X Axis Vs. Category Axis with JavaScript via C++
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Possible Usage Scenarios
There are different types of X axes. While the Y axis is a Value type axis, the X axis can be a Category type axis or a Value type axis. Using a Value axis, the data is treated as continuously varying numerical data, and the marker is placed at a point along the axis which varies according to its numerical value. Using a Category axis, the data is treated as a sequence of non-numerical text labels, and the marker is placed at a point along the axis according to its position in the sequence. The sample below illustrates the difference between Value and Category Axes. Our sample data is shown in the sample Table file below. The first column contains our X axis data, which can be treated as Categories or as Values. Note that the numbers are not equally spaced, nor do they even appear in numerical order.
Handle X and Category axis like Microsoft Excel
We will display this data on two types of chart, the first chart is XY (Scatter) chart X as Value Axis, the second chart is line chart X as Category Axis.
Sample Code
<!DOCTYPE html>
<html>
<head>
<title>Aspose.Cells Example</title>
</head>
<body>
<h1>Aspose.Cells Example - Charts and X Axis</h1>
<input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
<button id="runExample">Run Example</button>
<a id="downloadLink" style="display: none;">Download Result</a>
<div id="result"></div>
</body>
<script src="aspose.cells.js.min.js"></script>
<script type="text/javascript">
const { Workbook, SaveFormat, ChartType, LegendPositionType, FillType, Utils } = AsposeCells;
AsposeCells.onReady({
license: "/lic/aspose.cells.enc",
fontPath: "/fonts/",
fontList: [
"arial.ttf",
"NotoSansSC-Regular.ttf"
]
}).then(() => {
console.log("Aspose.Cells initialized");
});
document.getElementById('runExample').addEventListener('click', async () => {
const fileInput = document.getElementById('fileInput');
if (!fileInput.files.length) {
document.getElementById('result').innerHTML = '<p style="color: red;">Please select an Excel file.</p>';
return;
}
const file = fileInput.files[0];
const arrayBuffer = await file.arrayBuffer();
// Loads the workbook which contains hidden external links
const workbook = new Workbook(new Uint8Array(arrayBuffer));
// Access the first worksheet.
const worksheet = workbook.worksheets.get(0);
// Put the sample values used in charts
worksheet.cells.get("A2").putValue(1);
worksheet.cells.get("A3").putValue(3);
worksheet.cells.get("A4").putValue(2.5);
worksheet.cells.get("A5").putValue(3.5);
worksheet.cells.get("B1").putValue("Cats");
worksheet.cells.get("C1").putValue("Dogs");
worksheet.cells.get("D1").putValue("Fishes");
worksheet.cells.get("B2").putValue(7);
worksheet.cells.get("B3").putValue(6);
worksheet.cells.get("B4").putValue(5);
worksheet.cells.get("B5").putValue(4);
worksheet.cells.get("C2").putValue(7);
worksheet.cells.get("C3").putValue(5);
worksheet.cells.get("C4").putValue(4);
worksheet.cells.get("C5").putValue(3);
worksheet.cells.get("D2").putValue(8);
worksheet.cells.get("D3").putValue(7);
worksheet.cells.get("D4").putValue(3);
worksheet.cells.get("D5").putValue(2);
// Create Line Chart: X as Category Axis
let pieIdx = worksheet.charts.add(ChartType.LineWithDataMarkers, 6, 15, 20, 21);
// Retrieve the Chart object
let chart = worksheet.charts.get(pieIdx);
// Add Series
chart.nSeries.add("B2:D5", true);
// Set the category data
chart.nSeries.categoryData = "=Sheet1!$A$2:$A$5";
// Set the first series name
chart.nSeries.get(0).name = "Cats";
// Set the second series name
chart.nSeries.get(1).name = "Dogs";
// Set the third series name
chart.nSeries.get(2).name = "Fishes";
// Set the Legend at the bottom of the chart area
chart.legend.position = LegendPositionType.Bottom;
// Fill the PlotArea area with nothing
chart.plotArea.area.fillFormat.fillType = FillType.None;
// Create XY (Scatter) Chart: X as Value Axis
pieIdx = worksheet.charts.add(ChartType.ScatterConnectedByLinesWithDataMarker, 6, 6, 20, 12);
// Retrieve the Chart object
chart = worksheet.charts.get(pieIdx);
// Add Series
chart.nSeries.add("B2:D5", true);
// Set X values for series
chart.nSeries.get(0).xValues = "{1,3,2.5,3.5}";
chart.nSeries.get(1).xValues = "{1,3,2.5,3.5}";
chart.nSeries.get(2).xValues = "{1,3,2.5,3.5}";
// Set the first series name
chart.nSeries.get(0).name = "Cats";
// Set the second series name
chart.nSeries.get(1).name = "Dogs";
// Set the third series name
chart.nSeries.get(2).name = "Fishes";
// Set the Legend at the bottom of the chart area
chart.legend.position = LegendPositionType.Bottom;
// Fill the PlotArea area with nothing
chart.plotArea.area.fillFormat.fillType = FillType.None;
// Saving the modified Excel file
const outputData = workbook.save(SaveFormat.Xlsx);
const blob = new Blob([outputData]);
const downloadLink = document.getElementById('downloadLink');
downloadLink.href = URL.createObjectURL(blob);
downloadLink.download = 'XAxis.xlsx';
downloadLink.style.display = 'block';
downloadLink.textContent = 'Download Excel File';
document.getElementById('result').innerHTML = '<p style="color: green;">Operation completed successfully! Click the download link to get the modified file.</p>';
});
</script>
</html>