I am a novice while working on d3.js.
I wanted to know how can we Animate some data (eg. Change colors) with respect to time.
eg. Let's say, in Monitoring app, I am projecting cluster data over US Map. Projection is done by drawing a circle and filling it by RED, GREEN or YELLOW color depending on it's status.
When we start monitoring, ideally all circles will be filled with "GREEN" color and then over time color can change to "YELLOW" or "RED" depending on how cluster is behaving.
So if I need to play these color changes over time in some time window, how can it be done ?
If you can point me to any of the similar examples , that will help too ?
Thanks
Take a look at http://mbostock.github.com/d3/tutorial/bar-2.html. Basically you'll need a redraw function that you'll call whenever you want to update your chart. (Note: there is nothing special about the name of this function, you can call it whatever you want.)
You can use setInterval to create a basic timer, this is the rate that your chart will be updated.
setInterval(function() {
redraw(); // call the function you created to update the chart
}, 1500);
Then you define redraw to update the chart data. This is a redraw function for a bar chart, but yours would be similar. You would just be adjusting the color based on the data instead of the y position and height.
function redraw() {
// Update…
chart.selectAll("rect")
.data(data)
.transition()
.duration(1000)
.attr("y", function(d) { return h - y(d.value) - .5; })
.attr("height", function(d) { return y(d.value); });
}
Note that this is a simplified version, I recommend reading the page that I linked above for a more complete example.
Related
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!
I'm using the scrollama javascript library to write a "scrollytelling" article that involves transitioning D3 graphs in and out of view as the user scrolls. It is mostly working, but the graphs pile up on top of each other if I scroll too quickly.
Here is a jsfiddle based on this example by the scrollama author. In my example, the colored dots should fade in one at a time. If you were to scroll quickly to the end, the intermittent dots should not show up. The following snippets show how I've set up the transitions:
I define some functions that create my "graphs", and then call them.
var makeCircle0 = function(){
g.append("circle")
.attr("cx", 50)
.attr("cy", 100)
.attr("r", 20)
.attr("fill", "red")
.attr("class", "redcircle")
g.selectAll(".redcircle")
.attr("opacity", 0)
}
makeCircle0();
// Do this for makeCircle1, 2, and 3, also.
Then, I make functions to handle the transitions. This one says to make the red circle fade in and put the other circles at 0 opacity. I do this for all the circles/stages.
var showCircle0 = function(){
g.selectAll(".redcircle")
.transition()
.duration(1000)
.attr("opacity", 1)
g.selectAll(".yellowcircle").attr("opacity", 0)
g.selectAll(".greencircle").attr("opacity", 0)
g.selectAll(".bluecircle").attr("opacity", 0)
}
This section creates an array of my transition functions so that I can call them at specific steps in the page as you scroll. This is similar to how Jim Vallandingham handled his scroller.
var activateFunctions = [];
activateFunctions[0] = showCircle0;
activateFunctions[1] = showCircle1;
activateFunctions[2] = showCircle2;
activateFunctions[3] = showCircle3;
Finally, this calls the desired function at the right step in the page. Which it does... but not without halting the other transitions that got triggered in a previous step, resulting in multiple dots showing up at various stages.
function handleStepEnter(response) {
step.classed('is-active', function (d, i) {
return i === response.index;
})
figure.call(activateFunctions[response.index])
}
How can I prevent this?
If you need to interrupt a transition, d3-transition has a method for that:
selection.interrupt();
This will cancel a transition on an selection. If using named transitions you can specify a name by providing interrupt with one argument indicating the name of the transition to cancel.
If this is a generic version of your function to show an element:
function show() {
selectionToHide.attr("opacity",0);
selectionToShow.transition()
.attr("opacity",1);
}
Without using selection.interrupt you set the opacity to zero, and then the next tick of any transition in progress continues to update the opacity and finishes carrying out the transition. By adding interrupt we avoid that. Here's an updated fiddle.
However, there is another solution - we can apply another transition on the elements that we want to not show. To do so we just replace the transition with a new one:
function show() {
selectionToHide.transition()
.attr("opacity",0);
selectionToShow.transition()
.attr("opacity",1);
}
This will replace existing unnamed transitions (as yours are not named) and fade out elements, rather than simply hiding them all at once. Here's a fiddle of that. Of course if you have many elements this can be refined as to only apply a transition on any elements that are transitioning (not those that are already hidden) to reduce the amount of active transitions.
I haven't touched the scrolling, the circle that is shown should have its index match the displayed number, but it seems the number doesn't always match the scroll position, but this is a separate issue
In Mike Bostock's cubism demo (http://bost.ocks.org/mike/cubism/intro/demo-stocks.html), there is a cursor which displays the values of all horizon charts on display. Furthermore, the cursor text shows the time axis point in time. As the cursor text obscures an axis label, the label fades.
I am working on a similar display with d3.js (but not cubism). I have all working except that fade portion. I have searched through the CSS in the developer's window, searched the source code (as best I could), but I don't understand what manner of magic is being used to accomplish this feat. I've even looked through SO "axis label transition" questions, but I have failed to connect the dots on xaxis label transitions.
How does that fade in/out when obscured by text happen?
UPDATE:
I think I located the event script area where this happens - its just a little over my head at the moment - can anyone help me decipher what this event listener is doing? Specifically, in the second g.selectAll in the else clause below - what data (d) is being used here? What is causing this event to fire?
This is the coolest part of the display (outside of the horizon charts), I would love to figure this out ...
context.on("focus.axis-" + id, function(i) {
if (tick) {
if (i == null) {
tick.style("display", "none");
g.selectAll("text").style("fill-opacity", null);
} else {
tick.style("display", null).attr("x", i).text(format(scale.invert(i)));
var dx = tick.node().getComputedTextLength() + 6;
g.selectAll("text").style("fill-opacity", function(d) { return Math.abs(scale(d) - i) < dx ? 0 : 1; });
}
}
});
I used this as reference to accomplish the same effect.
I'm not sure what the context variable is or how the id's are set or what the tick flag references but what I did was simply update the opacity of the ticks according to their proximity to the mouse. With this, the vertical tick fades as well as the label text.
svg.selectAll('.x.axis .tick').style('opacity', function (d) {
return Math.min(1, (Math.round(Math.abs(d3.mouse(svg.node())[0] - x(d))) - 10) / 15.0);
});
This way, the opacity is set to 0 if it's within 10 pixels, and fades from 1-0 between 10 and 25. Above 25, the opacity would be set to an increasingly large number, so I clamp it to 1.0 using the Math.min function.
My labels are slightly rotated, so I also added an offset not shown inside the formula above (a +3 after [0]) just to make it look a bit nicer. A year late to answer your only question, but hey it's a nice effect.
same answer as Kevin Branigan's post, but using the d3 scale to calculate the opacity value.
var tickFadeScale = d3.scale.linear().domain([10,15]).range([0,1]).clamp(true);
svg.selectAll('.x.axis .tick').style('opacity', function (d) {
return tickFadeScale(Math.abs(d3.mouse(svg.node())[0] - x(d)));
}
I have a problem that I haven't been able to solve for a number of weeks. I'm working on a modified version of this example: http://bl.ocks.org/mbostock/1667367 I've defined the brush initially so it has a brush extent between 0.5 and 0.8.
var brush = d3.svg.brush()
.x(x2)
.extent([0.5, 0.8])
.on("brush", brushed);
The brush selection shows up (on the context graph) in the correct location, but the initial view of the focus area is still set to the extent of the entire data set (and not to the clipping area of the brush). I've read that defining the brush doesn't automatically force a redraw of the area, but I can't seem to figure out how to make the view of the focus area automatically scale to the brush extents. Can someone please provide some input on this?
Update 1
I currently have a function called Brushed which does the following:
function brushed() {
x.domain(brush.empty() ? x2.domain() : brush.extent());
focus.select("path").attr("d", Light_area);
focus.select(".x.axis").call(xAxis);
Light_line_overlay.select("path").attr("d", Light_area);
rules.select(".y.grid").call(make_x_axis_light()
.tickSize(-height, 0, 0)
.tickFormat("")
);
var xx0=brush.x()(brush.extent()[0]);
var xx1=brush.x()(brush.extent()[1]);
brushfill.attr("x", xx0);
brushfill.attr("width", xx1-xx0);
}
It's slightly different from the example... because I've been modifying it to do different things from the base example. However, the first comment suggests that I should just call this brushed function after declaring the brush (see first post). However, calling this function doesn't do anything (or at least, it doesn't update the focus area to the extents of the brush). Do you have any suggestions?
I apologize for answering this two years late but I just ran in to the same situation and this was the only resource I found on the topic. I was able to figure it out, so hopefully this will help anybody else who stumbles upon it.
The code in the original question was almost all the way there, it just didn't have the right scaling on the extent initialization.
The data I'm using is an array of objects with a ts key (which is epoch milliseconds) that I use for my x values.
// These are needed for the brush construction to know how to scale
x2.domain(x.domain());
y2.domain(y.domain());
// Pick out the ~50% and ~80% marks from the data
var N = data.length;
var cx0 = new Date(data[Math.floor(N*0.50)].ts);
var cx1 = new Date(data[Math.floor(N*0.80)].ts);
// Construct with that extent, which will leave the
// context box started in the correct position.
var brush = d3.svg.brush()
.x(x2)
.extent([cx0, cx1])
.on("brush", brushed)
;
// This is just the original brushed example
function brushed() {
x.domain(brush.empty() ? x2.domain() : brush.extent());
focus.select(".area").attr("d", line);
focus.select(".x.axis").call(xAxis);
}
...
var focus = svg.append("g")
.attr("class", "focus")
.attr("transform",
"translate(" + margin.left + "," + margin.top + ")")
;
// Now that focus is defined we can manually update it
brushed();
I actually kept the call to brushed at the very end of the setup, just to keep things pretty, but the point here was just to illustrate that once focus is defined you can call brushed to do whatever updates you want there.
Ultimately it seems your main issue was getting the right type for the extent. Using [0.5, 0.8] worked on initialization, but if you check whenever brushed is called from actually sliding the focus around with the mouse, brush.extent() will be [Date(), Date()]. And that makes sense, since we're passing that extent to x.domain. So this sets up all the scaling before initializing the brush, so that the initialization extent can be a Date, then everything else is gravy.
You need to perform actions similar to the ones of the brushed function whenever your brush extent is changed programmatically. Resize the x.domain, refresh the view.
function brushed() {
x.domain(brush.empty() ? x2.domain() : brush.extent());
focus.select("path").attr("d", area);
focus.select(".x.axis").call(xAxis);
}
If that doesn't solve your problem, consider providing some code example.
I'm having trouble understanding using D3 events and dispatch functions. I have a chart example that I've been working on called: "Vertical Bar Charts With Legends."
Drawing the charts and the legends was easy enough but I'd like to add the ability to highlight each bar as I mouseover its correlating text legend, located to the right of the chart.
I've read through all of the event documentation and even looked at a number of examples, most of which are pretty complicated, but I seem to be missing something. Would anyone know how to best accomplish the text legend mouseover functionality that dispatches events to automatically change colors of the corresponding vertical bars?
This question is similar to the one you posted in the d3-js Google Group. Without duplicating what I wrote there, I would reiterate that you probably don't want d3.dispatch; that is intended for custom event abstractions (such as brushes and behaviors). It'll be simpler to use native events.
If you want your legend to change the color of the corresponding bar on mouseover, then breakdown the problem into steps:
Detect mouseover on the legend.
Select the corresponding bar.
Change the bar's fill color.
First, use selection.on to listen for "mouseover" events on the legend elements. Your listener function will be called when the mouse goes over a legend element, and will be called with two arguments: the data (d) and the index (i). You can use this information to select the corresponding bar via d3.select. Lastly, use selection.style to change the "fill" style with the new color.
If you're not sure how to select the corresponding bar on legend mouseover, there are typically several options. The most straightforward is to select by index, assuming that the number of legend elements and number of rect elements are the same, and they are in the same order. In that case, if a local variable rect contains the rect elements, you could say:
function mouseover(d, i) {
d3.select(rect[0][i]).style("fill", "red");
}
If you don't want to rely on index, another option is to scan for the matching bar based on identical data. This uses selection.filter:
function mouseover(d, i) {
rect.filter(function(p) { return d === p; }).style("fill", "red");
}
Yet another option is to give each rect a unique ID, and then select by id. For example, on initialization, you could say:
rect.attr("id", function(d, i) { return "rect-" + i; });
Then, you could select the rect by id on mouseover:
function mouseover(d, i) {
d3.select("#rect-" + i).style("fill", "red");
}
The above example is contrived since I used the index to generate the id attribute (in which case, it's simpler and faster to use the first technique of selecting by index). A more realistic example would be if your data had a name property; you could then use d.name to generate the id attribute, and likewise select by id. You could also select by other attributes or class, if you don't want to generate a unique id.
Mike's answer is great.
I used it come up with this for selecting a cell in a grid I was drawing:
.on('click', (d, i) ->
console.log("X:" + d.x, "Y:" + d.y) #displays the cell x y location
d3.select(this).style("fill", "red");
So when I am entering the data in I added the event listener and using d3.select(this).
See the code in context below:
vis.selectAll("rect")
.data(singleArray)
.enter().append("svg:rect")
.attr("stroke", "none")
.attr("fill", (d) ->
if d.lifeForm
return "green"
else
return "white")
.attr("x", (d) -> xs(d.x))
.attr("y", (d) -> ys(d.y))
.attr("width", cellWidth)
.attr("height", cellHeight)
.on('click', (d, i) ->
console.log("X:" + d.x, "Y:" + d.y)
d3.select(this).style("fill", "red");
return
)