I am using the code snippet from this stackoverflow question to label my flot data points. So far this has served me well, but now I have to label the overall values of stacked bars. There are two data series and so far I've managed to calculate the sums, but I can't seem to work out a proper positioning for my labels. I'd like to place them on top of the stacks, but pointOffset only gives me the offsets based on non-stacked bars.
This is the code I am currently using, it places the labels where the second series' data points would be, if the bars weren't stacked, which puts them somewhere in the top bars.
$.each(p.getData()[1].data, function(i, el){
var series0 = p.getData()[0].data;
sum = el[1] + series0[i][2]
var o = p.pointOffset({x: el[0], y: el[1]});
$('<div class="data-point-label">' + sum + '</div>').css( {
position: 'absolute',
left: o.left - 5,
top: o.top ,
display: 'none'
}).appendTo(p.getPlaceholder()).fadeIn('slow');
});
Edit #1: So far I've tried using c2p/p2c, calculating the top value using the single data points' top values and finding more documentation on the stack plugin. I am afraid none of this has helped me much.
Edit #2: I've also tried the code given in this stackoverflow answer but it doesn't work for me. I suspect the author is using some label plugin ...
The solution to put the labels in the top of the bars in stack usinjg canvas is that you have to calculate the xPoint in base of the sum of the values in the complete stack.
Here is a example of code
var sumaArr = [];
for (var u = 0; u < p.getData().length; u++) {
$.each(p.getData()[u].data, function (i, el) {
sumaArr[i] > 0 ? sumaArr[i] = sumaArr[i] + el[1] : sumaArr[i] = el[1];
});
}
var ctx = p.getCanvas().getContext("2d");
var data = p.getData()[p.getData().length - 1].data;
var xaxis = p.getXAxes()[0];
var yaxis = p.getYAxes()[0];
var offset = p.getPlotOffset();
ctx.font = "12px 'Segoe UI'";
ctx.fillStyle = "gray";
for (var i = 0; i < data.length; i++) {
var text = sumaArr[i];
var metrics = ctx.measureText(text);
var xPos = (xaxis.p2c(data[i][0]) + offset.left) - metrics.width / 2;
var yPos = yaxis.p2c(sumaArr[i]) + offset.top - 5;
ctx.fillText(text, xPos, yPos);
}
The var yPos use the sume of the values that make the complete stack.
Related
I am adding images using chart.renderer.image. I would like the images to line up with the beginning of each plotBand. I have the plotBand from position in axis units. However when I call toValue the images do not line up.
https://jsfiddle.net/uxeL76a9/23/
for (var i = 0; i < plotBands.length; ++i) {
var artist = plotBands[i];
var xPos = chart.xAxis[0].toValue(artist['from'], true);
...
Your chart is inverted, so axes are swapped, and you have small mess with toValue(), see fixed code:
var xPos = chart.xAxis[0].toValue(artist['from'], true);
Should be:
var xPos = chart.yAxis[0].toPixels(artist.from);
Working demo: https://jsfiddle.net/uxeL76a9/40/
I have a working jsfiddle that I made using JSXGraph, a graphing toolkit for mathematical functions. I'd like to port it to D3.js for personal edification, but I'm having a hard time getting started.
The jsfiddle graphs the value of -ke(-x/T) + k, where x is an independent variable and the values of k and t come from sliders.
board.create('functiongraph',
[
// y = -k * e(-x/t) + k
function(x) { return -k.Value()*Math.exp(-x/t.Value()) + k.Value(); },
0
]
);
The three things I'm most stumped on:
Actually drawing the graph and its axes - it's not clear to me which of the many parts of the D3 API I should be using, or what level of abstraction I should be operating at.
Re-rendering the graph when a slider is changed, and making the graph aware of the value of the sliders.
Zooming out the graph so that the asymptote defined by y = k is always visible and not within the top 15% of the graph. I do this now with:
function getAestheticBoundingBox() {
var kMag = k.Value();
var tMag = t.Value();
var safeMinimum = 10;
var limit = Math.max(safeMinimum, 1.15 * Math.max(k.Value(), t.Value()));
return [0, Math.ceil(limit), Math.ceil(limit), 0];
}
What's the right way for me to tackle this problem?
I threw this example together really quick, so don't ding me on the code quality. But it should give you a good starting point for how you'd do something like this in d3. I implemented everything in straight d3, even the sliders.
As #LarKotthoff says, the key is that you have to loop your function and build your data:
// define your function
var func = function(x) {
return -sliders.k() * Math.exp(-x / sliders.t()) + sliders.k();
},
// your step for looping function
step = 0.01;
drawPlot();
function drawPlot() {
// avoid first callback before both sliders are created
if (!sliders.k ||
!sliders.t) return;
// set your limits
var kMag = sliders.k();
var tMag = sliders.t();
var safeMinimum = 10;
var limit = Math.max(safeMinimum, 1.15 * Math.max(kMag, tMag));
// generate your data
var data = [];
for (var i = 0; i < limit; i += step) {
data.push({
x: i,
y: func(i)
})
}
// set our axis limits
y.domain(
[0, Math.ceil(limit)]
);
x.domain(
[0, Math.ceil(limit)]
);
// redraw axis
svg.selectAll("g.y.axis").call(yAxis);
svg.selectAll("g.x.axis").call(xAxis);
// redraw line
svg.select('.myLine')
.attr('d', lineFunc(data))
}
Is there any way to find inversion of ordinal scale?
I am using string value on x axis which is using ordinal scale and i on mouse move i want to find inversion with x axis to find which string is there at mouse position?
Is there any way to find this?
var barLabels = dataset.map(function(datum) {
return datum.image;
});
console.log(barLabels);
var imageScale = d3.scale.ordinal()
.domain(barLabels)
.rangeRoundBands([0, w], 0.1);
// divides bands equally among total width, with 10% spacing.
console.log("imageScale....................");
console.log(imageScale.domain());
.
.
var xPos = d3.mouse(this)[0];
xScale.invert(xPos);
I actually think it doesn't make sense that there isn't an invert method for ordinal scales, but you can figure it out using the ordinal.range() method, which will give you back the start values for each bar, and the ordinal.rangeBand() method for their width.
Example here:
http://fiddle.jshell.net/dMpbh/2/
The relevant code is
.on("click", function(d,i) {
var xPos = d3.mouse(this)[0];
console.log("Clicked at " + xPos);
//console.log(imageScale.invert(xPos));
var leftEdges = imageScale.range();
var width = imageScale.rangeBand();
var j;
for(j=0; xPos > (leftEdges[j] + width); j++) {}
//do nothing, just increment j until case fails
console.log("Clicked on " + imageScale.domain()[j]);
});
I found a shorter implementation here in this rejected pull request which worked perfectly.
var ypos = domain[d3.bisect(range, xpos) - 1];
where domain and range are scale domain and range:
var domain = x.domain(),
range = x.range();
I have in the past reversed the domain and range when this is needed
> var a = d3.scale.linear().domain([0,100]).range([0, w]);
> var b = d3.scale.linear().domain([0,w]).range([0, 100]);
> b(a(5));
5
However with ordinal the answer is not as simple. I have checked the documentation & code and it does not seem to be a simple way. I would start by mapping the items from the domain and working out the start and stop point. Here is a start.
imageScale.domain().map(function(d){
return {
'item':d,
'start':imageScale(d)
};
})
Consider posting your question as a feature request at https://github.com/mbostock/d3/issues?state=open in case
There is sufficient demand for such feature
That I haven't overlooked anything or that there is something more hidden below the documentation that would help in this case
If you just want to know which mouse position corresponds to which data, then d3 is already doing that for you.
.on("click", function(d,i) {
console.log("Clicked on " + d);
});
I have updated the Fiddle from #AmeliaBR http://fiddle.jshell.net/dMpbh/17/
I recently found myself in the same situation as OP.
I needed to get the inverse of a categorical scale for a slider. The slider has 3 discrete values and looks and behaves like a three-way toggle switch. It changes the blending mode on some SVG elements. I created an inverse scale with scaleQuantize() as follows:
var modeArray = ["normal", "multiply", "screen"];
var modeScale = d3.scalePoint()
.domain(modeArray)
.range([0, 120]);
var inverseModeScale = d3.scaleQuantize()
.domain(modeScale.range())
.range(modeScale.domain());
I feed this inverseModeScale the mouse x-position (d3.mouse(this)[0]) on drag:
.call( d3.drag()
.on("start.interrupt", function() { modeSlider.interrupt(); })
.on("start drag", function() { inverseModeScale(d3.mouse(this)[0]); })
)
It returns the element from modeArray that is closest to the mouse's x-position. Even if that value is out of bounds (-400 or 940), it returns the correct element.
Answer may seem a bit specific to sliders but posting anyway because it's valid (I think) and this question is in the top results for " d3 invert ordinal " on Google.
Note: This answer uses d3 v4.
I understand why Mike Bostock may be reluctant to include invert on ordinal scales since you can't return a singular true value. However, here is my version of it.
The function takes a position and returns the surrounding datums. Maybe I'll follow up with a binary search version later :-)
function ordinalInvert(pos, scale) {
var previous = null
var domain = scale.domain()
for(idx in domain) {
if(scale(datum[idx]) > pos) {
return [previous, datum[idx]];
}
previous = datum[idx];
}
return [previous, null];
}
I solved it by constructing a second linear scale with the same domain and range, and then calling invert on that.
var scale = d3.scale.ordinal()
.domain(domain)
.range(range);
var continousScale = d3.scale.linear()
.domain(domain)
.range(range)
var data = _.map(range, function(i) {
return continousScale.invert(i);
});
You can easily get the object's index/data in callback
.on("click", function(d,i) {
console.log("Clicked on index = " + i);
console.log("Clicked on data = " + d);
// d == imageScale.domain()[1]
});
d is the invert value itself.
You don't need to use obj.domain()[index] .
I have just started using jqPlot for a line chart with multiple series. It seems great.
I have added the Cursor plugin with the intention of showing a vertical line on the nearest data point on the x axis. In other words, it snaps to the nearest point. The Cursor plugin, however always shows the vertical cursor right where the mouse is.
It seems like I just want to "override" or replace moveLine to change the current functionality.
What's the most appropriate way of doing so?
It seems a little much to copy/past all of the cursor plugin just to modify a very small subset.
Thanks!
I know I'm a kind of archaeologist by edited this post but I think the following can be useful for someone (I hope).
I've made a piece of code which allow to draw a vertical line following the cursor and displaying a tooltip on the nearest point (according to the cursor). You can find a demo of it on this JSFiddle.
I also post the corresponding code below (only the part which calculate nearest point and display tooltip):
//Show nearest point's tooltip
$("#chart1").bind('jqplotMouseMove', function(ev, gridpos, datapos, neighbor, data){
var c_x = datapos.xaxis;
var index_x = -1;
var pos_index = 0;
var low = 0;
var high = data.data[0].length-1;
while(high - low > 1){
var mid = Math.round((low+high)/2);
var current = data.data[0][mid][0];
if(current <= c_x)
low = mid;
else
high = mid;
}
if(data.data[0][low][0] == c_x){
high = low;
index_x = high;
}else{
var c_low = data.data[0][low][0];
var c_high = data.data[0][high][0];
if(Math.abs(c_low - c_x) < Math.abs(c_high - c_x)){
index_x = low;
}else{
index_x = high;
}
}
//Display marker and tooltip
if(data.series[0].data[index_x]){
var x = data.series[0].gridData[index_x][0];
var y = data.series[0].gridData[index_x][1];
var r = 5;
var highlightCanvas = $(".jqplot-highlight-canvas")[0];
var context = highlightCanvas.getContext('2d');
context.clearRect(0,0,highlightCanvas.width,highlightCanvas.height);
context.strokeStyle = 'rgba(47,164,255,1)';
context.fillStyle = 'rgba(47,164,255,1)';
context.beginPath();
context.arc(x,y,r,0,Math.PI*2,true);
context.closePath();
context.stroke();
context.fill();
//Display tooltip on nearest point
var highlightTooltip = $(".jqplot-highlighter-tooltip");
var val_x = data.data[0][index_x][0];
var val_y = data.data[0][index_x][1];
highlightTooltip.html("X : "+val_x+"<br/>Y : "+val_y);
highlightTooltip.css({'left': x+'px', 'top': (y-10)+'px', 'display': 'block'});
}
});
Feel please to use it and to modify it as you need it.
Try a bar graph series on top of everything else that has alpha set to 0.
I'm using a single kendoChart to display up to 10 lines of data.
Each line represents process data that may have widely different context and min/max ranges, but all lines are related in time, the categoryAxis. When displayed, each valueAxis correctly shows the scale for the corresponding line.
However, with 10 lines, the 10 valueAxes take up far too much of the screen to be usable for my requirements.
I tried hiding all axes except one with the expectation that the chart would expand to fill up the space taken by the hidden axes, but that does
not happen. I get a lone axis surrounded by blank space and the chart's plot area remains the same size.
I tried setting all of the series to use the same valueAxis and then varying the valueAxis min/max per the active channel as chosen by clicking
a legend item. This expands the plot area as needed, but removes the ability to see all lines since the scale is specific to one line.
Is it possible for kendoChart to show multiple plots independently from a single valueAxis (e.g. a line with values between 0.5 and 0.7 would appear scaled to the full chart area, and so would a line with values between 25 and 100, but the valueAxis might display either scale.)
The solution I used for this problem is more code than I expected to need. Perhaps Telerik's other products have an API for this.
Essentially, I maintain a structure outside of the kendoChart that stores the real data for each series, and this real data is mapped to the expected scale of the currently visible valueAxis. The mapping function is the standard transform from one scale into another.
The valueAxis is 'swapped' depending on which legend item is clicked, and that event triggers a redraw on the chart where all the series data is mapped to the 'active' axis.
Some code snippets. A series is also described as a channel.
// The data structure.
this._channelDescriptors.push({
fullName: ch.fullName || "",
axisTitle: (ch.fullName + axisEUString) || "",
axisFont: ch.axisFont || "",
axisColor: ch.color || "#000000",
realData: [],
minData: Number.MAX_VALUE,
maxData: Number.MIN_VALUE
});
// This event causes the switching of valueAxis for all members of the series.
$("#" + chartID).kendoChart({
// Other kendoChart configurations
//
legendItemClick: function (e) {
var idx = e.seriesIndex;
sncTrender.updateAxis(idx);
e.preventDefault();
},
tooltip: {
visible: true,
template: "#=series.name# : #=kendo.format('{0:N4}', dataItem.realValue)#<br />#=kendo.format('{0:MM-dd HH:mm:ss.fff}', dataItem.Time)#",
},
//
// Other kendoChart configurations
});
// All code snippets are members of a wrapper object.
updateAxis: function (ch) {
if (this.series[ch].visible) {
this.setAxis(ch);
}
},
// Every series is set to the same valueAxis via the selected series' valueAxis.name property.
setAxis: function (ch) {
var i,
channel = this._channelDescriptors[ch];
this._currentChannel = ch;
for (i = 0; i < this.series.length; i++) {
this.series[i].axis = this._channelDescriptors[ch].fullName;
}
// Set the active valueAxis properties. This is the only axis visible maintained for the chart.
this.valueAxis.name = channel.fullName;
this.valueAxis.title.text = channel.axisTitle;
this.valueAxis.title.font = channel.axisFont;
this.valueAxis.line.color = channel.axisColor;
},
// The mapping occurs here, and the transform calculation is this line
// Y: (yRange * (chDesc.realData[k].realValue - newMin) / newRange) + this.valueAxis.min,
//
updateChart: function (allTrends) {
// ...
timeStamps = trendDataResponse.curve.Timestamp;
t1 = trendArgs.t1;
t2 = trendArgs.t2;
xValues = trendDataResponse.curve.X;
yValues = trendDataResponse.curve.Y;
pointCount = xValues.length;
min = Number.MAX_VALUE;
max = Number.MIN_VALUE;
categoryTimes = [pointCount];
newData = [];
for (l = 0; l < pointCount; l++) {
min = Math.min(min, yValues[l]);
max = Math.max(max, yValues[l]);
ts = new Date(timeStamps[l]);
categoryTimes[l] = ts;
// The Y data will be plotted on the chart, but the cursor tooltip will
// use the realValue data. In this way, the series can be visible regardless of
// the valueAxis scaling, but the actual data is also available. Refer to the
// tooltip template.
newData.push({ X: xValues[l], Y: yValues[l], realValue: yValues[l], Time: ts });
}
// Real data for each channel is stored in channelDescriptors.
chDesc = this._channelDescriptors[channelID];
chDesc.realData = newData;
chDesc.minData = min;
chDesc.maxData = max;
// The valueAxis min/max is set only for the 'active' series.
if (this._currentChannel === channelID) {
this.categoryAxis.categories = categoryTimes;
yRange = max - min;
scaleAdjustment = yRange * SNC.CONST_yAxisScaleAdjustmentFactor;
this.valueAxis.min = min - scaleAdjustment;
this.valueAxis.max = max + scaleAdjustment;
}
}
// Scale curves to current axis.
// Use real data for the current series.
for (j = 0; j < this.series.length; ++j) {
chDesc = this._channelDescriptors[j];
if (j === this._currentChannel) {
this.series[j].data = chDesc.realData;
continue;
}
// Use mapped data for all other series.
recalcData = [];
newMin = chDesc.minData;
newMax = chDesc.maxData;
newRange = newMax - newMin;
rangeAdjustment = newRange * SNC.CONST_yAxisScaleAdjustmentFactor;
newMin = newMin - rangeAdjustment;
newMax = newMax + rangeAdjustment;
for (k = 0; k < chDesc.realData.length; ++k) {
recalcData.push({
X: chDesc.realData[k].X,
Y: (yRange * (chDesc.realData[k].realValue - newMin) / newRange) + this.valueAxis.min,
realValue: chDesc.realData[k].realValue,
Time: chDesc.realData[k].Time,
});
}
this.series[j].data = recalcData;
}
chart.redraw();
}