voici mon code. J'ai besoin de définir la valeur initiale comme "0" dans les échelles des axes x et y. J'ai essayé la dernière option d'échelles de version.
graphOptions = {
///Boolean - Whether grid lines are shown across the chart
scaleShowGridLines: false,
tooltipTitleTemplate: "<%= label%>",
//String - Colour of the grid lines
scaleGridLineColor: "rgba(0,0,0,.05)",
//Number - Width of the grid lines
scaleGridLineWidth: 1,
//Boolean - Whether to show horizontal lines (except X axis)
scaleShowHorizontalLines: true,
//Boolean - Whether to show vertical lines (except Y axis)
scaleShowVerticalLines: true,
//Boolean - Whether the line is curved between points
bezierCurve: true,
//Number - Tension of the bezier curve between points
bezierCurveTension: 0.4,
//Boolean - Whether to show a dot for each point
pointDot: true,
//Number - Radius of each point dot in pixels
pointDotRadius: 4,
//Number - Pixel width of point dot stroke
pointDotStrokeWidth: 1,
pointHitDetectionRadius: 20,
datasetStroke: true,
datasetStrokeWidth: 2,
datasetFill: true,
legendTemplate: "<ul class=\"<%=name.toLowerCase()%>-legend\"><% for (var i=0; i<datasets.length; i++){%><li><span style=\"background-color:<%=datasets[i].strokeColor%>\"></span><%if(datasets[i].label){%><%=datasets[i].label%><%}%></li><%}%></ul>"
};
var LineChart = new Chart(ctx).Line(graphData, graphOptions);
}