Smoothed Line Chart

<h2>Customizable line tension</h2> Line series has two very easy settings that can control how line smoothing algorithm works: <code>tensionX</code> and <code>tensionY</code>. This allows tailoring smoothed line to suit your needs and data. [amcharts2_button href="https://www.amcharts.com/docs/v4/concepts/axes/axis-ranges/"]More about smoothed lines[/amcharts2_button] <h2>Axis ranges</h2> Axis ranges is another powerful feature of amCharts 4. Besides other uses, it allows defining a range on any axis. Any visual property of the series, that falls within this specific range, will be overridden with specific values. [amcharts2_button href="https://www.amcharts.com/docs/v4/concepts/axes/axis-ranges/"]More about axis ranges[/amcharts2_button]

HTML

<script src="https://www.amcharts.com/lib/4/core.js"></script>
<script src="https://www.amcharts.com/lib/4/charts.js"></script>
<script src="https://www.amcharts.com/lib/4/themes/animated.js"></script>
<div id="chartdiv"></div>

CSS

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
}

#chartdiv {
  width: 100%;
  height: 500px;
}

JavaScript

/**
 * ---------------------------------------
 * This demo was created using amCharts 4.
 * 
 * For more information visit:
 * https://www.amcharts.com/
 * 
 * Documentation is available at:
 * https://www.amcharts.com/docs/v4/
 * ---------------------------------------
 */

// Themes begin
am4core.useTheme(am4themes_animated);
// Themes end

// Create chart instance
var chart = am4core.create("chartdiv", am4charts.XYChart);
chart.paddingRight = 20;

// Add data
chart.data = [{
  "year": "1950",
  "value": 31
}, {
  "year": "1951",
  "value": 31
}, {
  "year": "1952",
  "value": 29
}, {
  "year": "1953",
  "value": 29
}, {
  "year": "1954",
  "value": 31
}, {
  "year": "1955",
  "value": 30
}, {
  "year": "1956",
  "value": 29
}, {
  "year": "1957",
  "value": 29
}, {
  "year": "1958",
  "value": 33
}, {
  "year": "1959",
  "value": 33
}, {
  "year": "1960",
  "value": 33
}, {
  "year": "1961",
  "value": 29
}, {
  "year": "1962",
  "value": 29
}, {
  "year": "1963",
  "value": 29
}, {
  "year": "1964",
  "value": 29
}, {
  "year": "1965",
  "value": 29
}, {
  "year": "1966",
  "value": 29
}, {
  "year": "1967",
  "value": 29
}, {
  "year": "1968",
  "value": 29
}, {
  "year": "1969",
  "value": 29
}];

// Create axes
var categoryAxis = chart.xAxes.push(new am4charts.CategoryAxis());
categoryAxis.dataFields.category = "year";
categoryAxis.renderer.minGridDistance = 50;
categoryAxis.renderer.grid.template.location = 0.5;
categoryAxis.startLocation = 0.5;
categoryAxis.endLocation = 0.5;

// Create value axis
var valueAxis = chart.yAxes.push(new am4charts.ValueAxis());
valueAxis.baseValue = 0;

// Create series
var series = chart.series.push(new am4charts.LineSeries());
series.dataFields.valueY = "value";
series.dataFields.categoryX = "year";
series.strokeWidth = 2;
series.tensionX = 0.77;