Javascript charts, custom step amount, but equally divided over available space - javascript

I'm looking for a javascript chart library where I can set custom step size.
I want a bar chart, where certain values are more important than others.
I'd like to have the ticks like [0, 50, 90, 99, 100]. And have the space between those values the same. I've tried Google Charts and Chartist, but they all put 99 and 100 very close to eachother, but I want it equally divided.
This is the idea:
Anyone ideas how to achieve this?

If these are your domain values, then provide them as strings instead of numbers. Then they will be evenly distributed.
But if these are your target or range values, you'll have to do something trickier. You'll have to use integer values like 0 through 4, and then use the explicit ticks option for the vAxis to specify both the values and how to display them.

Related

Override auto generated Y axis plot area values in Highcharts

I have certain requirement where I need to override the auto calculated values for Y axis in highcharts. For eg.
Here, the gridlines plot area is equally divided into 100. I wanted to override this so that the negative plot area should be at a max of let's say 50 and the positive ones can remain the same. Even if I try the max, min, softMax, softMin, ceiling and floor properties, the result is the same. I was thinking of using a secondary axis but then there is only one data in the series which would render the second one useless. I don't think using setExtremes() will be helpful either. I'm hoping to avoid modifying the library itself to add a certain option but it'll be helpful if such an option already exists in highcharts. Any suggestions?
Use tickPositions or tickPositioner property:
yAxis: {
tickPositions: [-50, 0, 100, 200, 300, 400]
}
Live demo: http://jsfiddle.net/BlackLabel/6m4e8x0y/4883/
API Reference:
https://api.highcharts.com/highcharts/yAxis.tickPositions
https://api.highcharts.com/highcharts/yAxis.tickPositioner

Highcharts heatmap logarithmic colorAxis fails when 0

I'm trying to implement a heatmap in highcharts with a logarithmic colorAxis, however, I keep getting highcharts error #10 (can't plot zero or subzero values on a logarithmic axis).
As I'm trying to apply the logarithmic property to the color axis and not the actual axis themselves, I believe my problem is caused by some of my bins having a frequency of zero (A heatmap colors by the frequency in each bin).
How can I get around this? Can I create a default function so that when a frequency is zero it assigns that bin a default color? I can't find any solutions in the docs.
Currently, my colorAxis object looks like this
colorAxis: {
type: 'logarithmic',
minColor: '#EEEEFF',
maxColor: '#000022',
stops: [
[0, '#EFEFFF'],
[0.67, '#4444FF'],
[1, '#000022']
]
}
My solution was to iterate through my data and change all the zeros to an extremely small number then set a min property on the colorAxis so the extremely small numbers would not interfere with the color scheme. This is obviously not the best solution because if the third dimension was measuring something other than frequency and this other thing could be a fraction less than 1 then the extremely small value could overlay with actual data and throw off the color scheme. Hopefully someone comes along and provides a better solution, but for now this is all the insight I have to give.
Logarithm doesn't have any value in 0 so your solution seems pretty neat. You need to apply some offset to the values that equal 0 - there's no other way.
If you want to be more consistent you can apply the offset to all the values. Then apply formatters(tooltip, data labels, color axis' labels) so that the user sees the value without the offset.
Live demo: http://jsfiddle.net/kkulig/jdf5wrdL/

How do we change the tick values generated by a linear scale in a d3.js line plot?

I only had 5 values[1,2,3,4,5] as my y - coordinates in the d3.js line plot. But, I end up getting more values [0.5,1,1.5,2,2.5,3,3.5,4,4.5,5] Is there a way to edit the d3.js file or the html file inorder to plot the values as per my requirement?
The tick marks created by a d3 axis can be controlled in two ways:
Using axis.tickValues(arrayOfValues) you can explicitly set the values that you want to show up on the axis. The ticks are positioned by passing each value to the associated scale, so the values should be within your scale's domain. This works for any type of scale, including ordinal scales, so long as the values you give are appropriate to that scale.
Alternately, using axis.ticks(parameters) you can modify the way the scale calculates tick marks. The types of parameters you can use depends on the type of scale you're using -- the values you specify will be passed directly to the scale's .ticks() method, so check the documentation for each scale type. (Parameters will be ignored for ordinal scales, which don't have a ticks() method.)
For linear scales, the scale.ticks() method accepts a number as a parameter; the scale then generates approximately that many ticks, evenly spaced within the domain with round number values. If you do not specify a tick count, the default is to create approximately 10 ticks, which is why you were getting ticks on 0.5 intervals when your domain was from 0 to 5.
So how do you get the behaviour you want (no decimal tick values)?
Using .tickValues(), you would create an array of unique Y-values to be your ticks:
var yValues = data.map(function(d){return d.y;});
//array of all y-values
yValues = d3.set(yValues).values();
//use a d3.set to eliminate duplicate values
yAxis.tickValues( yValues );
Be aware that this approach will use the specified y values even if they aren't evenly spaced. That can be useful (some data visualization books suggest using this approach as an easy way of annotating your graph), but some people may think your graph looks messy or broken.
Using .ticks(), you would figure out the extent of your Y domain, and set the number of ticks so that you do not have more tick marks then you have integers available on your domain:
var yDomain = yScale.domain();
yAxis.ticks( Math.min(10, (yDomain[1] - yDomain[0]) );
This will create the default (approximately 10) ticks for wide domains, but will create one tick per integer value when the difference between the max and min of your domain is less than 10. (Although the tick count is usually approximate, the scale will always prefer integer values if that matches the tick count specified.)
Yes you can also try
yAxis.ticks(5).tickFormat(D3.numberFormat(",d"));
It does the trick of eliminating the decimal numbers, does not effect number of ticks
Here is a good resource for the format of the numbers using D3.

Rounding y-value labels with Morris.js charts

I have plotted some JSON data using Morris.js. The graph works fine, however I'm trying to tweak the labels along the y-axis in a line chart.
Currently, the yLabels are being automatically generated by morris.js using the JSON data's range of values (where x-axis is time). In my example JSON, values range from 54 to -47, so the yLabels being generated are 54, 29, 4, -22, -47. Instead, however, I'd like to round these values to -50, -25, 0, 25, and 50. I would also like the "0" line to stand out, hopefully with a different colour.
As I'm dynamically creating the data, these won't be fixed, in another chart the values may range between -2.5 and +2.5 (in which case I'd want the labels along the y axis to be -2.5, -1.25, 0, 1.25, 2.5).
How would I round the labels morris.js is creating and make the "0" line red?
I have tried creating an array of yLabels (yLabels: ['-50','-25','0','25','50'],), but it didn't work, and even if it had I don't want to "hard-code" values because as I said, each chart will be different and dynamically generated.
Any help is greatly appreciated.
UPDATE
In the first example, I have been able to get what I want putting ymin and ymax of -50 and 50 respectively, but like I mentioned, I don't want to hard-code these values as the ymin/max will vary depending on the JSON being parsed. Is there a way I can always ensure the middle line is always 0, and morris determines the two y values above and below it?
I't cannot be done using Morris options. You will have to go into source and change drawGrid() function in morris.grid.coffee file.
I upped the numLines property of the gridDefaults in morris.js and was able to get everything in my Y-Axis to display. Perhaps you could play around with that property to display your Y-Axis differently.

How to break highchart bars for extreme values

In highcharts if there are two series, where the first series value is 20,0000 and the second series value is 20, then the second series becomes so small that it is almost invisible.
Is it possible to break the first bar so that second series become visible? Below is the desired output...
At this time there is not a way to do this.
See the HighCharts User Voice here.
I have used a mathematic calculation in the past to solve this kinds of problems. Here is a couple of different examples:
VALUES: 220, 110, 55, 5
Normal Format
Square Root Format
VALUES: 1100, 220, 110, 55, 5
Normal Format
Square Root Format
What I do in the above examples to get low value series to show more is use the square root of all values. The data is sent as the square root rounded to the third decimal. Then I use the formatter on the yAxis label and tooltip to display the proper values.
Also, in the above examples, I am using whole numbers. When formatting the yAxis label and tooltip I am adding 1 and forcing them to an integer to get them back to the original needed number. This works great for whole numbers. If your data is not a whole number, then you would have to pass the entire result from the square root. Then of course not force it to an int.

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