I am stuck on a problem here. Could be simple though but i am having a tough time figuring it out. I want to show multiple lines on a dc composite chart.
My data is like this:
{ Name: Mike, mark1: 26.9, mark2: 62.3 },
{ Name: John, mark1: 23.5, mark2: 60.3 },
{ Name: Firen, mark1: 24.3, mark2: 62.5 }
I need the name plotted against X axis and mark1 and mark2 plotted as lines against the Y axis. I found a fiddle here which uses a linear scale to achieve the same result. http://jsfiddle.net/anmolkoul/mzx6mnru/3/
But it uses a linear scale as the base dimension is numerical. My base dimension is a string and hence not working with the same code. I figured it is due to the scale definition that i am using. Here is the fiddle that i need help with: http://jsfiddle.net/anmolkoul/pjLoh1az/1/
I have currently defined my x axis as
.x(d3.scale.ordinal().domain(nameDimension))
.xUnits(dc.units.ordinal)
I think this is where it is going wrong. I have two supplementary questions as well:
Once this is done, how to assign different colors to the lines ( it should reflect in the legend as well)
I was taking a look at the dc.js series chart, what does this line of code do?
runDimension = ndx.dimension(function(d) {return [+d.Expt, +d.Run]; });
Does it pivot the two dimensions? or is it just a quicker way of creating two crossfilter dimensions.
Thank you for the help!`
You can get the ordinal values with :
nameDimension.top(Infinity).map(function(d) {return d.Name}))
which returns ["Mike", "John", "Firen"] , then use it for the ordinal domain.
But it's not necessary, it's calculated automatically :
.x(d3.scale.ordinal())
.xUnits(dc.units.ordinal)
For colors, you can use :
dc.lineChart(lineChart1).group(mark1Group,"Mark 1").colors("#FF0000")
Here is a fiddle with those modifications : http://jsfiddle.net/1exo25u9/
Related
Sorry for this silly question, but I am lost and hope any other expert can help me.
I need to draw a bar chart, but the x axis is NOT time series, it is discrete values.
var ndx = crossfilter( self.getStatus( contracts ));
var skuDim = ndx.dimension( function(d){
return d.sku;
});
var skuDimCount = skuDim.group().reduceCount();
var chartLineContractSku= dc.barChart("#chart-line-contract-sku");
chartLineContractSku
.width(500)
.height(200)
.dimension(skuDim)
.group(skuDimCount)
.x(d3.scale.linear().domain(skus))
.legend(dc.legend());
the skus is:
array of sku:
["PAR-ND-SRX1-SPCNPC", "SVC-ND-M10i", "SVC-CP-SRX3400", "SVC-ND-SRX3400", "SVC-ND-SRX3-IOC", "SVC-CP-SRX3-IOC", "SVC-CP-SRX3-NPC", "SVC-3-ND-SRX3-IOC", "SVC-CP-SRX3-SPC", "SVC-ND-SRX3-SPC"]
which is used to group dimension the input data.
But the output graph is always empty.
Can anyone tell me how to fix this? And how to generate the barChart with discrete value? Also, another question is how to make the label vertical? as we have quite a lot skus.
Thanks
Gordon is correct in saying that you should use ordinal scale to get your desired result. Replace your d3.scale.linear code with
x(d3.scale.ordinal().domain(skus))
Look at this as an example
http://bost.ocks.org/mike/bar/3/
I am using NVD3.js multiChart to show multiple lines and bars in the chart. All is working fine, but the x-axis labels is aligned only to the line points, not bars. I want to correctly align labels directly below the bars as it should. But I get this:
With red lines I marked where the labels should be.
I made jsFiddle: http://jsfiddle.net/n2hfN/
Thanks!
As #Miichi mentioned, this is a bug in nvd3...
I'm surprised that they have a TODO to "figure out why the value appears to be shifted" because it's pretty obvious... The bars use an ordinal scale with .rangeBands() and the line uses a linear scale, and the two scales are never made to relate to one another, except in that they share the same endpoints.
One solution would be to take the ordinal scale from the bars, and simply adjust it by half of the bar width to make the line's x-scale. That would put the line points in the center of the bars. I imagine that something similar is done in the nv.models.linePlusBarChart that #LarsKotthoff mentioned.
Basically, your line's x-scale would look something like this:
var xScaleLine = function(d) {
var offset = xScaleBars.rangeBand() / 2;
return xScaleBars(d) + offset;
};
...where xScaleBars is the x-scale used for the bar portion of the chart.
By combing through the source code for nvd3, it seems that this scale is accessible as chart.bars1.scale().
Maybe someday the authors of nvd3 will decide that their kludge of a library deserves some documentation. For now, I can show you the kind of thing that would solve the problem, by making a custom chart, and showing how the two scales would relate.
First, I'll use your data, but separate the line and bar data into two arrays:
var barData = [
{"x":0,"y":6500},
{"x":1,"y":8600},
{"x":2,"y":17200},
{"x":3,"y":15597},
{"x":4,"y":8600},
{"x":5,"y":814}
];
var lineData = [
{"x":0,"y":2},
{"x":1,"y":2},
{"x":2,"y":4},
{"x":3,"y":6},
{"x":4,"y":2},
{"x":5,"y":5}
];
Then set up the scales for the bars. For the x-scale, I'll use an ordinal scale and rangeRoundBands with the default group spacing for nvd3's multiBar which is 0.1. For the y-scale I'll use a regular linear scale, using .nice() so that the scale doesn't end on an awkward value as it does by default in nvd3. Having some space above the largest value gives you some context, which is "nice" to have when trying to interpret a chart.
var xScaleBars = d3.scale.ordinal()
.domain(d3.range(barData.length))
.rangeRoundBands([0, w], 0.1);
var yScaleBars = d3.scale.linear()
.domain([0, d3.max(barData, function(d) {return d.y;})])
.range([h, 0])
.nice(10);
Now here's the important part. For the line's x-scale, don't make a separate scale, but just make it a function of the bars' x-scale:
var xScaleLine = function(d) {
var offset = xScaleBars.rangeBand() / 2;
return xScaleBars(d) + offset;
};
Here's the complete example as a JSBin. I've tried to document the major sections with comments so it's easy to follow the overall logic of it. If you can figure out from the nvd3 source code exactly what each of the elements of the multiChart are called and how to set the individual scales of the constituent parts, then you might be able to just plug in the new scale.
My feeling on it is that you need to have a pretty good handle on how d3 works to do anything useful with nvd3, and if you want to customize it, you're probably better off just rolling your own chart. That way you have complete knowledge and control of what the element classes and variable names of the parts of your chart are, and can do whatever you want with them. If nvd3 ever gets proper documentation, maybe this will become a simple fix. Good luck, and I hope this at least helps you get started.
I'm trying to visualize 2 series but when I visualize them together, the dates don't go in sequential order anymore.
Here is the fiddle: http://jsfiddle.net/hohenheim/6R7mu/21/ Notice the weird x-axis.
Is there a way to fix the x axis on nvd3?
The data looks like this:
data1 = [{
"date": 1396828800,
"impressions": 49145385
}, {
"date": 1396915200,
"impressions": 46704447
} ....
The NVD3 "multiBarChart" uses an ordinal (category) scale, so it will only display the x-values you give it, in the order in which they are added to the scale. Because your two series only partially overlap on the x axis that's causing problems.
Unlike other NVD3 chart types, the multiBarChart doesn't give you the option of setting your own scale -- it needs to use an ordinal scale in order to generate even widths for the bars. However, you can set the x domain (the list of categories to use for each bar), by calling chart.xDomain(arrayOfXValues).
The array will need to be an ordered array of Date values that spans your data. In order to generate it, you'll need the d3 time intervals range functions. You might also need the d3.extent function to find your max and min values.
I followed D3 multi-series line chart example and could successfully draw it. Now I need to add a line which is mean or average of all the lines drawn in the chart. Consider following points are plotted on chart to draw two lines:
Line 1 : [x:10, y:10], [x:20, y:20], [x:30, y:10]
Line 2 : [x:10, y:10], [x:20, y:18], [x:30, y:15]
Then mean line would be :
Mean : [x:10, y:(10+10)/2], [x:20,y : (20+18)/2], [x:30,y:(10+15)/2]
Is there a direcy way of drawing this mean line in D3 or i'll have to compute the mean values for y and draw a new line?
Hope this makes it clear.
Thanks in advance.
You can use d3.mean to compute this. The easiest way is to simply add another element to cities:
cities.push({
name: "mean",
values: data.map(function(d) {
return {date: d.date,
temperature: d3.mean(color.domain().map(function(e) { return +d[e]; } ))};
})
});
Full example here.
I'm trying to make an chart using the default line plus bar chart, but I want to use two or more streams in the bars, is it possible?
Currently, when I try to do this, I got some trouble with the effects of the chart, and so I can't show properly the hover balloon of the bars, he always display the data of just one of the streams. But the main problem is the dates of x axis, displaying 1970's dates, when I remove the second stream of bars, the dates display well:
Anyone already tried to do this kind of chart successfully?
EDIT
Adding Fiddles:
Fiddle with two columns stream and messy dates
Fiddle with just one column stream and ok dates
I'm calling this kind of graph:
linePlusBarChart()
The problem with the dates is that your data contains timestamps (i.e. in seconds), but Javascript expects milliseconds. This is easily fixed by multiplying the values by 1000:
series.values = series.values.map(function (d) {
return {
x: d[0]*1000,
y: d[1]
}
});
The tooltip problem is actually a bug in NVD3 -- it's not meant to be used this way. The problem boils down to the mouseover handler assuming that the first item of the data is representative of what you want. You can fix this for your case by selecting the item by data point number modulo 2 (because there're two bars):
.on('mouseover', function(d,i) {
d3.select(this).classed('hover', true);
dispatch.elementMouseover({
point: d,
series: data[i%2],
pos: [x(getX(d,i)), y(getY(d,i))],
pointIndex: i,
seriesIndex: i%2,
e: d3.event
});
})
This will only work for exactly two bar series though. Updated jsfiddle with the modified NVD3 code here.