Question

I'm trying to draw a chart from 1 series with 1440 points (24 hours), each point has own color. I was able to draw it with a hook, described here, but I'm getting ugly border and shadow on the line. I'm also not able to fill the space between x-axis and the line. Plot doesn't also read these options:

var plot = $.plot(
        $('.LCGraph'),[
            {
                data: d2, 
                points: {
                    show: true
                }
            }
        ],{
            grid: {
                 hoverable: false,
                 clickable: false,
                 borderWidth: {
                             top: 0.1, 
                             right: 0.1, 
                             left: 0.1, 
                             bottom: 0.1
                         },
                 borderColor: {
                             top: "#AAAAAA", 
                             left: "#AAAAAA", 
                             right:"#AAAAAA",
                             bottom:"#AAAAAA"
                         },
        },  
            bars: {
                show: false
            },
            xaxis: {
                show: true
            },
            hooks: {
                draw: [raw]
            }
        });

How can I solve this problem?

P.S. This hook was used:

$(function () {

  var d2 = [[0, 3], [4, 8], [8, 5], [9, 13]];
  var colors = ["#cc4444", "#ff0000", "#0000ff", "#00ff00"];
  var radius = [10, 20, 30, 40];

  function raw(plot, ctx) {
    var data = plot.getData();
    var axes = plot.getAxes();
    var offset = plot.getPlotOffset();
    for (var i = 0; i < data.length; i++) {
        var series = data[i];
        for (var j = 0; j < series.data.length; j++) {
            var color = colors[j];
            var d = (series.data[j]);
            var x = offset.left + axes.xaxis.p2c(d[0]);
            var y = offset.top + axes.yaxis.p2c(d[1]);
            var r = radius[j];                
            ctx.lineWidth = 2;
            ctx.beginPath();
            ctx.arc(x,y,r,0,Math.PI*2,true);
            ctx.closePath();            
            ctx.fillStyle = color;
            ctx.fill();
        }    
    }
  };  

    var plot = $.plot(
          $("#placeholder"),
          [{ data: d2, points: { show: true } }],
          { hooks: { draw  : [raw] } }
  );  
});
Was it helpful?

Solution

Just in case somebody looks for a solution.

I have overwritten the hook to manually draw lines to X-Axis.

function raw(plot, ctx) {
    var data = plot.getData();
    var axes = plot.getAxes();
    var offset = plot.getPlotOffset();
    var bottom = axes.yaxis.p2c(0)+offset.top;
    for (var i = 0; i < data.length; i++) {
        var series = data[i];
        for (var j = 0; j < series.data.length; j++) {
            var color = colors[j];
            var d = (series.data[j]);
            var x = offset.left + axes.xaxis.p2c(d[0]);
            var y = offset.top + axes.yaxis.p2c(d[1]);
            var r = 0.9;
            ctx.lineWidth = 0.4;
            ctx.strokeStyle = color;
            ctx.beginPath();
            ctx.arc(x,y-r,r,0,Math.PI*2,true);
            ctx.closePath();
            ctx.fillStyle = color;
            ctx.fill();
            ctx.shadowSize = 0;
            ctx.beginPath();
            ctx.moveTo(x,y);
            ctx.lineTo(x, bottom);
            ctx.stroke();
            ctx.closePath();
            ctx.fill();
        }
    }
}

Maybe it can be optimized, but it works as it should. To prevent this ugly color of flot I've changed the options of plot to hide the actual graph:

var plot = $.plot(
        $('#graphContainer'),[
            {
                data: d2, 
                points: {
                    show: true
                }
            }
        ],{series:{
            shadowSize: 0,
            color: "rgba(0,0,0,0)",
            lines: {
                lineWidth: 0.1,
            fill: false,
                show: false,
                color: "rgba(0,0,0,0)"
            },
            points: {
                shadowSize: 0,
                lineWidth: 0.1,
                fill: false,
                show: false,
                color: "rgba(0,0,0,0)"
            }
        },
            grid: {
                 backgroundColor: "#F1F1F1",
                 hoverable: false,
                 clickable: false,
             borderWidth: {top: 0.1, right: 0.1, left: 0.1, bottom: 0.1},
             borderColor: {
                        top: "#AAAAAA", 
                        left: "#AAAAAA", 
                        right:"#AAAAAA",
                        bottom:"#AAAAAA"
                 },
            },
            bars: {
                show: false
            },
            xaxis: {
                show: true,
            },
            hooks: {
               draw: [raw]
            }
        }); 

So you need d2-Array with your data and colors-Array with colors for each point. The length of d2 and colors should be the same. You can also change the value of var r and ctx.lineWidth in function raw(plot, ctx) to get your wanted appearance.

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