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javascriptchart.jsburndowncharts

Calculate Ideal Burndown

I am trying to draw a Burndowm chart form a data API.

I have successfully retrieved the data etc.

I now need to draw an ideal Burndown line. This will be from the full sprint estimate number, down to zero. I am using Chart.js to draw the line graph.

I have tried to calculate each day's ideal total using the following code:

var totalSprintEstimate = 148.5;
var totalDays = 10; 
var idealIncrement = totalSprintEstimate / totalDays;
var ideal = [];
for (i = 0; i <= totalDays-1; i++) {
    ideal.push(idealIncrement * i);
}
ideal.reverse();

With this logic, I always end up one day short of a full total (133 point something) against totalDays = 10-1 or I reach the full 148.5 but with too many days to plot on the graph.

I have tried to look this up on t'internet but have come to a halt as I don't really know what to search for.

Solution

  • Well, of course you end up one increment short, because you shift to a zero based index and multiply with that.

    Your first iteration is 

    ideal.push(idealIncrement * 0);

    robbing you of your first increment.

    change

    ideal.push(idealIncrement * i);

    to

    ideal.push(idealIncrement * (i+1));

    and you should be able to go on with your current strategy. Or, which is better to read, start your for loop at i=1 and go all the way up to totaldays, that works fine too. No need to start at 0 since you don't access the array index anywhere in that loop.