dc.js BarChart yAxis range plus padding - d3.js

I have a stack barchart and added an outline to the bars via
.dc-chart rect.bar {stroke: black;}
I have also defined
.elasticY(true)
The black outline at the top of the bar (xAxis 0) is chopped by a pixel compared to the top of the bar (xAxis 2). Is there anyway to pad the y max range by a little so I can see the outline and still keep elasticY?

Strangely enough, it's called yAxisPadding, and it's documented here. It does work with elasticY.
I guess the Markdown documentation is getting a little long to just browse. The HTML documentation is better if you know the particular class or mixin where the function might be defined. (Takes some practice.)
You can use either a number, in domain units:
chart.yAxisPadding(10)
or a percentage, as a string:
chart.yAxisPadding("5%")
Padding in domain units can lead to some surprises, though.

Related

Adding specific ticks on D3 axis w/ brush

I need help adding specific ticks to an axis that is also being focused with a brush. I found a similar question/answer for a static axis (without a brush) here:
Adding a specific tick to a D3.js axis
It's along the lines of what I'm trying to do. My chart is more similar to this example though :
http://blockbuilder.org/pergamonster/419aef09c21ffe8dd1dac971016468d6
Say you wanted to have a 'July 4' tick on both the full axis and the focus axis at all times. I've tried the axis.ticks().push(...arrayOfNumbers) from the above question/answer in my code, but nothing happens. If I do axis.tickValues(arrayOfNumbers) it puts ONLY those numbers as ticks, but I would like to have the auto scaling number PLUS my specific numbers on the axis for the focus area.
Any help would be appreciated.
P.S. Though my chart is similar the about blockBuilder example, I'm using a linearScale not a timeScale if that matters. Thanks
draw a second x-axis where you only specify the extra ticks.
svg.append('g')
.attr('class', 'x-axis-extra')
.attr("transform", `translate(0,${height})`)
.call(d3.axisBottom(xScale).tickValues([2.78,3.14]));
You need a bit of CSS to hide the extra path
.x-axis-extra path { opacity: 0; }

dimple.js: Tool-tip placement in a chart of a nested svg element

I am trying to modify Bullet Charts example of dimple.js with each bullet chart being in a child-svg of the parent-svg. Purpose of having individual svg for each bullet chart is to make their management (show/hide/remove) easier. Also, this makes the recursive definition of a chart complete - That is, a chart is contained by an svg.
The fiddle for the modified version is here....
As you can see, from 2nd chart onwards, on mouse hover, tool tips go out of place!!! Please note that, for child-svg, I've set the style overflow: visible without which tool-tips were not visible at all.
Want to know if I am missing anything in handling the attributes of child-svg elements or is it a bug in dimple.js. Also, please let me know if you know of any workaround.
Thanks.
One of the first questions I have is why do you want child svg elements? What are you trying to accomplish?
The only difference I see in your code and the example is the height / width swap at the top and the sub svg + bounds.
Keep in mind that the origin changes with each sub-svg. This might be why you are having trouble with the tool-tips. Maybe you have that worked into your add-bullet calls.
I think nagu has the right approach here if you really want separate svg elements.

Chart-like object (but not a gantt or stacked bar chart) in d3 -- where to start?

I have a chart I've created in excel that I'd like to replicate in d3, but I'm not sure where I should begin.
It's intended to show which character is speaking at which moment during a play, and so it visually looks similar to a gantt chart or stacked bar chart but it isn't working off of time the way a gantt chart would. Am I right in thinking that it'd be a bar chart or series of bar charts? Could I build it up by a series of 1 pixel wide bars, so that each pixel would equal a line in the play?
I'd provide code but I tried to modify the standard stacked bar chart and all I've really been able to do is either make the whole thing blank or modify the canvas dimensions. So I'd appreciate some suggestions to get me started.
it seems to me that the only (and big!) trouble you'll have here is creating the JSON. Once you have the JSON, it will be a piece of cake! Here is what I thought:
Create a very big JSON that is just 1 big array of hundreds of objects. Each object would be like this:
{"character": "John Doe", "place": "tavern", "duration": 5}
Then, you'll append the narrow rectangles using an ordinal scale for the places ("place") on y axis, setting the x position according to the cumulative duration of previous speeches and setting the width using the duration of each speech, and using CSS you can color the bars according to the character (using character for setting the class).
For this, you would use D3 only for the scales, avoiding the typical selection().data().enter().append() pattern and appending each rectangle in a for loop. Let me explain. Suppose you put your JSON in a variable named data. Then, you do:
for (var i = 0; i < data.length; i++){
var speech = data[i]
//rest of the code
}
This allow you, for each loop, to know the y position of the bar using speech.place, the name of the character using speech.character, for the colors, and the duration of the line using speech.duration. For calculating the x position, you declare a var duration; outside the loop and, inside it, you write:
duration += speech.duration;
In this approach, once you would use the cumulative duration for x position, the objects in the array must to be in the exact chronological order of the play.
PS: D3 is so nice that you can create an additional value named "line", for each object, with the actual line spoken by the character, and when the user hover over the rectangle he/she will see the text of the speech!

d3.event.y has strange values during drag behavior

I'm creating an example illustrating a layout with resizeable cells using the D3 drag behaviour and CSS {display: table} styles. It works fine for dragging horizontally, but not vertically. For vertical resizing, d3.event.y is providing values that do not make sense to me.
Here is a fiddle showing the working horizontal drag and the broken vertical drag. Take a look at the console output while dragging to see that the values returned by d3.event match the values returned by d3.mouse() for the horizontal drag, but they diverge for the vertical drag.
I can fix the behaviour by using the d3.mouse() y-coordinate instead of the d3.event y-coordinate. To see this, comment out the "DOESN'T WORK" line and uncomment the "WORKS" line. However, I don't understand why I need to do this, and it seems less general in that I have to assume a mouse input instead of using the more generic d3.event.
Is this a bug, or am I failing to understand something here?
Note that this question seems to be hitting the same issue, but using HTML tables instead of CSS tables. I thought it would be helpful to document that this problem is occurring in both contexts.
Also note that commenting out the two lines that actually do the vertical resizing, commented with "RESIZE CELLS", makes the d3.event work correctly. Of course, the table doesn't get resized then. This suggests that it is something about the act of resizing the divs that is leading d3.event astray.
Alright, I think I've figured out the issue. If you look at the code for drag behavior, you'll notice in dragstart that the value used to calculate the mouse offset is based off this.parentNode. In short, it uses this.parentNode as a reference point, and assumes that it's going to be stable for the duration of the drag. You're modifying the parent nodes during the drag, so its reference point gets, to put it technically, pretty borked. In this case, using d3.mouse is your best bet, since d3.event.y is only going to be reliable as long as the parent node stays in place.
The reason this only happens in the y direction for you is that the x position of all the rows, which are the parent nodes here, stay constant, whereas the y component changes during the drag.
The relevant code sections:
parent = that.parentNode,
function moved() {
var position1 = position(parent, dragId), dx, dy;
//...
dispatch({
type: "drag",
x: position1[0] + dragOffset[0],
y: position1[1] + dragOffset[1],
dx: dx,
dy: dy
});

NVD3.js multiChart x-axis labels is aligned to multiple lines, but not multiple bars

This question relates to NVD3.js multiChart x-axis labels is aligned to lines, but not bars
I am using NVD3.js multiChart to show multiple lines and multiple 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:
As you can see - x-axis (example, 2014-Feb) is not aligned to Bars.
1) How to align x-axis labels to bars and lines at the same time?
2) I need this solution for NVD3.js or how to properly integrate.
I made jsFiddle: http://jsfiddle.net/n2hfN/28/
Thanks!
The problem here is that nv.models.multiChart uses a linear scale for its x-axis, and then when it draws the bars it calls nv.models.multiBar, which uses an ordinal scale with .rangeBands().
You can follow this mess through the source code:
First lets look at multiChart.js
HERE is where it sets the x-scale to be a linear scale.
HERE it calls the nv.models.multiBar model to create the bars.
If we jump over to have a look at multiBar.js
HERE it creates an ordinal scale, and HERE it sets the range of the scale using .rangeBands()
The result is that the ordinal scale used for placing the bars, and the linear scale used for the chart's axis do not align. Here's what the two scales look like on their own if plotted on an axis:
The solution would be to force the chart to render the line graphs and the x-axis in terms of the ordinal scale used by the bars. This would work in your case because the bars and the lines all use the same data for the x-axis. This is very simple to do if you are making your own chart and not relying on nvd3, as I showed in my answer to your previous question HERE. This is extraordinarily complicated to do if you're trying to work within nvd3, and many others have tried and failed to switch out the default scales used by nvd3 charts. Have a look at this issue on the nvd3 github page that has been open since January, 2013 for example.
I've tried a number of approaches myself to reuse the bars' ordinal scale, but with little success. If you want to poke around and try to brute-force it yourself, I can tell you that from my experiments I came closest when using chart.bars1.xScale().copy() to make a copy of the bars' scale, and set its domain and rangeBands. Unfortunately, since the chart's width is computed at render time, and I can't seem to create a hook into the chart.update function, it is impossible to set the rangeBands' extent to the correct values.
In short, if you can't live with the labels being offset, you're probably going to need to code up your own chart without nvd3, or else find a different type of layout for your visualization.
After playing around with the NVD3 v1.7.1 source code with the immensely helpful guidance offered by jshanley's answer, I think I've managed to come up with an answer (perhaps more of a kludge than a good solution).
What I did was to have the x-axis labels align with the bars, and have the line data points align with the bars.
1.1. To align the x-axis label, I shifted the x-axis to the right so that the first label appears underneath the middle of the first bar. I then shifted the last label to the left, so that it appears underneath the middle of the last bar. See code here. The amount to shift by is computed at drawing time using .rangeBand() and saved in a rbcOffset variable (I had to modify multiBar.js for this to work).
1.2. To align the line data points with the bars, a similar shift is also required. Luckily, this part is easy because scatter.js (which is used by line chart) comes with a padData boolean variable that does what we want already. So basically, I just set padData to true and the lines shift to align with the bars, see here.
In order to properly integrate with NVD3 and make everything look good, some additional changes are required. I've forked NVD3 on GitHub so you can see the complete solution there. Of course, contributions are welcome.
I use last solution and it runs. So, you can specify
lines1.padData(true)
in order to align lines too.
Same here, I used the last solution,it worked for me as well. Find the following line in multiChart.js
if(dataLines1.length){
lines1.scatter.padData(true); // add this code to make the line in sync with the bar
d3.transition(lines1Wrap).call(lines1);
}
I encountered the same problem and fixed it with below code:
at lines 7832 and 7878 replace
.attr('transform', function(d,i) { return 'translate(' + x(getX(d,i)) + ',0)'; })
with :
var w = (x.rangeBand() / (stacked && !data[j].nonStackable ? 1 : data.length));
var sectionWidth = availableWidth/(bars.enter()[0].length - 1);
if(bars.enter().length == 2)
return 'translate(' + ((i-1)*w + i*w + (i*(sectionWidth - 2*w))) + ',0)';
else
return 'translate(' + ((i-0.5)*w + i*(sectionWidth - w)) + ',0)';
The first case handles multiple bars case while the second one handles single bar case.
lawry's solution works. Also if using interactive guidelines, you need to shift the interactive line to match the new scale. Modify:
if(useInteractiveGuideline){
interactiveLayer
.width(availableWidth)
.height(availableHeight)
.margin({left:margin.left, top:margin.top})
.svgContainer(container)
.xScale(x);
wrap.select(".nv-interactive").call(interactiveLayer);
//ADD THIS LINE
wrap.select(".nv-interactiveGuideLine")
.attr('transform', 'translate(' + rbcOffset +', ' + 0 + ')' +
'scale(' + ((availableWidth - rbcOffset*2)/availableWidth) + ', 1)');
}
in multiChart.js.

Resources