Need some help regarding my usage scenario

[souravndp]

I am trying to display live bandwidth utilization using canvas JS. I have faced some difficulties to implement the CanvasJS library. Please help with the followings. Thank you.

1. https://jsfiddle.net/2jhaL9qk
This is the basic implementation. I am just pushing the new data points (x: timestamp and y: a random number). I am not using any initial data points. Everything works fine except during the first few seconds, the x-axis labels do not make sense. (Please increase the result tab area in JSfiddle)

2. I tried to fix the long random number and tried rounding it with 2 digits after decimal points. In the above JSfiddle, line 66-67, I used .toFixed(2) but the graph plot disappeared.

yValue1=getRandom(0,30).toFixed(2)
yValue2=getRandom(0,30).toFixed(2)

3. https://jsfiddle.net/1vwgkmcn/3/
I tried to display the live statistics only for the last 1 minute. I used chart.options.axisX.viewportMinimum = (time.getTime()-60000); (at line 76 of the above JSfiddle) everytime I pushed a data point.
3.a) Is there any better option to achieve this?
3.b) manual select and zoom feature is buggy (it changes every time the viewport is changed, which is every 1 sec in my case). Can it be fixed? If not, I want to remove the pan, zoom, reset buttons from the top. How to remove them?
3.c) In the first second, the x-axis is inverted. How can I fix it?

[souravndp]

I have solved 2 and 3.
.toFixed converts the number to sting. so, the chart rendering fails.
Also, the correct way to display a live data is to use shift method on the datapoint array. This is mentioned in the Docs

But I am still struggling with the 1st issue. The first point has the correct time axis. Then, for 10 seconds some ms is getting displayed and then again correct date-time is being displayed.

I am using the following hack to overcome this behavior. If the datapoint array length is 0, I am adding 2 more data points. 1. (x: 10 sec ago and y: 0) This does not look good because of the line continuity. Thus I am also adding 2. (x: 10 ms ago and y: 0)

if(dataPoints1.length==0){
		dataPoints1.push({
		x: new Date(Date.now() - 10000),
		y: 0
		});
	dataPoints2.push({
		x: new Date(Date.now() - 10000),
		y: 0
		});
		dataPoints1.push({
		x: new Date(Date.now() - 100),
		y: 0
		});
	dataPoints2.push({
		x: new Date(Date.now() - 100),
		y: 0
		});
	}

• This reply was modified 6 years, 1 month ago by souravndp. Reason: added some more clarification

[Priyanka M S]

@souravndp,

1. https://jsfiddle.net/2jhaL9qk
This is the basic implementation. I am just pushing the new data points (x: timestamp and y: a random number). I am not using any initial data points. Everything works fine except during the first few seconds, the x-axis labels do not make sense. (Please increase the result tab area in JSfiddle)

You can use valueFormatString to define the format of values / labels displayed on axis X and this should work fine in this case. Please take a look at this updated jsfiddle for the same.

Glad that you solved the other issues with the help of our documentation.

__
Priyanka M S
Team CanvasJS

[souravndp]

Thank you very much :) Now, its perfect. CanvasJS really has a great documentation and support. This topic can be closed.