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has anyone used any of the charting tools, like chartjs?



  • i am making a module to add visualization of my friends water well system. I have a mobile app that does this, but it is hard to remember to look at the phone app…

    anyhow, there is a rest api to get the raw measurements (collected at once a minute 24/7)…

    for a 3 day view that is around 4200 entries.



  • Mmm rainfc uses jquery sparkline.

    Mmm-rainfc at git



  • @cirdan thanks… trying to stay away from jquery… and the chartjs works fine with 5 or 10 points…

    i have made some progress. the chart appears and has the right axis labels and values…

    the chart itself is drawn wrong… with the jagged line across the x-axis at the right Y-axis height, being drawn vertically on the right edge of the chart, top to bottom…



  • @sdetweil not too fond of jquery too. Had to add labels in a creative way. But looks like you are on your way to a chartjs implementation. No experience with that. I would like to see the result though. Perhaps I can rewrite mmm-rainfc. Also when you get stuck, a svg solution is also an possibility…user spotyourdeal did a rewrite of the sparkline into svg for mmm-rainfc


  • Project Sponsor

    @sdetweil Well well I was googling “chartjs” about the minute you wrote this down today! Ha! Great.
    I’d like to use it to make some amendments to MMM-rain-forecast and maybe get in my own graph.
    Have you seen MMM-chart, a MM cahrt template, which also seems to have examples of applications like yours.
    I haven’t taken a close look into any of it but I’ll do soon.
    Cheers and good luck!



  • @lavolp3 said in has anyone used any of the charting tools, like chartjs?:

    MMM-chart,

    thanks… my data does not come back in JSON… but as CSV. with a unix milliseconds timestamp.

    one data set is a float value (could be truncated to int), one is an int.



  • ok, well, this was user error…

    while I had an array for time based points, ONE element in the array was JUST a single value.

    this caused the charting tool to act weird…

    fixing the one data point resolved the issue…

    now, I want to change the color of the fill area under certain conditions (low reservoir, or constant running water) to alert about trouble to be resolved…looks like that is some custom extension i have to write…



  • here are some pics of the two charts

    two charts upper right

    two

    two charts closer view
    two closer

    one chart
    one chart


  • Project Sponsor

    @sdetweil Looking good! How did you realize it? MMM-Chart? Chartjs and your own module?



  • @lavolp3 using chartjs and my own module. my data is not in JSON format required by MMM-Charts

    here is the chartjs code
    i have an structure, with arrays of points (by the sensor value), javascript Date, and value.
    there are also arrays that contain the axis labels.

    make div for chart
    	var c = document.createElement("div");	
    	c.style.width=self.config.width+"px";
      	c.style.height=self.config.height+"px";
    	if(!self.config.stacked)
    	   c.style.display='inline-block';
    	self.wrapper.appendChild(c);
    
            canvas= document.createElement("canvas");
     	canvas.id="myChart"+this_pin;
            c.appendChild(canvas);
    
    for(var pin_index=0; 
          pin_index < self.config.Pins.length;  (how do you do less than in markup?, space after < )
          pin_index++)
    {
    var this_pin=self.config.Pins[pin_index];
    
           self.charts[pin_index] = new Chart(canvas, {
                  type: 'line',
                  showLine: true,							
                  data: {
                    datasets: [
                      {
    		    xAxisID: 'dates',
                        data: self.data[this_pin], 
                        fill:true,
                        borderColor: '#2196f3', 
       		    backgroundColor: '#2196f3', 
    	             },
                    ]
                  },
                  options:	 { 
    			legend: { display: false},
    			tooltips: {
    			    enabled: false,
    			    displayColors: false
    			  },
    			responsive: false,
    			elements: {
    			    point: { radius: 0 },
    			    line: {
            		        tension: 0, // disables bezier curves
    			     }
            		},
                    scales: {
                      xAxes: [{
    			id: 'dates',
                        type: 'time',
    			distribution: 'linear',
                        scaleLabel: {
                            display: true,
                            labelString: self.config.labels[pin_index]+" - last "+self.config.dayrange+" days",
    			fontColor: 'white'
                        },
    			gridLines: {
    				display: false,
    				zeroLineColor: '#ffcc33'
    			},
      		        time: {
          		              unit: 'minute'
              		      },
    			bounds: 'data',
                        ticks: {
    			display: false ,
    			maxRotation: 90,
    			source: 'data',
    			maxTicksLimit: self.data[this_pin].length,                    },
                      }],
                      yAxes: [{
                            display: true,
                            scaleLabel: {
                                display: true,
                                labelString: self.config.yaxis_legend[pin_index],
    			    fontColor: 'white'
                            },
    			gridLines: {
    			   display: true,
    			   color: "#FFFFFF",
    			   zeroLineColor: '#ffcc33',
    			   fontColor: 'white',									 
                               scaleFontColor: 'white',
    			},
    
                        ticks: {
    			beginAtZero: true,
    			source: 'data',
                            min: 0,
    			fontColor: 'white'
                        },
                        }]
                    },
                  }
                });
    }