Chart not rendering with 4 or less data records

[dean]

Time bar chart does not render when there are 4 or less data records. The data unit is months ("M") and I'm getting this warning...

The datasource default cannot return data for unit 1 d

The dates for all data points are first day of the month. Is that the issue? If so, what can I do instead of that?

Example:
DATA:

CHART:

When chartData.preloaded.values has more than 4 members it renders fine. When it's 4 or less, I get the above.

Here is the relevant code. I know it can be improved but I needed to get this working as quickly as possible.

var seriesData = [{
    "name": "Unique Monthly Count",
    "data": {
        "index": 1,
    },
    "style": {
        //"fillColor": colors[i].COLOR,
    },
    "stack": "default",
    "type": "columns"
}];

var chartData={
	preloaded:{
		dataLimitFrom:Date.UTC(2016, 1, 1, 1, 0, 0),
		dataLimitTo:Date.UTC(2018,1,1),
	    unit:"M",
	    "info":["Projected Unique Monthly Counts"],
	    values: [],
	}
};


r.forEach(function(d,i){
		var thisData=[];
		thisData.push(getJSTime(parseInt(d.MONTHNUM)+"/1/"+d.YEARNUM));
		thisData.push(d.PROJECTEDCOUNTS)
		chartData.preloaded.values.push(thisData)
	});

	var chart = new TimeChart({
	    series: seriesData,
	    container: "fancyChart",
	    data:chartData,
	    toolbar: {
	        "fullscreen": true,
	        "enabled": true,
	        displayPeriod: false,
	        logScale:false,
	        zoomOut:false,
	        displayUnit:true
	    },
	    interaction: {
	        "resizing": {
	            "enabled": true
	        }
	    },
	    theme: ZoomCharts.TimeChart.themes.static,
	});
	console.log(chartData);
	});

[dean]

Same code, same data structure, just more records. Chart works as expected.

DATA:

CHART:

[SupportTeam]

Hi,

You should annotate the data source that it is capable of providing data in only months, by adding:

unit: “M”

to the preloaded data (read more here: https://zoomcharts.com/developers/en/time-chart/introductory-topics/data.html#)

Also, you may want to reconfigure the display units: https://zoomcharts.com/developers/en/time-chart/api-reference/settings/area.html#

Janis

[SupportTeam]

Its because with more data it would determine that month is appropriate time unit (based on the min/max width of the time unit under time axis). Consider configuring displayUnits under area configuration (just have month/year). By default it would have day, hour and so forth.

Janis

[dean]

That makes sense. BUT, I DO have the unit specified in the preloaded data.

Here is the object before values are populated:

var chartData={
	preloaded:{
	    dataLimitFrom:Date.UTC(2016, 1, 1, 1, 0, 0),
	    dataLimitTo:Date.UTC(2018,1,1),
	    unit:"M", <----------------------------------------- UNIT IS HERE
	    "info":["Projected Unique Monthly Counts"],
	    values: [],
	}
};

You can see it in the console output as well above. I tried "unit" in quotes as well...no change.

Is there some other area where unit needs to be defined?

[SupportTeam]

So what happens is that, when you have too few data points, the chart falls over to the next display unit, which is day by default, as otherwise the displayUnit width would exceed the limit as provided by timeAxis.

To mitigate this, please either update the maxUnitWith property OR provide the necessary aggregation units in area, like this:

area: {
    displayUnits: [
         {unit: "1 M", name: "month"},
         {unit: "1 y", name: "year"}
    ]
}

Note, that upward aggregation of the data will be done by the chart itself.

Janis
ps.
updated to have the "name" in the area settings as pointed out by Dean.

[dean]

Thank you, that worked. I used the "area" solution that you posted above. For future readers, note that there's a mistake in that code. In the displayUnits array the object properties that need to be set are "unit" and "name." In the post above "name" is missing. It should look like so:

area: {
    displayUnits: [
         {unit: "1 M",name: "month"},
         {unit: "1 y",name: "year"}
    ]
}

Here's what it looks like now with just one record in the data:

It ain't pretty, but it is what it is.

Thanks for the help.

[SupportTeam]

Thanks for noting the missing key. Update the answer.

Janis