Graphique.js

Table des matières

Chart.js est une bibliothèque JavaScript gratuite permettant de créer des graphiques HTML. C'est l'une des bibliothèques de visualisation les plus simples pour JavaScript, et est livré avec les nombreux types de graphiques intégrés :

Nuage de points
Graphique en ligne
Diagramme à bandes
Diagramme circulaire
Graphique en beignet
Graphique à bulles
Graphique en aires
Carte radar
Graphique mixte

Comment utiliser Chart.js ?

1. Ajoutez un lien vers le CDN (Content Delivery Network) fournisseur :

<script
src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js">
</script>

2. Ajoutez un <canvas> à l'endroit du code HTML où vous souhaitez dessiner le graphique :

<canvas id="myChart" style="width:100%;max-width:700px"></canvas>

L'élément canvas doit avoir un identifiant unique.

Syntaxe typique d'un graphique à barres :

const myChart = new Chart("myChart", {
  type: "bar",
  data: {},
  options: {}
});

Syntaxe typique d'un graphique linéaire :

const myChart = new Chart("myChart", {
  type: "line",
  data: {},
  options: {}
});

Diagramme à barres

Code source

const xValues = ["Italy", "France", "Spain", "USA", "Argentina"];
const yValues = [55, 49, 44, 24, 15];
const barColors = ["red", "green","blue","orange","brown"];

new Chart("myChart", {
  type: "bar",
  data: {
    labels: xValues,
    datasets: [{
      backgroundColor: barColors,
      data: yValues
    }]
  },
  options: {...}
});

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>

<canvas id="myChart" style="width:100%;max-width:600px"></canvas>

<script>
const xValues = ["Italy", "France", "Spain", "USA", "Argentina"];
const yValues = [55, 49, 44, 24, 15];
const barColors = ["red", "green","blue","orange","brown"];

new Chart("myChart", {
  type: "bar",
  data: {
    labels: xValues,
    datasets: [{
      backgroundColor: barColors,
      data: yValues
    }]
  },
  options: {
    legend: {display: false},
    title: {
      display: true,
      text: "World Wine Production 2018"
    }
  }
});
</script>

</body>
</html>

Colorez une seule barre :

const barColors = ["blue"];

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>

<canvas id="myChart" style="width:100%;max-width:600px"></canvas>

<script>
const xValues = ["Italy", "France", "Spain", "USA", "Argentina"];
const yValues = [55, 49, 44, 24, 15];
const barColors = ["blue"];

new Chart("myChart", {
  type: "bar",
  data: {
    labels: xValues,
    datasets: [{
      backgroundColor: barColors,
      data: yValues
    }]
  },
  options: {
    legend: {display: false},
    scales: {
      yAxes: [{
        ticks: {
          beginAtZero: true
        }
      }],
    }
  }
});
</script>

</body>
</html>

Même couleur pour toutes les barres :

const barColors ="red";

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>

<canvas id="myChart" style="width:100%;max-width:600px"></canvas>

<script>
const xValues = ["Italy", "France", "Spain", "USA", "Argentina"];
const yValues = [55, 49, 44, 24, 15];
let barColors = "red";

new Chart("myChart", {
  type: "bar",
  data: {
    labels: xValues,
    datasets: [{
      backgroundColor: barColors,
      data: yValues
    }]
  },
  options: {
    xlegend: {display: false},
    scales: {
      yAxes: [{
        ticks: {
          beginAtZero: true
        }
      }],
    }
  }
});
</script>

</body>
</html>

Nuances de couleurs :

const barColors = [
  "rgba(0,0,255,1.0)",
  "rgba(0,0,255,0.8)",
  "rgba(0,0,255,0.6)",
  "rgba(0,0,255,0.4)",
  "rgba(0,0,255,0.2)",
];

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>

<canvas id="myChart" style="width:100%;max-width:600px"></canvas>

<script>
const xValues = ["Italy", "France", "Spain", "USA", "Argentina"];
const yValues = [55, 49, 44, 24, 15];
const barColors = [
  "rgba(255,0,0,1.0)",
  "rgba(255,0,0,0.8)",
  "rgba(255,0,0,0.6)",
  "rgba(255,0,0,0.4)",
  "rgba(255,0,0,0.2)"
];

new Chart("myChart", {
  type: "bar",
  data: {
    labels: xValues,
    datasets: [{
      backgroundColor: barColors,
      data: yValues
    }]
  },
  options: {
    legend: {display: false},
    scales: {
      yAxes: [{
        ticks: {
          beginAtZero: true
        }
      }],
    }
  }
});
</script>

</body>
</html>

Barres horizontales

Changez simplement le type de "bar" en "horizontalBar":

type: "horizontalBar",

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>

<canvas id="myChart" style="width:100%;max-width:600px"></canvas>

<script>
var xValues = ["Italy", "France", "Spain", "USA", "Argentina"];
var yValues = [55, 49, 44, 24, 15];
var barColors = ["red", "green","blue","orange","brown"];

new Chart("myChart", {
  type: "horizontalBar",
  data: {
  labels: xValues,
  datasets: [{
    backgroundColor: barColors,
    data: yValues
  }]
},
  options: {
    legend: {display: false},
    title: {
      display: true,
      text: "World Wine Production 2018"
    },
    scales: {
      xAxes: [{ticks: {min: 10, max:60}}]
    }
  }
});
</script>

</body>
</html>

Camemberts

Exemple

new Chart("myChart", {
  type: "pie",
  data: {
    labels: xValues,
    datasets: [{
      backgroundColor: barColors,
      data: yValues
    }]
  },
  options: {
    title: {
      display: true,
      text: "World Wide Wine Production"
    }
  }
});

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>

<canvas id="myChart" style="width:100%;max-width:600px"></canvas>

<script>
const xValues = ["Italy", "France", "Spain", "USA", "Argentina"];
const yValues = [55, 49, 44, 24, 15];
const barColors = [
  "#b91d47",
  "#00aba9",
  "#2b5797",
  "#e8c3b9",
  "#1e7145"
];

new Chart("myChart", {
  type: "pie",
  data: {
    labels: xValues,
    datasets: [{
      backgroundColor: barColors,
      data: yValues
    }]
  },
  options: {
    title: {
      display: true,
      text: "World Wide Wine Production 2018"
    }
  }
});
</script>

</body>
</html>

Graphiques en beignet

Changez simplement le type de « tarte » en « beignet » :

type: "doughnut";

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>

<canvas id="myChart" style="width:100%;max-width:600px"></canvas>

<script>
const xValues = ["Italy", "France", "Spain", "USA", "Argentina"];
const yValues = [55, 49, 44, 24, 15];
const barColors = [
  "#b91d47",
  "#00aba9",
  "#2b5797",
  "#e8c3b9",
  "#1e7145"
];

new Chart("myChart", {
  type: "doughnut",
  data: {
    labels: xValues,
    datasets: [{
      backgroundColor: barColors,
      data: yValues
    }]
  },
  options: {
    title: {
      display: true,
      text: "World Wide Wine Production 2018"
    }
  }
});
</script>

</body>
</html>

Nuages de points

Prix des maisons par rapport à la taille

Code source

const xyValues = [
  {x:50, y:7},
  {x:60, y:8},
  {x:70, y:8},
  {x:80, y:9},
  {x:90, y:9},
  {x:100, y:9},
  {x:110, y:10},
  {x:120, y:11},
  {x:130, y:14},
  {x:140, y:14},
  {x:150, y:15}
];

new Chart("myChart", {
  type: "scatter",
  data: {
    datasets: [{
      pointRadius: 4,
      pointBackgroundColor: "rgba(0,0,255,1)",
      data: xyValues
    }]
  },
  options:{...}
});

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>
<canvas id="myChart" style="width:100%;max-width:700px"></canvas>

<script>
const xyValues = [
  {x:50, y:7},
  {x:60, y:8},
  {x:70, y:8},
  {x:80, y:9},
  {x:90, y:9},
  {x:100, y:9},
  {x:110, y:10},
  {x:120, y:11},
  {x:130, y:14},
  {x:140, y:14},
  {x:150, y:15}
];

new Chart("myChart", {
  type: "scatter",
  data: {
    datasets: [{
      pointRadius: 4,
      pointBackgroundColor: "rgb(0,0,255)",
      data: xyValues
    }]
  },
  options: {
    legend: {display: false},
    scales: {
      xAxes: [{ticks: {min: 40, max:160}}],
      yAxes: [{ticks: {min: 6, max:16}}],
    }
  }
});
</script>

</body>
</html>

Graphiques linéaires

Prix des maisons par rapport à la taille

Code source

const xValues = [50,60,70,80,90,100,110,120,130,140,150];
const yValues = [7,8,8,9,9,9,10,11,14,14,15];

new Chart("myChart", {
  type: "line",
  data: {
    labels: xValues,
    datasets: [{
      backgroundColor:"rgba(0,0,255,1.0)",
      borderColor: "rgba(0,0,255,0.1)",
      data: yValues
    }]
  },
  options:{...}
});

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>
<canvas id="myChart" style="width:100%;max-width:600px"></canvas>

<script>
const xValues = [50,60,70,80,90,100,110,120,130,140,150];
const yValues = [7,8,8,9,9,9,10,11,14,14,15];

new Chart("myChart", {
  type: "line",
  data: {
    labels: xValues,
    datasets: [{
      fill: false,
      lineTension: 0,
      backgroundColor: "rgba(0,0,255,1.0)",
      borderColor: "rgba(0,0,255,0.1)",
      data: yValues
    }]
  },
  options: {
    legend: {display: false},
    scales: {
      yAxes: [{ticks: {min: 6, max:16}}],
    }
  }
});
</script>

</body>
</html>

Si vous définissez borderColor sur zéro, vous pouvez disperser un nuage de points sur le graphique linéaire :

borderColor: "rgba(0,0,0,0)",

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>
<canvas id="myChart" style="width:100%;max-width:600px"></canvas>

<script>
const xValues = [50,60,70,80,90,100,110,120,130,140,150];
const yValues = [7,8,8,9,9,9,10,11,14,14,15];

new Chart("myChart", {
  type: "line",
  data: {
    labels: xValues,
    datasets: [{
      fill: false,
      lineTension: 0,
      backgroundColor: "rgba(0,0,255,1)",
      borderColor: "rgba(0,0,0,0)",
      data: yValues
    }]
  },
  options: {
    legend: {display: false},
    scales: {
      yAxes: [{ticks: {min: 6, max:16}}],
    }
  }
});
</script>

</body>
</html>

Plusieurs lignes

Code source

const xValues = [100,200,300,400,500,600,700,800,900,1000];

new Chart("myChart", {
  type: "line",
  data: {
    labels: xValues,
    datasets: [{
      data: [860,1140,1060,1060,1070,1110,1330,2210,7830,2478],
      borderColor: "red",
      fill: false
    },{
      data: [1600,1700,1700,1900,2000,2700,4000,5000,6000,7000],
      borderColor: "green",
      fill: false
    },{
      data: [300,700,2000,5000,6000,4000,2000,1000,200,100],
      borderColor: "blue",
      fill: false
    }]
  },
  options: {
    legend: {display: false}
  }
});

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>
<canvas id="myChart" style="width:100%;max-width:600px"></canvas>

<script>
const xValues = [100,200,300,400,500,600,700,800,900,1000];

new Chart("myChart", {
  type: "line",
  data: {
    labels: xValues,
    datasets: [{ 
      data: [860,1140,1060,1060,1070,1110,1330,2210,7830,2478],
      borderColor: "red",
      fill: false
    }, { 
      data: [1600,1700,1700,1900,2000,2700,4000,5000,6000,7000],
      borderColor: "green",
      fill: false
    }, { 
      data: [300,700,2000,5000,6000,4000,2000,1000,200,100],
      borderColor: "blue",
      fill: false
    }]
  },
  options: {
    legend: {display: false}
  }
});
</script>

Graphiques linéaires

Code source

const xValues = [];
const yValues = [];
generateData("x * 2 + 7", 0, 10, 0.5);

new Chart("myChart", {
  type: "line",
  data: {
    labels: xValues,
    datasets: [{
      fill: false,
      pointRadius: 1,
      borderColor: "rgba(255,0,0,0.5)",
      data: yValues
    }]
  },
  options: {...}
});

function generateData(value, i1, i2, step = 1) {
  for (let x = i1; x <= i2; x += step) {
    yValues.push(eval(value));
    xValues.push(x);
  }
}

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>

<canvas id="myChart" style="width:100%;max-width:600px"></canvas>

<script>
const xValues = [];
const yValues = [];
generateData("x * 2 + 7", 0, 10, 0.5);

new Chart("myChart", {
  type: "line",
  data: {
    labels: xValues,
    datasets: [{
      fill: false,
      pointRadius: 1,
      borderColor: "rgba(255,0,0,0.5)",
      data: yValues
    }]
  },    
  options: {
    legend: {display: false},
    title: {
      display: true,
      text: "y = x * 2 + 7",
      fontSize: 16
    }
  }
});
function generateData(value, i1, i2, step = 1) {
  for (let x = i1; x <= i2; x += step) {
    xValues.push(x);
    yValues.push(eval(value));
  }
}
</script>

</body>
</html>

Graphiques de fonctions

Identique au graphique linéaire. Modifiez simplement le(s) paramètre(s) generateData :

generateData("Math.sin(x)", 0, 10, 0.5);

Essayez-le vous-même →

<!DOCTYPE html>
<html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.4/Chart.js"></script>
<body>

<canvas id="myChart" style="width:100%;max-width:600px"></canvas>

<script>
const xValues = [];
const yValues = [];
generateData("Math.sin(x)", 0, 10, 0.5);

new Chart("myChart", {
  type: "line",
  data: {
    labels: xValues,
    datasets: [{
      fill: false,
      pointRadius: 2,
      borderColor: "rgba(0,0,255,0.5)",
      data: yValues
    }]
  },    
  options: {
    legend: {display: false},
    title: {
      display: true,
      text: "y = sin(x)",
      fontSize: 16
    }
  }
});
function generateData(value, i1, i2, step = 1) {
  for (let x = i1; x <= i2; x += step) {
    yValues.push(eval(value));
    xValues.push(x);
  }
}
</script>

</body>
</html>