I have a composite graph of two line charts. For one of them i'm attempting to apply a custom color range based on the value of each point on the line:
.colors(['rgb(215,48,39)','rgb(244,109,67)','rgb(253,174,97)','rgb(254,224,144)'])
.colorDomain ([0,3])
.colorAccessor (d,i) ->
if d.points[i].data.value.avg > 50
return 0
else
return 3
The problem is I keep getting only one color for the entire graph... Not to mention d returns as an object of all the points instead of a single point... (maybe a hint of the problem?)
Am i doing something wrong here and/or is there an easier way to do this?
You didn't get an answer so I'll try to look into it with you.
First, I created a fiddle at http://jsfiddle.net/djmartin_umich/4ZwaG/.
.colors( ['rgb(215,48,39)', 'rgb(244,109,67)', 'rgb(253,174,97)', 'rgb(254,224,144)' ] )
.colorDomain ([0,3])
.colorAccessor(function(d, i){
if(d[i] && d[i].data.value > 150)
return 3;
else if(d.data.value > 150)
return 2;
else return 1;
});
I had to play around with the color accessor to get it to stop throwing errors. The method was called twice with an array of elements and twice for each element in the array (24 times total).
Once I got it compiling I inspected the chart and saw this:
The chart has a path element that defines the line and a bunch of circles that define the points on the line. The points are part of the tool-tip that display when you hover over the different points on the line.
The path seems to be colored by the value returned when the array of values was passed in and the hover-points on the line are each colored by the value returned for that element.
So the path of the line is given a single color. It sounds like your expectation is for different portions of the line to be colored differently based on their y-value, but this is not how the line is rendered.
The article at http://www.d3noob.org/2013/01/applying-colour-gradient-to-graph-line.html describes how you can use gradients to achieve the effect you desire. I believe the author is "hard-coding" the start and stop points for each gradient, so it won't get you all the way to your answer but it should help you get started.
I hope this helps!
-DJ
Related
I am trying to filter data on my choropleth chart from a bargraph. Strange thing is that it is not showing correct value on selecting a bar from the accompanying bar chart.
Here is the jsfiddle: https://jsfiddle.net/anmolkoul/jk8LammL/
The script code begins from line 4794
If i select WIN004 from the bar chart, it should highlight only five states and the tooltip should reflect the values for the data. Some states are highlighted for whom WIN004 does not exist.
I changed the properties of the choropleth from
.colors(d3.scale.quantize().range(["#F90D00", "#F63F00", "#F36F01", "#F09E01", "#EDCB02", "#DDEA03", "#ADE703", "#7EE404", "#50E104", "#24DE05", "#05DB11"]))
.colorDomain([-1, 1])
To
.colors(d3.scale.linear().range(["green", "white", "red"]))
.colorDomain([-2, 0, 2])
But i get a lot of white states where its hard to discern what has been highlighted. The tool tip for some white-ed-out states show -0.00 :/
Here is the fiddle http://jsfiddle.net/anmolkoul/jk8LammL/1/
So i guess either its a problem with my color range or how my data is getting parsed.
I would ideally like to specify the data ranges in the .colorDomain based on the top and bottom values of the riskIndicator dimension. My functions are not working though. Should i use d3.max or riskIndicator.top here?
EDIT:
I got the color domain dynamic by using the min and max values but still the graph is not performing as expected? Could this be an issue with the geochoropleth chart? I further took a working geochoropleth example and ported my data to it and even that gave me the same issue of representing data incorrectly. I thoughit could be a data problem but i validated using a couple of good BI tools and their map charts displayed data correctly.
Could this be an issue with the dc choropleth?
Thank you.
Anmol
This has the same root cause as the issue in this question:
Crossfilter showing negative numbers on dc.js with no negative numbers in the dataset
In short, floating point numbers don't always cancel out to zero when added and subtracted. This "fake group" will ensure they snap to zero when they get close:
function snap_to_zero(source_group) {
return {
all:function () {
return source_group.all().map(function(d) {
return {key: d.key,
value: (Math.abs(d.value)<1e-6) ? 0 : d.value};
});
}
};
}
Added it to the FAQ!
I am trying to modify this D3 example to use with my dataset
http://mbostock.github.io/d3/talk/20111116/airports.html
I think my problem is creating the array of coordinates for calculating the Voronoi polygons, but at this point I'm not sure.
I'm getting a Uncaught TypeError: Cannot read property '0' of undefined error that points to the line where I am calling the array. The code is live, please see here
http://cds.library.brown.edu/projects/mapping-genres/symbol-maps/brown-voronoi-map.html
The map displays just fine, but the data points, the radio button, and the voronoi lines do not appear (I'm not trying to show lines between data points, so that code has been removed).
Any thoughts or suggestions would be most appreciated. Many thanks!
There are a number of small things going on here which can be easily sorted out but some will require a bit of work. The first is that you're using a new version of d3 (v3) and the example you're trying to replicate is an older version. There have been significant changes between the versions on the mapping side of things. So you can either use an old version of d3 (v2 will work I think) or investigate the changes.
The Uncaught TypeError: Cannot read property '0' of undefined error is being generated because d3.geom.voronoi(positions) line is producing NaN. I'm not 100% sure why but you could just filter these out to get a temporary fix. A simple filter would be something like:
g.append("svg:path")
.attr("class", "cell")
.attr("d", function(d, i) {
if (polygons[i][0][0]) {
return "M" + polygons[i].join("L") + "Z";
}
})
with the if true when there is not a false value (NULL, NaN, etc) in the first element of the polygon. Please note that this is temporary fix while you investigate why you're getting NaN and this will not produce the correct voronoi polygons.
The fix for the data points is very simple, you just have to set the radius to something greater than 0 such as 10 (although I imagine that you might want to scale the dots to a property of your data like TotalPublished). For instance see the last line:
circles.selectAll("circle")
.data(locations.rows
.sort(function(a, b) { return b.TotalPublished - a.TotalPublished; }))
.enter().append("svg:circle")
.attr("transform", function(d) { return "translate(" + projection(d.coordinates) + ")"; })
.attr("r", 10);
The radio button (or checkbox) does not show up as it's not generated by the javascript (although it can be). In the example you refer to its generated in the html in this snippet:
<div style="position:absolute;bottom:0;font-size:18px;">
<input type="checkbox" id="voronoi"> <label for="voronoi">show Voronoi</label>
</div>
Once you've worked through this you'll need to get the voronoi lines working. I think with your code as is the voronoi lines won't show up as the checkbox is not checked. So you could comment these lines out and see what happens. A quick tip with paths is that if you want to just show the lines you need to set the fill style to none and the stroke to whatever colour you want. If you don't set the fill to none you'll just get a black screen.
Is there a way in d3 to not draw overlapping tick labels? For example, if I have a bar chart, but the bars are only 5 pixels wide and the labels are 10 pixels wide, I end up with a cluttered mess. I'm currently working on an implementation to only draw the labels when they do not overlap. I can't find any existing way to do that, but wasn't sure if anyone else had dealt with this problem.
There is no way of doing this automatically in D3. You can set the number of ticks or the tick values explicitly (see the documentation), but you'll have to figure out the respective numbers/values yourself. Another option would be to rotate the labels such that there is less chance of them overlapping.
Alternatively, like suggested in the other answer, you could try using a force layout to place the labels. To clarify, you would use the force layout on the labels only -- this is completely independent of the type of chart. I have done this in this example, which is slightly more relevant than the one linked in the other answer.
Note that if you go with the force layout solution, you don't have to animate the position of the labels. You could simply compute the force layout until it converges and then plot the labels.
I've had a similar problem with multiple (sub-)axis, where the last tick overlaps my vertical axis in some situations (depending on the screen width), so I've just wrote a little function that compares the position of the end of the text label with the position of the next axis. This code is very specific to my use case, but could adapted easily to your needs:
var $svg = $('#svg');
// get the last tick of each of my sub-axis
$('.tick-axis').find('.tick:last-of-type').each(function() {
// get position of the end of this text field
var endOfTextField = $(this).offset().left + $(this).find('text').width();
// get the next vertical axis
var $nextAxis = $('line[data-axis="' + $(this).closest('.tick-axis').attr('data-axis') + '"]');
// there is no axis on the very right, so just use the svg width
var positionOfAxis = ($nextAxis.length > 0) ? $nextAxis.offset().left : $svg.offset().left + $svg.width();
// hide the ugly ones!
if (endOfTextField > positionOfAxis) {
$(this).attr('class', 'tick hide');
}
});
The ticks with color: aqua are the hidden ones:
I am trying to use d3 to animate text using an svg text with d3 transitions. I have it working as desired for a single string.
I want to iterate through strings from an array of json objects.
I can do this as well.
All the painting and transitions work great. Problem is, they all happen at once, and appear piled up on each other, and all animate all at once.
I have tried putting them in a setTimeout() to get them to appear sequentially.
Still does not work.
for ( i in haikuStr ) {
if( i !=0 ){
//Make it wait if an appropriate time it is not the first one
setTimeout( function() {
showText();
}, 11000 * i );
} else {
//if i=0, don't make folks wait
showText();
}
}
The showText() function is the full create container -> finish transitions.
I use 11000 * i to ensure that >2 iterations have 11 additional seconds per i.
I have spent quite a bit of time reading and trying to figure out how to get the loop to pause before cycling through to paint the next line.
Any thoughts or ideas would be appreciated.
The un-timed example is here, if you wish to see the text jumble up:
http://www.mysalmagundi.com/js/svg-d3-no-timing.html
Have you read Thinking with Joins? Or some of the other introductory D3 tutorials, such as those by Scott Murray? Or Three Little Circles, or Working with Selections? I ask because your showText function is misusing data joins; it creates text elements for every element in the global haikuStr array:
var text = haikuContainer.selectAll("text")
.data(haikuStr)
.html(String)
.enter().append("text");
And all your text elements are overlapping because you set them to have the same y-attribute:
var thisHaiku = text
.attr("x", -800)
.attr("y", 120)
(Also, that selection.html call is a no-op because the update selection is guaranteed to be empty, since you just created haikuContainer it is guaranteed to not have any descendant text elements. And thisHaiku is the same value as the var text, because when method chaining selection.attr and similar methods return the current selection; so there’s no reason to create a separate var. Also, you shouldn’t use a for-in loop to iterate over arrays.)
If you wait 11 seconds, you’ll see the second SVG appear, but because of your data join as described above, it has the same overlapping text content.
If you just want to show a single piece of text, then pass that string to your showText function (e.g., showText("hello")). Then, since you’re just creating individual elements, just selection.append them rather than using a data-join. You only need the data-join when you’re creating (or updating or removing) a variable number of elements based on data; in this case it looks like you’re trying to just create a single element.
I made a simulation of 10000 times and want to view part of simulation between 5000-5200. I am able to view it with the code below, but the x-axis says 0-250. I want the x-axis to display the exact figure of 5000-5200. Also there seems to be a small gap at the end of the figure as the axis runs up to 250 for some reason. I just want to view the figure in for this set time with the x-axis showing the exact labels and without the gap at the end.
Thanks
N=10000;%Number of simulation
P=0.02;
Q = zeros(N,1); %current value of queue
X=zeros(N,1);%simulation data
Ci=0;
L=0.9;
Bu=zeros(N,1);
Bs=30;
Bd1=50;
Bd2=270;
Ti=0;
for Ti=2:N
U=rand(1);
a=log10(U);
b=log10(1-P);
c=(a/b);
d=1+c;
X(Ti)=round(d);
Ci=Ci+1;
if X(Ti)< (L)*(Bs)
Bu(Ti)=Bs;
else if X(Ti) < (L)*(Bs+Bd1)
Bu(Ti)=Bs+Bd1;
else
Bu(Ti)=Bs+Bd1+Bd2;
end
end
Ti=Ti+1;
end
plot(X(5000:5200,1),'r');
set (gca,'ylim',[0 400]);
hold on;
plot(Bu(5000:5200,1),'b');
set (gca,'ylim',[0 400]);
hold off
Plot expects two inputs, the first depicting the horizontal axis and the second depicting the vertical axis. When you do not supply two inputs, then it computes the length of the single input (in this case that length is 5200-5000 = 200), and it just uses 1 through that length (1:200 in this case) as if it is the values for the horizontal axis variable.
I think you want to issue the command:
plot(5000:5200, X(5000:5200,1), 'r')
Often Matlab will adjust plot axes for better default views, so it's probably showing the axis out to the index 250 just by virtue of some default plotting convention. You can similarly use set(gca, 'xlim', [5000 5200]) if you wish.