString($chartDetail->crossBetween, 'val'));
         }
+        if (isset($chartDetail->dispUnits, $chartDetail->dispUnits->builtInUnit)) {
+            $whichAxis->setAxisOption('dispUnitsBuiltIn', (string) self::getAttributeString($chartDetail->dispUnits->builtInUnit, 'val'));
+            if (isset($chartDetail->dispUnits->dispUnitsLbl)) {
+                $whichAxis->setDispUnitsTitle(new Title());
+                // TODO parse title elements
+            }
+        }
         if (isset($chartDetail->majorTickMark)) {
             $whichAxis->setAxisOption('major_tick_mark', (string) self::getAttributeString($chartDetail->majorTickMark, 'val'));
         }
@@ -1533,6 +1541,9 @@ class Chart
         if (isset($chartDetail->crossesAt)) {
             $whichAxis->setAxisOption('horizontal_crosses_value', (string) self::getAttributeString($chartDetail->crossesAt, 'val'));
         }
+        if (isset($chartDetail->scaling->logBase)) {
+            $whichAxis->setAxisOption('logBase', (string) self::getAttributeString($chartDetail->scaling->logBase, 'val'));
+        }
         if (isset($chartDetail->scaling->orientation)) {
             $whichAxis->setAxisOption('orientation', (string) self::getAttributeString($chartDetail->scaling->orientation, 'val'));
         }

src/PhpSpreadsheet/Writer/Xlsx/Chart.php

@@ -158,38 +158,40 @@ class Chart extends WriterPart
         }
 
         $objWriter->startElement('c:title');
-        $objWriter->startElement('c:tx');
-        $objWriter->startElement('c:rich');
-
-        $objWriter->startElement('a:bodyPr');
-        $objWriter->endElement();
-
-        $objWriter->startElement('a:lstStyle');
-        $objWriter->endElement();
-
-        $objWriter->startElement('a:p');
-        $objWriter->startElement('a:pPr');
-        $objWriter->startElement('a:defRPr');
-        $objWriter->endElement();
-        $objWriter->endElement();
-
         $caption = $title->getCaption();
-        if (is_array($caption)) {
-            $caption = $caption[0] ?? '';
-        }
-        $this->getParentWriter()->getWriterPartstringtable()->writeRichTextForCharts($objWriter, $caption, 'a');
+        if ($caption !== null) {
+            $objWriter->startElement('c:tx');
+            $objWriter->startElement('c:rich');
 
-        $objWriter->endElement();
-        $objWriter->endElement();
-        $objWriter->endElement();
+            $objWriter->startElement('a:bodyPr');
+            $objWriter->endElement(); // a:bodyPr
+
+            $objWriter->startElement('a:lstStyle');
+            $objWriter->endElement(); // a:lstStyle
+
+            $objWriter->startElement('a:p');
+            $objWriter->startElement('a:pPr');
+            $objWriter->startElement('a:defRPr');
+            $objWriter->endElement(); // a:defRPr
+            $objWriter->endElement(); // a:pPr
+
+            if (is_array($caption)) {
+                $caption = $caption[0] ?? '';
+            }
+            $this->getParentWriter()->getWriterPartstringtable()->writeRichTextForCharts($objWriter, $caption, 'a');
+
+            $objWriter->endElement(); // a:p
+            $objWriter->endElement(); // c:rich
+            $objWriter->endElement(); // c:tx
+        }
 
         $this->writeLayout($objWriter, $title->getLayout());
 
         $objWriter->startElement('c:overlay');
         $objWriter->writeAttribute('val', ($title->getOverlay()) ? '1' : '0');
-        $objWriter->endElement();
+        $objWriter->endElement(); // c:overlay
 
-        $objWriter->endElement();
+        $objWriter->endElement(); // c:title
     }
 
     /**
@@ -587,6 +589,14 @@ class Chart extends WriterPart
         }
 
         $objWriter->startElement('c:scaling');
+        if (is_numeric($yAxis->getAxisOptionsProperty('logBase'))) {
+            $logBase = $yAxis->getAxisOptionsProperty('logBase') + 0;
+            if ($logBase >= 2 && $logBase <= 1000) {
+                $objWriter->startElement('c:logBase');
+                $objWriter->writeAttribute('val', (string) $logBase);
+                $objWriter->endElement();
+            }
+        }
         if ($yAxis->getAxisOptionsProperty('maximum') !== null) {
             $objWriter->startElement('c:max');
             $objWriter->writeAttribute('val', $yAxis->getAxisOptionsProperty('maximum'));
@@ -632,35 +642,37 @@ class Chart extends WriterPart
 
         if ($xAxisLabel !== null) {
             $objWriter->startElement('c:title');
-            $objWriter->startElement('c:tx');
-            $objWriter->startElement('c:rich');
-
-            $objWriter->startElement('a:bodyPr');
-            $objWriter->endElement();
-
-            $objWriter->startElement('a:lstStyle');
-            $objWriter->endElement();
-
-            $objWriter->startElement('a:p');
-
             $caption = $xAxisLabel->getCaption();
-            if (is_array($caption)) {
-                $caption = $caption[0];
-            }
-            $this->getParentWriter()->getWriterPartstringtable()->writeRichTextForCharts($objWriter, $caption, 'a');
+            if ($caption !== null) {
+                $objWriter->startElement('c:tx');
+                $objWriter->startElement('c:rich');
 
-            $objWriter->endElement();
-            $objWriter->endElement();
-            $objWriter->endElement();
+                $objWriter->startElement('a:bodyPr');
+                $objWriter->endElement(); // a:bodyPr
+
+                $objWriter->startElement('a:lstStyle');
+                $objWriter->endElement(); // a::lstStyle
+
+                $objWriter->startElement('a:p');
+
+                if (is_array($caption)) {
+                    $caption = $caption[0];
+                }
+                $this->getParentWriter()->getWriterPartstringtable()->writeRichTextForCharts($objWriter, $caption, 'a');
+
+                $objWriter->endElement(); // a:p
+                $objWriter->endElement(); // c:rich
+                $objWriter->endElement(); // c:tx
+            }
 
             $layout = $xAxisLabel->getLayout();
             $this->writeLayout($objWriter, $layout);
 
             $objWriter->startElement('c:overlay');
             $objWriter->writeAttribute('val', '0');
-            $objWriter->endElement();
+            $objWriter->endElement(); // c:overlay
 
-            $objWriter->endElement();
+            $objWriter->endElement(); // c:title
         }
 
         $objWriter->startElement('c:numFmt');
@@ -796,6 +808,14 @@ class Chart extends WriterPart
         }
 
         $objWriter->startElement('c:scaling');
+        if (is_numeric($xAxis->getAxisOptionsProperty('logBase'))) {
+            $logBase = $xAxis->getAxisOptionsProperty('logBase') + 0;
+            if ($logBase >= 2 && $logBase <= 1000) {
+                $objWriter->startElement('c:logBase');
+                $objWriter->writeAttribute('val', (string) $logBase);
+                $objWriter->endElement();
+            }
+        }
 
         if ($xAxis->getAxisOptionsProperty('maximum') !== null) {
             $objWriter->startElement('c:max');
@@ -845,26 +865,28 @@ class Chart extends WriterPart
 
         if ($yAxisLabel !== null) {
             $objWriter->startElement('c:title');
-            $objWriter->startElement('c:tx');
-            $objWriter->startElement('c:rich');
-
-            $objWriter->startElement('a:bodyPr');
-            $objWriter->endElement();
-
-            $objWriter->startElement('a:lstStyle');
-            $objWriter->endElement();
-
-            $objWriter->startElement('a:p');
-
             $caption = $yAxisLabel->getCaption();
-            if (is_array($caption)) {
-                $caption = $caption[0];
-            }
-            $this->getParentWriter()->getWriterPartstringtable()->writeRichTextForCharts($objWriter, $caption, 'a');
+            if ($caption !== null) {
+                $objWriter->startElement('c:tx');
+                $objWriter->startElement('c:rich');
 
-            $objWriter->endElement();
-            $objWriter->endElement();
-            $objWriter->endElement();
+                $objWriter->startElement('a:bodyPr');
+                $objWriter->endElement(); // a:bodyPr
+
+                $objWriter->startElement('a:lstStyle');
+                $objWriter->endElement(); // a:lstStyle
+
+                $objWriter->startElement('a:p');
+
+                if (is_array($caption)) {
+                    $caption = $caption[0];
+                }
+                $this->getParentWriter()->getWriterPartstringtable()->writeRichTextForCharts($objWriter, $caption, 'a');
+
+                $objWriter->endElement(); // a:p
+                $objWriter->endElement(); // c:rich
+                $objWriter->endElement(); // c:tx
+            }
 
             if ($groupType !== DataSeries::TYPE_BUBBLECHART) {
                 $layout = $yAxisLabel->getLayout();
@@ -873,9 +895,9 @@ class Chart extends WriterPart
 
             $objWriter->startElement('c:overlay');
             $objWriter->writeAttribute('val', '0');
-            $objWriter->endElement();
+            $objWriter->endElement(); // c:overlay
 
-            $objWriter->endElement();
+            $objWriter->endElement(); // c:title
         }
 
         $objWriter->startElement('c:numFmt');
@@ -950,6 +972,22 @@ class Chart extends WriterPart
                 $objWriter->endElement();
             }
 
+            if ($xAxis->getAxisType() === Axis::AXIS_TYPE_VALUE) {
+                $dispUnits = $xAxis->getAxisOptionsProperty('dispUnitsBuiltIn');
+                $dispUnits = is_numeric($dispUnits) ? (Axis::DISP_UNITS_BUILTIN_INT[(int) $dispUnits] ?? '') : $dispUnits;
+                if (in_array($dispUnits, Axis::DISP_UNITS_BUILTIN_INT, true)) {
+                    $objWriter->startElement('c:dispUnits');
+                    $objWriter->startElement('c:builtInUnit');
+                    $objWriter->writeAttribute('val', $dispUnits);
+                    $objWriter->endElement(); // c:builtInUnit
+                    if ($xAxis->getDispUnitsTitle() !== null) {
+                        // TODO output title elements
+                        $objWriter->writeElement('c:dispUnitsLbl');
+                    }
+                    $objWriter->endElement(); // c:dispUnits
+                }
+            }
+
             if ($xAxis->getAxisOptionsProperty('major_unit') !== null) {
                 $objWriter->startElement('c:majorUnit');
                 $objWriter->writeAttribute('val', $xAxis->getAxisOptionsProperty('major_unit'));

tests/PhpSpreadsheetTests/Chart/Issue3833Test.php

@@ -0,0 +1,142 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpOffice\PhpSpreadsheetTests\Chart;
+
+use PhpOffice\PhpSpreadsheet\Reader\Xlsx as XlsxReader;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx as XlsxWriter;
+use PhpOffice\PhpSpreadsheetTests\Functional\AbstractFunctional;
+
+class Issue3833Test extends AbstractFunctional
+{
+    // based on 33_Char_create_scatter2
+    public function readCharts(XlsxReader $reader): void
+    {
+        $reader->setIncludeCharts(true);
+    }
+
+    public function writeCharts(XlsxWriter $writer): void
+    {
+        $writer->setIncludeCharts(true);
+    }
+
+    public function testDisplayUnits1(): void
+    {
+        $reader = new XlsxReader();
+        $reader->setIncludeCharts(true);
+        $spreadsheet = $reader->load('tests/data/Reader/XLSX/issue.3833.units.xlsx');
+
+        /** @var callable */
+        $callableReader = [$this, 'readCharts'];
+        /** @var callable */
+        $callableWriter = [$this, 'writeCharts'];
+        $reloadedSpreadsheet = $this->writeAndReload($spreadsheet, 'Xlsx', $callableReader, $callableWriter);
+        $spreadsheet->disconnectWorksheets();
+
+        $sheet = $reloadedSpreadsheet->getSheetByNameOrThrow('charts');
+        $charts2 = $sheet->getChartCollection();
+        self::assertCount(1, $charts2);
+        $chart2 = $charts2[0];
+        self::assertNotNull($chart2);
+        $yAxis = $chart2->getChartAxisY();
+        $dispUnits = $yAxis->getAxisOptionsProperty('dispUnitsBuiltIn');
+        self::assertSame('tenThousands', $dispUnits);
+        $logBase = $yAxis->getAxisOptionsProperty('logBase');
+        self::assertNull($logBase);
+
+        $reloadedSpreadsheet->disconnectWorksheets();
+    }
+
+    public function testDisplayUnits2(): void
+    {
+        $reader = new XlsxReader();
+        $reader->setIncludeCharts(true);
+        $spreadsheet = $reader->load('tests/data/Reader/XLSX/issue.3833.units.xlsx');
+        $sheet1 = $spreadsheet->getSheetByNameOrThrow('charts');
+        $charts1 = $sheet1->getChartCollection();
+        self::assertCount(1, $charts1);
+        $chart1 = $charts1[0];
+        self::assertNotNull($chart1);
+        $yAxis1 = $chart1->getChartAxisY();
+        $yAxis1->setAxisOption('dispUnitsBuiltIn', 1000);
+
+        /** @var callable */
+        $callableReader = [$this, 'readCharts'];
+        /** @var callable */
+        $callableWriter = [$this, 'writeCharts'];
+        $reloadedSpreadsheet = $this->writeAndReload($spreadsheet, 'Xlsx', $callableReader, $callableWriter);
+        $spreadsheet->disconnectWorksheets();
+
+        $sheet = $reloadedSpreadsheet->getSheetByNameOrThrow('charts');
+        $charts2 = $sheet->getChartCollection();
+        self::assertCount(1, $charts2);
+        $chart2 = $charts2[0];
+        self::assertNotNull($chart2);
+        $yAxis = $chart2->getChartAxisY();
+        $dispUnits = $yAxis->getAxisOptionsProperty('dispUnitsBuiltIn');
+        self::assertSame('thousands', $dispUnits);
+        $logBase = $yAxis->getAxisOptionsProperty('logBase');
+        self::assertNull($logBase);
+
+        $reloadedSpreadsheet->disconnectWorksheets();
+    }
+
+    public function testDisplayUnits3(): void
+    {
+        $reader = new XlsxReader();
+        $reader->setIncludeCharts(true);
+        $spreadsheet = $reader->load('tests/data/Reader/XLSX/issue.3833.units.xlsx');
+        $sheet1 = $spreadsheet->getSheetByNameOrThrow('charts');
+        $charts1 = $sheet1->getChartCollection();
+        self::assertCount(1, $charts1);
+        $chart1 = $charts1[0];
+        self::assertNotNull($chart1);
+        $yAxis1 = $chart1->getChartAxisY();
+        $yAxis1->setDispUnitsTitle(null);
+
+        /** @var callable */
+        $callableReader = [$this, 'readCharts'];
+        /** @var callable */
+        $callableWriter = [$this, 'writeCharts'];
+        $reloadedSpreadsheet = $this->writeAndReload($spreadsheet, 'Xlsx', $callableReader, $callableWriter);
+        $spreadsheet->disconnectWorksheets();
+
+        $sheet = $reloadedSpreadsheet->getSheetByNameOrThrow('charts');
+        $charts2 = $sheet->getChartCollection();
+        self::assertCount(1, $charts2);
+        $chart2 = $charts2[0];
+        self::assertNotNull($chart2);
+        $yAxis = $chart2->getChartAxisY();
+        self::assertNull($yAxis->getDispUnitsTitle());
+
+        $reloadedSpreadsheet->disconnectWorksheets();
+    }
+
+    public function testLogBase(): void
+    {
+        $reader = new XlsxReader();
+        $reader->setIncludeCharts(true);
+        $spreadsheet = $reader->load('tests/data/Reader/XLSX/issue.3833.logarithm.xlsx');
+
+        /** @var callable */
+        $callableReader = [$this, 'readCharts'];
+        /** @var callable */
+        $callableWriter = [$this, 'writeCharts'];
+        $reloadedSpreadsheet = $this->writeAndReload($spreadsheet, 'Xlsx', $callableReader, $callableWriter);
+        $spreadsheet->disconnectWorksheets();
+
+        $sheet = $reloadedSpreadsheet->getSheetByNameOrThrow('charts');
+        $charts2 = $sheet->getChartCollection();
+        self::assertCount(1, $charts2);
+        $chart2 = $charts2[0];
+        self::assertNotNull($chart2);
+        $yAxis = $chart2->getChartAxisY();
+        $logBase = $yAxis->getAxisOptionsProperty('logBase');
+        self::assertSame('10', $logBase);
+        $dispUnits = $yAxis->getAxisOptionsProperty('dispUnitsBuiltIn');
+        self::assertNull($dispUnits);
+
+        $reloadedSpreadsheet->disconnectWorksheets();
+    }
+}