Plotting multiple lines (line chart) in Apache Zeppelin using AngularJS

Question

I am trying to plot multiple line Charts in Apache Zeppelin using Angular Js and Chart JS. i am binding an array in the Scala Paragraph in the format {epoch, id, label, score, tweet_count}. The objective is for every id, there will be a different set of values. on running the code i am having two different graphs (on hovering mouse). i would like to have 1 graph. For instance, for id 1,2 i would like to plot a score graph in the same canvas and not want it overlapped.

angular.forEach(newValue, function(x) {  
    lineChartData = {}; //declare an object
    lineChartData.labels = []; //add 'labels' element to object (X axis)
    lineChartData.datasets = []; //add 'datasets' array element to object


  for(line=0; line < 2; line++) {

            y = [];
            lineChartData.datasets.push({}); //create a new line dataset
            dataset = lineChartData.datasets[line]
            dataset.data = []; //Y axis data

            angular.forEach(newValue, function(x) {
                   if(myLineChart != null && myLineChart !== undefined)
        myLineChart.destroy();

                if (line === 0 ) {  

                   // console.log("Value of x: ",x)

                    //adds data to y axis
                    lineChartData.labels.push(x._3) //adds x axis labels

                    dataset.fillColor = "rgba(0, 0, 0, 0)";
                    dataset.strokeColor = "rgba(75,192,192,0.4)";
                    dataset.lineColor = "rgba(75,192,192,0.4)";
                    dataset.label = "Score"
                    y.push(x._4); //y axis value


                }

                lineChartData.datasets[line].data = y;   

             })
         }

    })

This is my code which plots the graph, but i would like to plot different lines for each id in the same canvas.

Answer 1

We can do a model transformation from one DataSource (for example Spark DataFrame) to the Chart's model which %angular supported by Zeppelin. You can doing similar like this SO create a multi line chart using Chart.js

If doing this way, then every time when we want to change to a different model. We have to do copy & paste work. It will be easier if there is a general model transformation.

I created a repo on github spark-highcharts for plot easily for spark DataFrame with Highcharts. You can plot with spark-highcharts after doing a simple transformation from Scala collection to Spark DataFrame if you could accept using Highcharts.

Like the following code to create multiline chart.

import com.knockdata.spark.highcharts._
import com.knockdata.spark.highcharts.model._
import sqlContext.implicits._

val Tokyo = Seq(7.0, 6.9, 9.5, 14.5, 18.2, 21.5, 25.2, 26.5, 23.3, 18.3, 13.9, 9.6)
    .map(("Tokyo", _))
val NewYork = Seq(-0.2, 0.8, 5.7, 11.3, 17.0, 22.0, 24.8, 24.1, 20.1, 14.1, 8.6, 2.5)
  .map(("New York", _))
val Berlin = Seq(-0.9, 0.6, 3.5, 8.4, 13.5, 17.0, 18.6, 17.9, 14.3, 9.0, 3.9, 1.0)
  .map(("Berlin", _))
val London = Seq(3.9, 4.2, 5.7, 8.5, 11.9, 15.2, 17.0, 16.6, 14.2, 10.3, 6.6, 4.8)
  .map(("London", _))

val dataFrame = (Tokyo ++ NewYork ++ Berlin ++ London).toDF("city", "temperature")

val chart = highcharts(dataFrame
  .seriesCol("city")
  .series("y" -> col("temperature")))

chart.plot()

And the API is pretty similar between Highcharts and ChartJS. A similar library could be done to transform from Scala collection to ChartJs similar like spark-highcharts does.