Google Charts - ScatterChart Tick Marks and Styling

Question

I created a ScatterChart to visualize relationships between different data-fields. The visualized data can be numeric or nominal/ordinal in nature. The nominal/ordinal values are therefore mapped to numeric values. A simple example would be "Age + Gender", where gender is nominal and I map 'male' => 1, 'female ' => 2 to get the desired output.

example of what currently happens

So far so good, chart is working, but I need help formatting it.

As you can see the first gender column is displayed on the y axis and the second one at the far right side of the graph. I would like them to be layed out "pretty" as in some space to the y-axis, some space to the right end.

Also I would like to display the appropriate tick marks for "male" and "female" on the y-axis.

EXTENSION:

I also want to split the data into different series to be able to colorize e.g. 'male' and 'female' data points in different colors.

What I do is build 3 columns in my data-table (age, male, female), but I can't quite get it to output correctly. Currently it's all merging into one displayed column.

Here's my Code so far:

var drawMe = function(){
       var columns = 0;
       var xColumns = 0;
       var yColumns = 0;
       var gdata = new google.visualization.DataTable();
       /**
        * data Object:
        * data.xName = Name of x parameter
        * data.yName = Name of y parameter
        * data.x = data for x paramter
        * data.y = data for y parameter
        * data.xType = type of x parameter, either num (= number) or other (= string)
        * data.yType = type of y parameter, either num (= number) or other (= string)
        * data.xChoices = array of strings representing availble choices for x if xType !== num
        * daty.yChoices = array of strings representing availble choices for y if yType !== num
        * 
        */
       if(data.xType === 'num'){
           gdata.addColumn('number', data.xName);
           xColumns++;
           columns++;
       } else {
           for(var i = 0; i < data.xChoices.length; i++){
               gdata.addColumn('number', data.xChoices[i]);
               xColumns++;
               columns++;
           }
       }
       if(data.yType === 'num'){
           gdata.addColumn('number', data.yName);
           yColumns++;
           columns++;
       } else {
           for(var i = 0; i < data.yChoices.length; i++){
               gdata.addColumn('number', data.yChoices[i]);
               columns++;
               yColumns++;
           }
       }
       var x;
       var y;
       for(var i = 0; i < count; i++){ // count is set by closure, cause data is paged via ajax
           // initialize zero row
           var row = [];
           for(var j = 0; j < columns; j++){
               row[j] = null;
           }
           if(data.xType === 'num'){
               x = parseFloat(data.x[i]);
               row[0] = x;
           } else {
               var index = data.xChoices.indexOf(data.x[i]);
               x = {
                   v: index + 1, // don't start at 0
                   f: data.xChoices[index],
               };
               row[index] = x;
           }
           if(data.yType === 'num'){
               y = parseFloat(data.y[i]);
               row[xColumns] = y;
           } else {
               var index = data.yChoices.indexOf(data.y[i]);
               y = {
                   v: index + 1, // don't start at 0
                   f: data.yChoices[index],
               };
               row[xColumns + index] = y;
           }
           gdata.addRow(row);
       }
       var xTitle = data.xName;
       if(data.xUnit){
           xTitle += ' [' + data.xUnit + ']';
       }
       var yTitle = data.yName;
       if(data.yUnit){
           yTitle += ' [' + data.yUnit + ']';
       }
       var xGridLines = -1;
       var yGridLines = -1;
       var xTicks = false;
       var yTicks = false;
       if(data.xType !== 'num' && data.xChoices){
           xGridLines = data.xChoices.length + 2;
           xTicks = [{v: 0, f: ''}]; // empty tick at the beginning
           for(var i = 0; i < data.xChoices.length; i++){
               xTicks.push({v: i+1, f: data.xChoices[i]});
           }
           xTicks.push({v: 3, f: ''}); // empty tick at the end
       }
       if(data.yType !== 'num' && data.yChoices){
           yGridLines = data.yChoices.length + 2;
           yTicks = [{v: 0, f: ''}];
           for(var i = 0; i < data.yChoices.length; i++){
               yTicks.push({v: i+1, f: data.yChoices[i]});
           }
           yTicks.push({v: 3, f: ''});
       }
       var options = {
         title: data.xName + ' vs. ' + data.yName,
         hAxis: {
             title: xTitle,
             gridlines: {
                 count: xGridLines
             }
         },
         vAxis: {
             title: yTitle,
             gridlines: {
                 count: yGridLines
             }
         }
       };
       if(xTicks !== false){
           options.hAxis.ticks = xTicks;
           options.hAxis.viewWindowMode = 'pretty';
       }
       if(yTicks !== false){
           options.vAxis.ticks = yTicks;
           options.vAxis.viewWindowMode = 'pretty';
       }
       options.series = {};
       for(var i = 0; i < columns; i++){
           options.series[i] = {color: atk.COLORS[i], visibleInLegend: true};
       }
       var chart = new google.visualization.ScatterChart(element);
       chart.draw(gdata, options);
   };

Thanks for your help and time!

asgallant asgallant · Accepted Answer · 2013-08-19T18:02:28

You're in luck, there is an update to the API that is in the RC version (1.1) that should be able to do exactly what you want. Load the RC version first:

google.load('visualization', '1.1', {packages: ['corechart']});

Then set the hAxis.ticks option like this:

hAxis: {
    ticks: [{v: 0, f: ''}, {v: 1, f: 'Male'}, {v: 2, f: 'Female'}, {v: 3, f: ''}]
}

Try that and see if it works.

Edit:

To make the males and females different colors, you need to split the data into two separate columns. You can accomplish this by using a DataView:

// assumes Male/Female is column 0 and age is column 1 in your DataTable
var view = new google.visualization.DataView(data);
view.setColumns([0, {
    type: 'number',
    label: 'Age',
    calc: function (dt, row) {
        // return a value only if male
        return (dt.getValue(row, 0) == 1) ? dt.getValue(row, 1) : null;
    }
}, {
    type: 'number',
    label: 'Age',
    calc: function (dt, row) {
        // return a value only if female
        return (dt.getValue(row, 0) == 2) ? dt.getValue(row, 1) : null;
    }
}]);

Draw the chart using the DataView instead of the DataTable.

Google Charts - ScatterChart Tick Marks and Styling

1 Answers