I am making an interactive area chart using D3. While mousing over the area-chart, I'd like to have a dot rolling along the top of the chart, as in the following example:
http://hci.stanford.edu/jheer/files/zoo/ex/time/multiples.html
Once I get the mouse position (using d3.mouse), how do I translate these coordinates to the corresponding data? The x-axis is straightforward using the inverse of the x-scale (e.g. x.invert). However, I can't find the corresponding y-coordinate for my graph. Ideally I could "look up" the x-coordinate in my data and find the corresponding y-coordinate, but not sure how to do this with D3. Thanks!
It's actually relatively easy to create your own lookup table:
/* Create the lookup table */
var table = {};
data.forEach(function(d) {
table[d.x] = d.y;
});
This is a viable solution if you have enough data points, but it's likely that you will probably need to use some sort of rounding or interpolator to fill in the intermediate x-values. For instance, if there is a fixed spacing between your points, you can use a linear interpolator and do the following calculations to get the coordinates for your circle on mouseover:
var x = d3.mouse(this)[0];
var y;
if ( table[x] === undefined ) {
var lower = x - (x % SPACING);
var upper = lower + SPACING;
var between = d3.interpolateNumber(table[lower], table[upper]);
y = between( (x % SPACING) / SPACING );
} else {
y = table[x];
}
Here is the code in action: http://jsfiddle.net/Wexcode/KGxHF/
Here is another example of how you could do this from Mike Bostock: http://bl.ocks.org/3025699
mbostock (D3.js author) implement this here
svg.append("rect")
.attr("class", "overlay")
.attr("width", width)
.attr("height", height)
.on("mouseover", function() { focus.style("display", null); })
.on("mouseout", function() { focus.style("display", "none"); })
.on("mousemove", mousemove);
function mousemove() {
var x0 = x.invert(d3.mouse(this)[0]),
i = bisectDate(data, x0, 1),
d0 = data[i - 1],
d1 = data[i],
d = x0 - d0.date > d1.date - x0 ? d1 : d0;
focus.attr("transform", "translate(" + x(d.date) + "," + y(d.close) + ")");
focus.select("text").text(formatCurrency(d.close));
}
I use this code to see value X and Y of each point and draw a circle on my curve on mouse event :
exemple on jsFiddle here
Y_value is a global !
var Y_value;
i define my axes rage
x = d3.time.scale().range([0, w]);
y = d3.scale.linear().range([h, 0]);
i define the circle cursor
var circle = svg.append("circle")
.attr("r", 8)
.attr("cx", 0)
.attr("cy", 0)
.style({fill: '#fff', 'fill-opacity': .2, stroke: '#000', "stroke-width": '1px'})
.attr("opacity", 0);
i add a tooltip on my circle
var tooltip = circle.append("svg:title");
and i have my event code
mySensitiveArea.on("mousemove", function() {
var X_pixel = d3.mouse(this)[0],
X_date = x.invert(X_pixel);
var Y_pixel = y(Y_value);
var pathData = curve1.data()[0]; // recupere donnée de la courbe
pathData.forEach(function(element, index, array) {
if ((index+1 < array.length) && (array[index].date <= X_date) && (array[index+1].date >= X_date)) {
if (X_date-array[index].date < array[index+1].date-X_date) Y_value = array[index].val;
else Y_value = array[index+1].val;
}
});
circle.attr("opacity", 1)
.attr("cx", X_px)
.attr("cy", Math.round(y(Y_value)));
tooltip.text("X = " + (X_date) + "\nY = " + (Y_value));
});
Related
I just started learning javascript and d3.js by taking a couple of lynda.com courses. My objective is to create a function that takes an array of numbers and a cutoff and produces a plot like this one:
I was able to write javascript code that generates this:
Alas, I'm having troubles figuring out a way to tell d3.js that the area to the left of -opts.threshold should be read, the area in between -opts.threshold and opts.threshold blue, and the rest green.
This is my javascript code:
HTMLWidgets.widget({
name: 'IMposterior',
type: 'output',
factory: function(el, width, height) {
// TODO: define shared variables for this instance
return {
renderValue: function(opts) {
console.log("MME: ", opts.MME);
console.log("threshold: ", opts.threshold);
console.log("prob: ", opts.prob);
console.log("colors: ", opts.colors);
var margin = {left:50,right:50,top:40,bottom:0};
var xMax = opts.x.reduce(function(a, b) {
return Math.max(a, b);
});
var yMax = opts.y.reduce(function(a, b) {
return Math.max(a, b);
});
var xMin = opts.x.reduce(function(a, b) {
return Math.min(a, b);
});
var yMin = opts.y.reduce(function(a, b) {
return Math.min(a, b);
});
var y = d3.scaleLinear()
.domain([0,yMax])
.range([height,0]);
var x = d3.scaleLinear()
.domain([xMin,xMax])
.range([0,width]);
var yAxis = d3.axisLeft(y);
var xAxis = d3.axisBottom(x);
var area = d3.area()
.x(function(d,i){ return x(opts.x[i]) ;})
.y0(height)
.y1(function(d){ return y(d); });
var svg = d3.select(el).append('svg').attr("height","100%").attr("width","100%");
var chartGroup = svg.append("g").attr("transform","translate("+margin.left+","+margin.top+")");
chartGroup.append("path")
.attr("d", area(opts.y));
chartGroup.append("g")
.attr("class","axis x")
.attr("transform","translate(0,"+height+")")
.call(xAxis);
},
resize: function(width, height) {
// TODO: code to re-render the widget with a new size
}
};
}
});
In case this is helpful, I saved all my code on a public github repo.
There are two proposed solutions in this answer, using gradients or using multiple areas. I will propose an alternate solution: Use the area as a clip path for three rectangles that together cover the entire plot area.
Make rectangles by creating a data array that holds the left and right edges of each rectangle. Rectangle height and y attributes can be set to svg height and zero respectively when appending rectangles, and therefore do not need to be included in the array.
The first rectangle will have a left edge at xScale.range()[0], the last rectangle will have an right edge of xScale.range()[1]. Intermediate coordinates can be placed with xScale(1), xScale(-1) etc.
Such an array might look like (using your proposed configuration and x scale name):
var rects = [
[x.range()[0],x(-1)],
[x(-1),x(1)],
[x(1),x.range()[1]]
]
Then place them:
.enter()
.append("rect")
.attr("x", function(d) { return d[0]; })
.attr("width", function(d) { return d[1] - d[0]; })
.attr("y", 0)
.attr("height",height)
Don't forget to set a clip-path attribute for the rectangles:
.attr("clip-path","url(#areaID)"), and to set fill to three different colors.
Now all you have to do is set your area's fill and stroke to none, and append your area to a clip path with the specified id:
svg.append("clipPath)
.attr("id","area")
.append("path")
.attr( // area attributes
...
Here's the concept in action (albeit using v3, which shouldn't affect the rectangles or text paths.
Thanks to #andrew-reid suggestion, I was able to implement the solution that uses multiple areas.
HTMLWidgets.widget({
name: 'IMposterior',
type: 'output',
factory: function(el, width, height) {
// TODO: define shared variables for this instance
return {
renderValue: function(opts) {
console.log("MME: ", opts.MME);
console.log("threshold: ", opts.threshold);
console.log("prob: ", opts.prob);
console.log("colors: ", opts.colors);
console.log("data: ", opts.data);
var margin = {left:50,right:50,top:40,bottom:0};
xMax = d3.max(opts.data, function(d) { return d.x ; });
yMax = d3.max(opts.data, function(d) { return d.y ; });
xMin = d3.min(opts.data, function(d) { return d.x ; });
yMin = d3.min(opts.data, function(d) { return d.y ; });
var y = d3.scaleLinear()
.domain([0,yMax])
.range([height,0]);
var x = d3.scaleLinear()
.domain([xMin,xMax])
.range([0,width]);
var yAxis = d3.axisLeft(y);
var xAxis = d3.axisBottom(x);
var area = d3.area()
.x(function(d){ return x(d.x) ;})
.y0(height)
.y1(function(d){ return y(d.y); });
var svg = d3.select(el).append('svg').attr("height","100%").attr("width","100%");
var chartGroup = svg.append("g").attr("transform","translate("+margin.left+","+margin.top+")");
chartGroup.append("path")
.attr("d", area(opts.data.filter(function(d){ return d.x< -opts.MME ;})))
.style("fill", opts.colors[0]);
chartGroup.append("path")
.attr("d", area(opts.data.filter(function(d){ return d.x > opts.MME ;})))
.style("fill", opts.colors[2]);
if(opts.MME !==0){
chartGroup.append("path")
.attr("d", area(opts.data.filter(function(d){ return (d.x < opts.MME & d.x > -opts.MME) ;})))
.style("fill", opts.colors[1]);
}
chartGroup.append("g")
.attr("class","axis x")
.attr("transform","translate(0,"+height+")")
.call(xAxis);
},
resize: function(width, height) {
// TODO: code to re-render the widget with a new size
}
};
}
});
I am trying to create a parallel coordinates with my own code, so that i can learn d3.js very well. Now i am stuck in a situation. I have two axis with some data in it
and i want to connect the data with a line. I tried of getting the position of the two data in the axes but its not working for me and its got complicated
Is there any way to connect the axes like this?
The jsfiddle link is commented below. Please find it
Thanks for the help
Appending an svg:line between those ticks is the way to go but the hard part is finding the proper positioning within the overall SVG document. Since things are being transitioned twice (once for the axis g and once for the tick g), you have two options, sum up all the positions by using d3.tranform on the elements, or use something like getBoundingClientRect on the node.
In the below code I've chosen the later. This quick function will take the text value of any two ticks and draw a line. Note, those text values have to be unique:
function addLine(t1, t2){
var ticks = {};
d3.selectAll('.tick text').each(function(d) {
ticks[d3.select(this).text()] = this;
});
var pos1 = ticks[t1].getBoundingClientRect();
var pos2 = ticks[t2].getBoundingClientRect();
svg.append('line')
.attr('x1', pos1.left)
.attr('y1', pos1.top + 5)
.attr('x2', pos2.left - 5)
.attr('y2', pos2.top + 5)
.style('stroke','black');
}
addLine('a', 'ab');
addLine('a', 'bb');
Full working example:
var w = 200;
var h = 400;
var padding = 100;
var x = ["a","b"];
var z = ["aa","ab","ba","bb"];
var svg = d3.select("body")
.append("svg")
.attr("width", w)
.attr("height", h);
for(var i=1;i<3;i++){
var yScale = d3.scale.linear()
.domain([0, i === 1 ? x.length : z.length])
.range([h - padding, padding]);
//Define Y axis
var yAxis = d3.svg.axis()
.scale(yScale)
.ticks(i === 1 ? x.length : z.length)
.orient("left")
.tickSize(1)
.tickFormat(function(d){
return i === 1 ? x[d] : z[d];
})
// .style("text-anchor", "middle");
//Create SVG element
svg.append("g")
.attr("class", "axis" + i)
.attr("transform", "translate("+(i*padding)+",0)")
.call(yAxis)
.attr("fill","red");
}
function addLine(t1, t2){
var ticks = {};
d3.selectAll('.tick text').each(function(d) {
ticks[d3.select(this).text()] = this;
});
var pos1 = ticks[t1].getBoundingClientRect();
var pos2 = ticks[t2].getBoundingClientRect();
svg.append('line')
.attr('x1', pos1.left)
.attr('y1', pos1.top + 5)
.attr('x2', pos2.left - 5)
.attr('y2', pos2.top + 5)
.style('stroke','black');
}
addLine('a', 'ab');
addLine('a', 'bb');
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
I am having an issue with d3.js when I try to zoom in and out on a graph. The zoom is very slow and laggy. I am trying to debug by using the profiling tool (Opera/Chrome). I was expecting my zoom callback function to be the limiting factor but it turns out there is a lot of idle time between each mousewheel scroll events.
Motus operandum: I start the profiling, then give a big sharp scroll on the mousewheel (5sec on the graph). The graph lags for several seconds(from 5sec to 8.5sec on the graph) then calls my zoom callback periodically (from 8.5 to 14sec on the graph). I checked the stack calls and all my zooming callbacks are executed in order, synchronously, which makes me think the are done executing during the idle time. I think the profiler does not record some of the system/browser calls and qualifies those as idle, so I tried using interruptions ( event.preventDefault() etc...) to make sure nothing was executed on zoomend. It improved a little bit the performance, but there is still a lot of idle time:
Can someone please help me figure out why there is so much idle time?
Here is my relevant code:
without interruption
d3Zoom = d3.behavior.zoom()
.x(element.self.xScale)
.y(element.self.yScale)
.scaleExtent([0.99, Infinity])
.on("zoom", semanticZoom)
.on("zoomend", updateSelection);
with interruption
var delayTimer=0;
d3Zoom = d3.behavior.zoom()
.x(xScale)
.y(yScale)
.scaleExtent([0.99, Infinity])
.on("zoom", semanticZoom)
.on("zoomstart", function () {
//prevent recalculating heavyCalculations too often
window.clearTimeout(delayTimer);
var evt = e ? e : window.event;
return cancelDefaultAction(evt);
})
.on("zoomend", function () {
// only start heavy calculations if user hasn't zoomed for 0.75sec
delayTimer = window.setTimeout(updateSelection, 750);
});
function cancelDefaultAction(e) {
var evt = e ? e : window.event;
if (evt.preventDefault) evt.preventDefault();
evt.returnValue = false;
return false;
}`
EDIT: Here is an example of working code. Both semanticZoom and update selection are more complex in my project than in this example but they involve custom AngularJS directives, d3 brushes, warped geometry, aggregation etc... I have cropped semanticZoom to just perform an enter/exit/update pattern based on a quadtree (it might behave funny in this the example, but it's just to show the kind of operations I do). UpdateSelection updates the visible data to an angular directive to perform calculations (various statistics etc...). I did not populate it here but it is not actually very intensive.
var size = 100;
var dataset = d3.range(10).map(function(d, idx) {
return {
x: d3.random.normal(size / 2, size / 4)(),
y: d3.random.normal(size / 2, size / 4)(),
uuid: idx
};
});
//
// Init Scales
//
var xScale = d3.scale.linear()
.domain([0, size])
.range([0, 100]);
var yScale = d3.scale.linear()
.domain([0, size])
.range([0, 100]);
//
// Init Axes
//
var xAxis = d3.svg.axis()
.scale(xScale)
.ticks(10)
.orient("bottom")
.tickSize(-size);
var yAxis = d3.svg.axis()
.scale(yScale)
.ticks(10)
.orient("left")
.tickSize(-size);
//
// Init Zoom
//
var d3Zoom = d3.behavior.zoom()
.x(xScale)
.y(yScale)
.scaleExtent([0.99, Infinity])
.on("zoom", semanticZoom)
.on("zoomend", updateSelection);
var quadtree = d3.geom.quadtree(dataset);
//------------------------ Callbacks --------------------------------
function semanticZoom() {
var s = 1;
var t = [0, 0];
if (d3.event) {
s = (d3.event.scale) ? d3.event.scale : 1;
t = (d3.event.translate) ? d3.event.translate : [0, 0];
}
// set zoom boundaries
// center of the zoom in svg coordinates
var center = [(size / 2 - t[0]) / s, (size / 2 - t[1]) / s];
// half size of the window in svg coordinates
var halfsize = size / (2 * s);
// top left corner in svg coordinates
var tl = [center[0] - halfsize, center[1] - halfsize];
// bottom right corner in svg coordinates
var br = [center[0] + halfsize, center[1] + halfsize];
/*
//
// Constrain zoom
//
if (!(tl[0] > -10 &&
tl[1] > -10 &&
br[0] < size + 10 &&
br[1] < size + 10)) {
// limit zoom-window corners
tl = [Math.max(0, tl[0]), Math.max(0, tl[1])];
br = [Math.min(size, br[0]), Math.min(size, br[1])];
// get restrained center
center = [(tl[0] + br[0]) / 2, (tl[1] + br[1]) / 2];
// scale center
t = [size / 2 - s * center[0], size / 2 - s * center[1]];
// update svg
svg.transition()
.duration(1)
.call( d3Zoom.translate(t).event );
}
*/
//
// Store zoom extent
//
d3Zoom.extent = [tl, br];
d3Zoom.scaleFactor = s;
d3Zoom.translation = t;
//
// Update some heavy duty stuff
// (create a quadtree, search that quadtree and update an attribute for the elements found)
//
// Prune non visible data
var displayedData = search(quadtree,
d3Zoom.extent[0][0], d3Zoom.extent[0][1],
d3Zoom.extent[1][0], d3Zoom.extent[1][1]);
redrawSubset(displayedData);
//
// Update axes
//
d3.select(".x.axis").call(xAxis);
d3.select(".y.axis").call(yAxis);
}
function redrawSubset(subset) {
//Attach new data
var elements = d3.select(".data_container")
.selectAll(".datum")
.data(subset, function(d) {
return d.uuid;
});
//enter
elements.enter()
.append("circle")
.attr("class", "datum")
.attr("r", 1)
.style("fill", "black");
//exit
elements.exit().remove();
//update
elements.attr("transform", ScaleData);
}
function updateSelection() {
// some not so heavy duty stuff
}
function ScaleData(d) {
return "translate(" + [xScale(d.x), yScale(d.y)] + ")";
}
//
// search quadtree
//
function search(qt, x0, y0, x3, y3) {
var pts = [];
qt.visit(function(node, x1, y1, x2, y2) {
var p = node.point;
if ((p) && (p.x >= x0) && (p.x <= x3) && (p.y >= y0) && (p.y <= y3)) {
pts.push(p);
}
return x1 >= x3 || y1 >= y3 || x2 < x0 || y2 < y0;
});
return pts;
}
//------------------------- DOM Manipulation -------------------------
var svg = d3.select("body").append("svg")
.attr("width", size)
.attr("height", size)
.append("g")
.attr("class", "data_container")
.call(d3Zoom);
svg.append("rect")
.attr("class", "overlay")
.attr("width", size)
.attr("height", size)
.style("fill", "none")
.style("pointer-events", "all");
var circle = svg.selectAll("circle")
.data(dataset, function(d) {
return d.uuid;
}).enter()
.append("circle")
.attr("r", 1)
.attr("class", "datum")
.attr("transform", ScaleData);
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
SemanticZoom and UpdateSelection have both been unit tested and run in times comparable to the profiler graphs above (50-100ms) for large datasets.
If you add a few zeros to the circle count and make the svg big enough to be useful, then the zoom slows down to what you describe. But it's hardly surprising since it has a bunch of work to do visiting the nodes in the quad tree and writing to the DOM to manage the svg components. I don't understand why you are transforming individual circles instead of grouping them and transforming the g. If you did that then you could just let the svg element clip the image and avoid all of the svg overheads which would free up 75% of your budget. If the only purpose of the quad tree is to figure out which nodes are visible then that would also be eliminated.
A key observation I guess is that this profile is markedly different from the pics you posted, judging by the profile of your pics, they seem to be all about the quad tree and the rest is idle time. It would be interesting to see your cpu and gpu loading during the profile.
You can eliminate the need for deleting and re-writing nodes by using a clip path, that way the only overhead is re-writing the transform attributes.
There was also a problem with your search. There is a much simpler way to do it that works fine and that is to use the #linear.invert(y) method of the scale.
Both these are addressed in the sample code below...
var size = 500;
var margin = {top: 30, right: 40, bottom: 30, left: 50},
width = 600 - margin.left - margin.right,
height = 200 - margin.top - margin.bottom;
d3.select("#clipButton").on("click", (function() {
var clipped = false, clipAttr = [null, "url(#clip)"],
value = ["clip", "brush"];
return function() {
circles
.attr("clip-path", clipAttr[(clipped = !clipped, +clipped)]);
this.value = value[+clipped];
}
})());
var dataset = d3.range(1000).map(function(d, idx) {
return {
x: d3.random.normal(100 / 2, 100 / 4)(),
y: d3.random.normal(100 / 2, 100 / 4)(),
uuid: idx
};
});
//
// Init Scales
//
var xScale = d3.scale.linear()
.domain([0, 100])
.range([0, width])
.nice(10);
var yScale = d3.scale.linear()
.domain([0, 100])
.range([height, 0])
.nice(10);
//
// Init Axes
//
var xAxis = d3.svg.axis()
.scale(xScale)
.ticks(10)
.orient("bottom")
.tickSize(-height);
var yAxis = d3.svg.axis()
.scale(yScale)
.ticks(10)
.orient("left")
.tickSize(-width);
//
// Init Zoom
//
var d3Zoom = d3.behavior.zoom()
.x(xScale)
.y(yScale)
.scaleExtent([0.99, Infinity])
.on("zoom", semanticZoom)
// .on("zoomend", updateSelection);
var Quadtree = d3.geom.quadtree()
.x(function(d){return d.x})
.y(function(d){return d.y});
quadtree = Quadtree(dataset);
//------------------------ Callbacks --------------------------------
function semanticZoom() {
var s = 1;
var t = [0, 0];
if (d3.event) {
s = (d3.event.scale) ? d3.event.scale : 1;
t = (d3.event.translate) ? d3.event.translate : [0, 0];
}
var tl = [xScale.invert(0), yScale.invert(height)];
var br = [xScale.invert(width), yScale.invert(0)];
//
// Store zoom extent
//
d3Zoom.extent = [tl, br];
d3Zoom.scaleFactor = s;
d3Zoom.translation = t;
//
// Update some heavy duty stuff
// (create a quadtree, search that quadtree and update an attribute for the elements found)
//
// Prune non visible data
var displayedData = search(quadtree, d3Zoom.extent);
markSubset(displayedData, circle);
updateSelection(circle);
//
// Update axes
//
d3.select(".x.axis").call(xAxis);
d3.select(".y.axis").call(yAxis);
};
function markSubset(data, nodes){
var marked = nodes.data(data, function(d){return d.uuid;});
marked.enter();
marked.classed("visible", true);
marked.exit().classed("visible", false);
}
function updateSelection(elements) {
// some not so heavy duty stuff
elements.attr("transform", ScaleData);
}
function ScaleData(d) {
return "translate(" + [xScale(d.x), yScale(d.y)] + ")";
}
//
// search quadtree
//
function search(qt, extent) {
var pts = [],
x0=extent[0][0], y0=extent[0][1],
x3=extent[1][0], y3=extent[1][1];
qt.visit(function(node, x1, y1, x2, y2) {
var p = node.point;
if ((p) && (p.x >= x0) && (p.x <= x3) && (p.y >= y0) && (p.y <= y3)) {
pts.push(p);
}
return x1 >= x3 || y1 >= y3 || x2 < x0 || y2 < y0;
});
return pts;
}
//------------------------- DOM Manipulation -------------------------
var svg = d3.select("body").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("class", "data_container")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")")
.call(d3Zoom),
plotSurface = svg.append("rect")
.attr("class", "overlay")
.attr("width", width)
.attr("height", height)
.style({"fill": "steelblue", opacity: 0.8})
.style("pointer-events", "all"),
gX = svg.append("g") // Add the X Axis
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis),
gY = svg.append("g")
.attr("class", "y axis")
.call(yAxis),
clipRect = svg.append("clipPath")
.attr("id", "clip")
.append("rect")
.attr("width", width)
.attr("height", height),
circles = svg.append("g")/*
.attr("clip-path", "url(#clip)")*/,
circle = circles.selectAll("circle")
.data(dataset, function(d) {
return d.uuid;
});
circle.enter()
.append("circle")
.attr("r", 3)
.attr("class", "datum")
.attr("transform", ScaleData);
semanticZoom();
svg {
outline: 1px solid red;
overflow: visible;
}
.axis path {
stroke: #000;
}
.axis line {
stroke: steelblue;
stroke-opacity: .5;
}
.axis path {
fill: none;
}
.axis text {
font-size: 8px;
}
.datum {
fill: #ccc;
}
.datum.visible {
fill: black;
}
#clipButton {
position: absolute;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
<input id="clipButton" type="button" value="clip">
I am trying to draw circles in a rectangular div. I have followed the advice from Question 13339615(the answer I used is also made available in this fiddle, and this works perfectly.
However, being completely new to d3, I cannot work out how to label the circles. What I would basically like to recreate is similar to the visualisation in this article.
I have tried the following modifications to the fiddle:
var bubbles = bubbleGroup.selectAll("circle")
.data(data)
.enter()
.append("circle")
.append("text").attr("dy", ".3em")
.style("text-anchor", "middle").text("test");
but this breaks the visualisation.
Following question 13615381 I have also tried things like:
var bubbles = bubbleGroup.selectAll("circle")
.data(data)
.enter()
.append("circle");
bubbleGroup.append("text")
.attr("dx", function(d){return -20})
.text(function(d){return "test"})
but the text does not display. I'm imaging the code should be some variation of these, but I cannot figure it out.
Thank you!
Fixed by putting the circle and text inside a g and adjusting the g css-transform.
JSFiddle
var bubbles = bubbleGroup.selectAll("g")
.data(data)
.enter().append("g").attr("class","gBubble");
bubbles.append("circle")
.on("mouseover",function(){
$(this).attr("cursor","pointer")
})
.on("click",function(){alert("clicked")});
bubbles.append("text").text(function(d){return d.name;}).style("opacity","1");
(function() {
//D3 program to fit circles of different sizes
//in a rectangle of fixed aspect ratio
//as tightly as reasonable.
//
//By Amelia Bellamy-Royds, in response to
//http://stackoverflow.com/questions/13339615/packing-different-sized-circles-into-rectangle-d3-js
//Based on Mike Bostock's
//"http://bl.ocks.org/mbostock/7882658" example:
//http://bl.ocks.org/mbostock/7882658
//parameters//
var N = 25; //number of nodes
var sortOrder = -1;
//>0 for ascending, <0 for descending, 0 for no sort
//create data array//
var data = [], i = N;
var randNorm = d3.random.normal(1,0.6);
while(i--) data.push({
"size": Math.max(randNorm(), 0.1) });
//circle area will be proportional to size
var dataMax = d3.max(data, function(d){return d.size;});
var totalSize = d3.sum(data, function(d){return d.size;});
//________________//
//Set up SVG and rectangle//
var svg = d3.select("svg");
var digits = /(\d*)/;
var margin = 50; //space in pixels from edges of SVG
var padding = 4; //space in pixels between circles
var svgStyles = window.getComputedStyle(svg.node());
var width = parseFloat(svgStyles["width"]) - 2*margin;
var height = parseFloat(svgStyles["height"]) - 2*margin;
var usableArea = Math.PI*
Math.pow( Math.min(width,height)/2 ,2)*0.667;
var scaleFactor = Math.sqrt(usableArea)/
Math.sqrt(totalSize)/Math.PI;
var rScale = d3.scale.sqrt()
//make radius proportional to square root of data r
.domain([0, dataMax]) //data range
.range([0, Math.sqrt(dataMax)*scaleFactor]);
//The rScale range will be adjusted as necessary
//during packing.
//The initial value is based on scaling such that the total
//area of the circles is 2/3 the area of the largest circle
//you can draw within the box.
/*
console.log("Dimensions: ", [height, width]);
console.log("area", width*height);
console.log("Usable area: ", usableArea);
console.log("TotalSize: ", totalSize);
console.log("Initial Scale: ", scaleFactor);
console.log("RScale: ",rScale.domain(), rScale.range());
console.log("r(1)", rScale(1) );
// */
var box = svg.append("rect")
.attr({ "height": height, "width":width,
"x":margin, "y":margin,
"class":"box"
});
var bubbleGroup = svg.append("g")
.attr("class", "bubbles")
.attr("transform",
"translate(" + [margin,margin] + ")");
//__Initialize layout objects__//
// Use the pack layout to initialize node positions:
d3.layout.pack()
.sort((
sortOrder?
( (sortOrder<0)?
function(a,b){return b.size - a.size;} : //descending
function(a,b){return a.size - b.size;} ) : //ascending
function(a,b){return 0;} //no sort
))
.size([width/scaleFactor, height/scaleFactor])
.value(function(d) { return d.size; })
.nodes({children:data});
//Use the force layout to optimize:
var force = d3.layout.force()
.nodes(data)
.size([width/scaleFactor, height/scaleFactor])
.gravity(.5)
.charge(0) //don't repel
.on("tick", updateBubbles);
//Create circles!//
var bubbles = bubbleGroup.selectAll("circle")
.data(data)
.enter()
.append("circle");
//Create text
var text = bubbleGroup.selectAll("text")
.data(data).enter().append("text")
.attr("dy", function(d){
return d.y;
})
.attr("dx", function(d){
return d.x;
}).style("text-anchor", "middle").text("test");
// Create a function for this tick round,
// with a new quadtree to detect collisions
// between a given data element and all
// others in the layout, or the walls of the box.
//keep track of max and min positions from the quadtree
var bubbleExtent;
function collide(alpha) {
var quadtree = d3.geom.quadtree(data);
var maxRadius = Math.sqrt(dataMax);
var scaledPadding = padding/scaleFactor;
var boxWidth = width/scaleFactor;
var boxHeight = height/scaleFactor;
//re-set max/min values to min=+infinity, max=-infinity:
bubbleExtent = [[Infinity, Infinity],[-Infinity, -Infinity]];
return function(d) {
//check if it is pushing out of box:
var r = Math.sqrt(d.size) + scaledPadding,
nx1 = d.x - r,
nx2 = d.x + r,
ny1 = d.y - r,
ny2 = d.y + r;
if (nx1 < 0) {
d.x = r;
}
if (nx2 > boxWidth) {
d.x = boxWidth - r;
}
if (ny1 < 0) {
d.y = r;
}
if (ny2 > boxHeight) {
d.y = boxHeight - r;
}
//check for collisions
r = r + maxRadius,
//radius to center of any possible conflicting nodes
nx1 = d.x - r,
nx2 = d.x + r,
ny1 = d.y - r,
ny2 = d.y + r;
quadtree.visit(function(quad, x1, y1, x2, y2) {
if (quad.point && (quad.point !== d)) {
var x = d.x - quad.point.x,
y = d.y - quad.point.y,
l = Math.sqrt(x * x + y * y),
r = Math.sqrt(d.size) + Math.sqrt(quad.point.size)
+ scaledPadding;
if (l < r) {
l = (l - r) / l * alpha;
d.x -= x *= l;
d.y -= y *= l;
quad.point.x += x;
quad.point.y += y;
}
}
return x1 > nx2 || x2 < nx1 || y1 > ny2 || y2 < ny1;
});
//update max and min
r = r-maxRadius; //return to radius for just this node
bubbleExtent[0][0] = Math.min(bubbleExtent[0][0],
d.x - r);
bubbleExtent[0][1] = Math.min(bubbleExtent[0][1],
d.y - r);
bubbleExtent[1][0] = Math.max(bubbleExtent[1][0],
d.x + r);
bubbleExtent[1][1] = Math.max(bubbleExtent[1][1],
d.y + r);
};
}
function updateBubbles() {
bubbles
.each( collide(0.5) ); //check for collisions
text.each(collide(0.5));//check for text collisions
//update the scale to squeeze in the box
//to match the current extent of the bubbles
var bubbleWidth = bubbleExtent[1][0] - bubbleExtent[0][0];
var bubbleHeight = bubbleExtent[1][1] - bubbleExtent[0][1];
scaleFactor = (height/bubbleHeight +
width/bubbleWidth)/2; //average
/*
console.log("Box dimensions:", [height, width]);
console.log("Bubble dimensions:", [bubbleHeight, bubbleWidth]);
console.log("ScaledBubble:", [scaleFactor*bubbleHeight,
scaleFactor*bubbleWidth]);
//*/
rScale
.range([0, Math.sqrt(dataMax)*scaleFactor]);
//shift the bubble cluster to the top left of the box
bubbles
.each( function(d){
d.x -= bubbleExtent[0][0];
d.y -= bubbleExtent[0][1];
});
//update positions and size according to current scale:
bubbles
.attr("r", function(d){return rScale(d.size);} )
.attr("cx", function(d){return scaleFactor*d.x;})
.attr("cy", function(d){return scaleFactor*d.y;});
text
.attr("dy", function(d){
return (scaleFactor*d.y)+4;
})
.attr("dx", function(d){
return scaleFactor*d.x*2;
});
}
force.start();
})();
rect.box {
fill:none;
stroke:royalblue;
stroke-width:5;
shape-rendering: crispEdges;
}
g.bubbles circle {
fill:rgba(255,0,64,0.5);
stroke:rgb(255,0,64);
stroke-width:3;
}
g.bubbles text {
fill:royalblue;
font-family:sans-serif;
text-anchor:middle;
alignment-baseline:middle;
opacity:1;
pointer-events:all;
transition:1s;
}
g.bubbles text:hover {
opacity:1;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
<svg height=500 width=500></svg>
I've added text to circles, and also collision behavior too.
Initially the text is invisible because in the CSS they mentioned like below
g.bubbles text {
fill:royalblue;
font-family:sans-serif;
text-anchor:middle;
alignment-baseline:middle;
opacity:0;//See this value, this makes text to invisible
pointer-events:all;
transition:1s;
}
g.bubbles text:hover {
opacity:1;
}
In my snippet I changed it visible by making it's opacity to 1.
And updated fiddle
I have a graph, and I want the line representing the graph to show a circle at the x coordinate when hovering on top of the svg area. This circle should follow the path of the line that represents the curve. The problem is that I don't know how to do this.
The code below shows how far I have succeded, and it indeed adds a circle to the document at the right x coordinate. Now, what do I replace the question mark with?
svg.on("mousemove", function() {
d3.select("path.line")
.style("stroke-width", "2.5px");
svg.append("svg:circle")
.attr("cx", Math.floor(event.offsetX-m[1]))
.attr("cy", ?)
.attr("r", "10")
.attr("fill", "red");
});
SVG provides a native function called .getPointAtLength() which returns a the x and y values of a path at any length you pass at it.
You would need to iterate through the length of the line until you find the corresponding y position. Here is how you would do it in D3:
var svg = d3.select("#line").append("svg")
var path =
svg.append("path")
.attr("d", "M0,168L28,95.99999999999997L56,192L84,71.99999999999997L112,120L140,192L168,240L196,168L224,48L252,24L280,192L308,120L336,24L364,168L392,95.99999999999997L420,168L448,95.99999999999997L476,192L504,71.99999999999997L532,120L560,192L588,216L616,168L644,48L672,24L700,192L728,120L756,24L784,192L812,71.99999999999997")
.attr("fill", "none")
.attr("stroke", "black");
var circle =
svg.append("circle")
.attr("cx", 100)
.attr("cy", 350)
.attr("r", 3)
.attr("fill", "red");
var pathEl = path.node();
var pathLength = pathEl.getTotalLength();
var BBox = pathEl.getBBox();
var scale = pathLength/BBox.width;
var offsetLeft = document.getElementById("line").offsetLeft;
var randomizeButton = d3.select("button");
svg.on("mousemove", function() {
var x = d3.event.pageX - offsetLeft;
var beginning = x, end = pathLength, target;
while (true) {
target = Math.floor((beginning + end) / 2);
pos = pathEl.getPointAtLength(target);
if ((target === end || target === beginning) && pos.x !== x) {
break;
}
if (pos.x > x) end = target;
else if (pos.x < x) beginning = target;
else break; //position found
}
circle
.attr("opacity", 1)
.attr("cx", x)
.attr("cy", pos.y);
});
You can see a demo here: http://bl.ocks.org/3824661