Add text / label to each point / circle in nvd3 scatter plot? - d3.js

I've followed the nvd3 scatter plot example to create a scatter plot: http://nvd3.org/examples/scatter.html
What i'd like to do is display the "size" property (from the data) beneath each circle. I've been trying various combinations of trying to selectAll of the "g.nv-group" elements and then appending "text", but nothing is working.
Any thoughts?

If the data has a label property and
chart.showLabels(true)
then this discussion on a closed (not merged) PR suggests it should work. Works on lineCharts.

I tweaked code from the link from the comment above, in my case, this worked
d3.selectAll(".nv-group path")[0].forEach(function(d){
var tf = d3.select(d).attr("transform")
t = d3.transform(tf).translate;
t[0] = t[0] +10;//moving the translate x by 5 pixel.
console.log(d3.select(d).data()[0])//data associated with the point
d3.select(d.parentNode)
.append("text")
.attr("class", "label")
.text("data: "+ d3.select(d).data()[0][0].size)//putting data
.attr("transform", "translate("+t[0]+","+t[1]+")");
});

Related

2 lines LineGraph in dc-js

I might have missed something obvious but how do you plot a non-stacked line chart in dc-js ?
I have used the example jsFiddle as a base to try and add a second group to the lineChart definition but to no avail here : https://jsfiddle.net/chapo/pcn7mot5/
I defined a second group as :
speedSumGroup2 = runDimension.group().reduceSum(function(d) {return d.Speed * d.Run / 500;});
How do I plot it along with speedSumGroup ?
The stacked chart adds each line to the previous.
If the lines should be independent, the series chart is the way to go.

Rendering in the background of a dc.js chart with renderlet

I use dc.js for showing the results of multiple classification algorithms. More specifically, I want to show a precision recall chart (each point corresponds to a result of a classification system).
I already used a dc.js scatter chart for this which works fine.
Additionally I would like to have a d3 contour in the background of the chart which shows the F-measure.
This is already implemented. The only issue is that the contour part is in the foreground and not in the background of the chart.
Please have a look at the jsfiddle for a full example.
Two questions are still open for me because I'm not a dc.js or d3 expert:
Is there a way to put the contour in the background or the symbols(cycles) of the scatter chart in the foreground (I already tried it with the help of this stackoverflow question but with no success)
I used the 'g.brush' selector to get the area of the inner chart. This works fine as long as the brushing is turned on. Is the selector a good way to go or are there better alternatives (which may also work if brushing is switched off).
In my example I put the contour part in the upper left corner to see if it works but I also provide the code (currently uncommented) to increase the width and height of the contour to the correct size.
chart
.on('renderlet', function (chart) {
var innerChart = chart.select('g.brush');
var width = 300, height=300;
//getting the correct width, height
//var innerChartBoundingRect = innerChart.node().getBoundingClientRect();
//var width = innerChartBoundingRect.width, height=innerChartBoundingRect.height;
[contours, color] = generateFmeasureContours(width,height, 1);
innerChart
.selectAll("path")
.data(contours)
.enter()
.append("path")
.attr("d", d3.geoPath())
.attr("fill", d => color(d.value));
var symbols = chart.chartBodyG().selectAll('path.symbol');
symbols.moveToFront();
});
jsfiddle
Putting something in the background is a general purpose SVG skill.
SVG renders everything in the order it is declared, from back to front, so the key is to put your content syntactically before everything else in the chart.
I recommend encapsulating it in an svg <g> element, and to get the order right you can use d3-selection's insert method and the :first-child CSS selector instead of append:
.on('pretransition', function (chart) {
// add contour layer to back (beginning of svg) only if it doesn't exist
var contourLayer = chart.g().selectAll('g.contour-layer').data([0]);
contourLayer = contourLayer
.enter().insert('g', ':first-child')
.attr('class', 'contour-layer')
.attr('transform', 'translate(' + [chart.margins().left,chart.margins().top].join(',') + ')')
.merge(contourLayer);
A few more points on this implementation:
use dc's pretransition event because it happens immediately after rendering and redrawing (whereas renderlet waits for transitions to complete)
the pattern .data([0]).enter() adds the element only if it doesn't exist. (It binds a 1-element array; it doesn't matter what that element is.) This matters because the event handler will get called on every redraw and we don't want to keep adding layers.
we give our layer the distinct class name contour-layer so that we can identify it, and so the add-once pattern works
contourLayer = contourLayer.enter().insert(...)...merge(contourLayer) is another common D3 pattern to insert stuff and merge it back into the selection so that we treat insertion and modification the same later on. This would probably be simpler with the newer selection.join method but tbh I haven't tried that yet.
(I think there may also have been some improvements in ordering that might be easier than insert, but again, I'm going with what I know works.)
finally, we fetch the upper-left offset from the margin mixin
Next, we can retrieve the width and height of the actual chart body using
(sigh, undocumented) methods from dc.marginMixin:
var width = chart.effectiveWidth(), height = chart.effectiveHeight();
And we don't need to move dots to front or any of that; the rest of your code is as before except we use this new layer instead of drawing to the brushing layer:
contourLayer
.selectAll("path")
.data(contours)
.enter()
.append("path")
.attr("d", d3.geoPath())
.attr("fill", d => color(d.value));
Fork of your fiddle.
Again, if you'd like to collaborate on getting a contour example into dc.js, that would be awesome!

nvd3's x-axis broken due to one line change?

In this live code link,
http://nvd3.org/livecode/index.html#codemirrorNav
if you add chart.yRange([0, 300]) for inverting the y-axis, the x-axis moves up
and sticks to the top(near the legend).
Any possible fix?
PS: The problem is with most of the charts on that page but 'Cumulative line chart' is closest to my use case.
The position of the x axis is hardcoded to y.range()[0] in the NVD3 source, but you can adjust this after the chart has been drawn. In your particular case, add the following code after .call(chart):
d3.select('.nv-x.nv-axis')
.attr('transform', 'translate(0,' + chart.yAxis.range()[1] + ')');

Add a custom tick / marker for d3.time.scale() in a dc.js seriesChart

I would like to add a marker for a specific date for a date axis. Please see the line chart below.
My xAxis is drawn by this function, where dateMin and dateMax can be set by the user through the front end (or a brush, etc.).
d3.time.scale.utc().domain([dateMin,dateMax]);
This means the tickValues are calculated automatically.
Now, there is a certain fixed date for our data where there is a cutoff. For example, we may have consolidated figures up to Jan. 31st 2014, and then projected data from February 1st 2014 onwards.
What I need to do is make it visually clear at what date the cutoff point is. I have manually drawn a red vertical line at the date into the JPG below. But how do I do this programatically with d3?
One caveat is that the user might choose a date range (using the brush, etc.) which does not include the cutoff date (say, Jan 1st 2014 to Jan 20th, 2014). In this case, no line should be drawn.
If possible, it would be even better if the actual lines of the line chart would look different from the cutoff date onwards. They could be dotted instead of solid, or their colours could be less saturated (.brighter ?), to make visually clear that the underlying data is not consolidated yet.
Thanks for any hints you can give me.
Sorry I can't post images to StackOverflow yet, hence I uploaded the example here:
Trying out code from the answers
Using the code below, the line and label get drawn, but not at the given x value (cutoffDate), but too "early" on the time scale, approximately on the evening of 2014-01-29.
var cutoffDate = new Date("2014-02-01T00:00:00Z");
seriesChart.svg().append("svg:line")
.attr("x1", xScale(cutoffDate))
.attr("x2", xScale(cutoffDate))
.attr("y1", yScale.range()[1])
.attr("y2", yScale.range()[0])
.style("stroke", "rgb(225,0,0)")
.style("stroke-width", "1");
seriesChart.svg()
.append("text")
.attr("text-anchor", "start")
.attr("x", xScale(cutoffDate))
.attr("y", 80)
.text("Projected data");
See the result here:
http://i.imgur.com/0PXKFup.jpg
In my original question, I didn't mention I am using seriesChart from dc.js:
seriesChart API docs
I suppose this does something with the xScale when it composes the seriesChart so setting a value on the xScale later on will result in a shifted display. Will investigate further.
Update: x position fixed
The correct way to append svg elements to a dc.js chart is not to use
chart.svg().append()
but
chart.chartBodyG().append()
This fixes the position offset for custom elements added to the chart. Using this in combination with Lars' answer works.
This would be difficult to achieve with one axis, but easy with separate axes. First, for the dividing line, you can use code like this:
svg.append("line")
.attr("x1", xScale(cutoffDate))
.attr("x2", xScale(cutoffDate))
.attr("y1", yScale.range()[0])
.attr("y2", yScale.range()[1]);
svg.append("text").attr("x", xScale(cutoffDate) + 10).attr("y", yCoord)
.text("projected");
To have different styles, use two different axes:
var xScale1 = d3.time.scale().domain([..., cutoffDate]).range([0, 100]),
xScale2 = d3.time.scale().domain([cutoffDate, ...]).range([100, 200]);
svg.append("g").attr("class", "before")
.call(d3.svg.axis().scale(xScale1));
svg.append("g").attr("class", "after")
.attr("transform", "translate(" + xScale1.range()[1] + ",0)")
.call(d3.svg.axis().scale(xScale2));
Once appended, you can style the axes using the classes or by selecting the individual DOM elements. This means you end up with two scales -- to make using them for computing coordinates easier, you could wrap them:
var xScale = function(x) { return x < cutoffDate ? xScale1(x) : xScale2(x); };
The exact best way to implement this will depend on your specific application, but the above should give you a rough guide how to do it.

d3.js: Align text labels between ticks on the axis

Is there an easy way to align text labels between ticks?
Here is my time axis with labels above the ticks:
I would like to place these labels like here:
I ended up with one of the Lars Kotthoff's advices.
Every time when I call(axis) I also adjust text labels.
Here is simplified code:
function renderAxis() {
axisContainer
.transition().duration(300)
.call(axis) // draw the standart d3 axis
.call(adjustTextLabels); // adjusts text labels on the axis
}
function adjustTextLabels(selection) {
selection.selectAll('.major text')
.attr('transform', 'translate(' + daysToPixels(1) / 2 + ',0)');
}
// calculate the width of the days in the timeScale
function daysToPixels(days, timeScale) {
var d1 = new Date();
timeScale || (timeScale = Global.timeScale);
return timeScale(d3.time.day.offset(d1, days)) - timeScale(d1);
}
Update:
BTW, here is a calendar demo with I ended up: http://bl.ocks.org/oluckyman/6199145
There is no easy (i.e. built-in) way of doing this, but you can still achieve it. There are a few options. The most straightforward one is probably to use the tickFormat function to specify a format with a suitable number of spaces in front/after the numbers. This would need to be hand-tuned for each application though.
Alternatively, you could select the label elements after they have been drawn and add a suitable transform attribute that shifts them accordingly. Again, this would have to be hand-tuned.
Your third option is to have two different axes, one for the ticks and one for the labels. The idea is that the axis that provides the ticks has no labels and the other one no ticks. You would need to set the tick values appropriately, but at least you wouldn't have to guess the right offset.
You might want to consider using D3FC, which has a drop-in replacement for the D3 axis component that supports this feature.
Here's an example which substitutes the D3 axis d3.axisBottom, for the D3FC equivalent fc.axisBottom:
const axis = fc.axisBottom(linear)
.tickCenterLabel(true);
The tickCenterLabel centres the axis labels as requested.
Here's what the axis looks like with tickCenterLabel = false:
And here with the tickCenterLabel = true:
Full disclosure - I'm a maintainer and contributor to D3FC
You can do this by using axis.tickSize(major[[,minor],end]) and .tickSubdivide(). Your ticks are set to line up with the major ticks, but if you set the height of these ticks to 0, and set some height for minor ticks, and specify that there is one minor tick between each pair of major ticks, you will end up with tick labels between your ticks. Your code would look like this:
var myAxis = d3.svg.axis()
.ticks(15)
.tickSubdivide(1)
.tickSize(0, 6, 0);
Note that you need to explicitly set an end size. If you only provide two numbers, they will be interpreted as major and end and minor will default to 0.
Here's a fiddle.
I often do this by stacking multiple axes, each with a custom .tickFormat().
If I'm placing labels in between dates, I'll often do something like this:
#timeDaysAxisLabels = d3.svg.axis()
.scale(#timescale)
.orient('bottom')
.ticks(d3.time.hour.utc, 12) # I want ticks at noon, easiest to just get them ever 12 hours
.tickFormat((d) =>
# only draw labels at noon, between the date boundaries
if d.getUTCHours() == 12
# draw the label!
formatter = d3.time.format.utc('%a %d %b') # "Mon 12 Apr"
return formatter(d)
else
# not noon, don't draw anything
return null)
.tickSize(0)
.tickPadding(30)
I'll also create a separate axis with no labels at all, and a non-zero .tickSize() to actually draw ticks, but this block above positions date labels in the center of the "column".
Already a few good replies but just to add one more. Note the use of text-anchor.
Same idea: After your call, select the text, reposition.
.call(xAxis)
.selectAll(".tick text")
.style("text-anchor", "start")
.attr("x", axisTextAdjust)
svg.append("g")
.attr("class", "axis axis-years")
.attr("transform", "translate(0," + (height + 1) + ")")
.call(xAxis)
.selectAll("text")
.attr("x", "-1.8em")
.attr("y", ".00em")
.attr("transform", function (d) {
return "rotate(-90)"});

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