Develop Reference

Append data count onto different series

I have 2 datatime series (A & B)
Xaxis should be time and yaxis is count.
If time t i have 1 value on serie A, graph will show: [x=t, y=1].
If same time t i have one other value on serie B, I would like that value to be show: [x=t, y=2].
At the moment I modify 'manualy' values on serie B.
I wonder if there os a built-in method in highcharts to have that behavior?
Thx

Ok, so in that case you would have to create some custom code that gets all data, checks for occurrences of the same dates and based on that information set appropriate y values for points. I have prepared a simple demo where all emails are correctly arranged on the chart.
Example:
https://jsfiddle.net/BlackLabel/ywsh98f5

Highcharts Y-Axis Limits

I am having problems controlling the Y-Axis range of a highcharts graph. It seems like highcharts likes nice round numbers. When my data passes or is close to certain thresholds, the Y-Axis range can expand a lot which effectively compresses all the plot points downward.
Here is a jsfiddle that illustrates the problem I am having:
https://jsfiddle.net/shannonwrege/z8h5eork
The relevant code for this post is this:
chart.yAxis[0].setExtremes(0, max, true, false);
Keep in mind that I don't know what the data will look like in advance, so I must dynamically modify the Y-Axis range. Right now I am using the setExtremes because of other suggestions I've read on stackoverflow.
The maximum y-value of the data in the first two charts is 99. You'll notice that the y-axis is set at 150 in the first chart where the range is automatically calculated and 100 in the second chart where I specifically set the extreme values. The look of the 2nd chart is what I want. So it seems like setExtremes(0,99,true,false) should do the trick, but it actually doesn't.
In the 3rd chart I changed the data so that the maximum y-value of the data is 101, and I called setExtremes(0,101,true,false). You'll note that the y-axis is now back to 150.
Ideally I want the scale of the graph to be capped on the maximum value to limit the about of extra white space. I want to see all of the data, but I don't necessarily care about the y-axis displaying a maximum band that is greater than the max data value. In this case, I would be happy with the y-axis displaying 100 on the axis and some points over but still visible.
Does anyone know how to make this work?

I ended up using the endOnTick parameter to solve this problem. Adding the following line to the yAxis configuration parameters did exactly what I wanted:
endOnTick: false,
Here's the updated Fiddle showing the results.
https://jsfiddle.net/shannonwrege/z8h5eork/3/
All of the charts look pretty good in my opinion (even the one where the yAxis range was auto calculated).

You will need to read the data and then round up to set the idealMax
var chart,
idealMax = 0; // init the max value
// Read the data to find the highest value
for (i=0;i < (options.series[0].data).length; i++ ){
if (options.series[0].data[i][1] > idealMax) {
idealMax = options.series[0].data[i][1];
}
}
// Round the max to the nearest 10
idealMax = Math.round(idealMax / 10) * 10;
options.yAxis.tickPixelInterval = idealMax/10;
Highcharts.chart('container1', options);
chart = $('#container1').highcharts();
chart.yAxis[0].setExtremes(0, idealMax, true, false);
Updated Fiddle

chart.js radar scaleShowLine for each scaleLine

I'm working on a radar chart and I would like to only show the last scaleline.
I found this post which could have helped me: Chart.js (Radar Chart) different scaleLineColor for each scaleLine but unfortunately, the answer is not working anymore (the jsfiddle link doesn't display anything).
I read parts of the chart.js documentation about gridLines option, then did some tests/changes on this code: [regular radar chart][2] without any result, would anyone know how to adjust it?
Thanks!
[2]: https://codepen.io/grayghostvisuals/pen/xmBpLenter code here

Here is a solution using the latest version of chart.js (v2.5.0). It uses the scale afterTickToLabelConversion callback property to overwrite the values that were set for the scale ticks (e.g. scale lines).
Since you only want to display the last line, you have to overwrite them by keeping the first tick value (which is never displayed) and only the last tick value (the last line). If you only wanted to display some other line then you would keep the first tick and only the other line that you want displayed.
Here is my implementation.
afterTickToLabelConversion: function(scaleInstance) {
// overwrite the ticks and keep the first (never shown) and last
var oldTicks = scaleInstance.ticks;
scaleInstance.ticks = [oldTicks[0], oldTicks[oldTicks.length - 1]];
// overwrite the numerical representation of the ticks and
// keep the first (never shown) and last
var oldTicksAsNumbers = scaleInstance.ticksAsNumbers;
scaleInstance.ticksAsNumbers = [oldTicksAsNumbers[0], oldTicksAsNumbers[oldTicksAsNumbers.length - 1]];
}
Here is a codepen example that shows an original radar chart and one using the approach described above so that you can see the difference.

Fit the cumulative percentage line to the sorted histogram output with d3 for a pareto chart histogram

This is what I have so far: https://gist.github.com/daluu/fc1cbcab68852ed3c5fa and http://bl.ocks.org/daluu/fc1cbcab68852ed3c5fa. I'm trying to replicate Excel functionality.
The line fits the default histogram just fine as in the base/original http://bl.ocks.org/daluu/f58884c24ff893186416. And I'm able to sort the histogram in descending frequency, although in doing so, I switched x scales (from linear to ordinal). I can't seem to map the line to the sorted histogram correctly at this point. It should look like the following examples in terms of visual representation:
the Excel screenshot in a comment in my gist referenced above
the pareto chart sorted histogram in this SO post
the pareto chart (similar to but not exactly a sorted histogram) made with d3 here
What's the best design approach to get the remaining part working? Should I have started with a single x scale and not need to switch from linear to ordinal? If so, I'm not sure how to apply the histogram layout correctly using an ordinal scale or how not to use a linear x scale as a source of input to the histogram layout and still get the desired output.
Using the same ordinal scale with the code I have so far, the line looks ok but it's not the curve I am expecting to see.
Any help appreciated.

The main issue with the line is that the cumulative distribution needs to be recalculated after the bar is sorted, or if you're gunning for a static pareto chart, the cumulative distribution needs to be calculated in the target sort order. For this purpose i've created a small function to do this calculation:
function calcCDF(data){
data.forEach(function(d,i){
if(i === 0){
d.cum = d.y/dataset.length
}else{
d.cum = (d.y/dataset.length) + data[i-1].cum
}
})
return data
}
In my case, i'm toggling the pareto sort on/off and recalculating the d.cum property each time. One could theoretically create two cumulative dist properties to start with; i.e. d.cum for a regular ordered distribution and say d.ParetoCum for the sorted cumulative, but i'm using d.cum on a tooltip and decided against that.
Per the axis, i'm using a single ordinal scale which i think is cleaner, but required some work on getting the labels to be meaningful for number ranges since tick-marks and labels no longer delineate the bins as one would get with a linear scale. My solution here was to just use the number range as the tick mark e.g. "1 - 1.99" and add a function to alternate tickmarks (got that solution a while ago from Alternating tick padding in d3.js).
For the bar sorting, i'm using this d3 example as a reference in case you need to understand in the context of a simpler/smaller example.
See this fiddle that incorporates all of the above. If you want to use it, i would suggest adding a check to avoid the user being able to toggle off both bars and line (left a note in the code...should be trivial)

Instead of sorting the y.
data.sort(function(a,b){ return b.y - a.y;});
you should be sorting the x
data.sort(function(a,b){ return a.x - b.x;});
Working code here

Nvd3 multibarcharts - display gaps in the data on the xAxis

I just started using nvd3 a short while ago and am now facing a big problem for me with multibar charts:
My xAxis data has gaps in between, e.g. [1,2,3,4,9,24,120].
I want these gaps to be displayed in the graph, but nvd3 just displays all bars next to each other, so, that the distance between the bars with the x value 2 and 3 is the same as between those with 9 and 24.
Is there any way to change this, so that you can see all the gaps in the data?
The code I used is just the same as nvd3s example code.
Thank you very much.

Sure there is. You will fill in 0 for all the missing values. For each y that will correspond to a missing value you will set x = 0. That's all you need to do (it's not as simple as it sounds since there can be cases with series which have no data and so on, but this is the main trick).