d3.js Sankey diagram: rectangles fill color - d3.js

So I am playing around with the d3.js Sankey diagram.
In this example (pictured above) color is defined using
var color = d3.scale.category20();
For each node there is a rectangle, and that rectangle is filled by altering the style:
.style("fill", function(d) {
return d.color = color(d.name.replace(/ .*/, ""));
})
I'm looking for suggestions on using custom colors. If I wanted to use only say 6 colors, but have the node rectangle colors chosen based on a value in the .json file.
For example, lets say I wanted to show a snakey chart of teams in the NFL. The colours each represent which division the teams play in. So if they move to a different division, the color changes. And the nodes are created for every season. Something along those lines.
So is it possible to run the
node.append("rect")
.attr("height", function(d) { return d.dy; })
.attr("width", sankey.nodeWidth())
.style("fill", function(d) {
return d.color = color(d.name.replace(/ .*/, ""));
})
.style("stroke", function(d) {
return d3.rgb(d.color).darker(2);
})
.append("title")
.text(function(d) { return d.name + "\n" + format(d.value); });
with the color based on a value in the json file? I am thinking just an if statement, but is there an easier way? Could I just include the hex color code in the json?

Alternatively, you could map the colors to the division explicitly with a d3 ordinal scale as mentioned in the documentation. See Colorbrewer at the bottom.
var color = d3.scale.ordinal()
.domain(["foo", "bar", "baz"])
.range(["#fff","#000","#333"]);
and then
.attr("fill", function(d) { return color(d.division); });

Sounds like you want to include the colour in the JSON in this case. You can include it in any way that the browser recognises, e.g. as a name ("white") or hex ("#fff"). See the SVG spec for a full list of supported colour specifications.

Replace const color = d3.scaleOrdinal(d3.schemeCategory20); with:
const color = d3.scaleOrdinal()
.domain(["Crude oil","Natural gas",...])
.range(["#FD3E35","#FFCB06",...]);
And stay with:
.style('fill', (d,i) => {
d.color = color(d.name.replace(/ .*/, ''));
return d.color;})

Related

Choropleth map scale and legend

Let me preface this by saying I am brand new to D3.js and coding in general. I am an infographic artist and I've been using QGIS to generate maps, but am trying to use D3.js to generate a choropleth map for a story about Opioid deaths. Basically I am trying to recreate this map.
map from the Economist
I have tried to start by using this map by Mike Bostock and changing some of the parameters but am getting stuck with the color range and scale. The measurement is 1 per 100,000 population. I have a domain that starts at 1.543385761 and ends at 131.0814217.
The code I'm struggling with is around the scale input and output:
var x = d3.scaleLinear()
.domain([0, 132])
.rangeRound([600, 860]);
var color = d3.scaleThreshold()
.domain(d3.range(2, 10))
.range(d3.schemeBlues[9]);
var g = svg.append("g")
.attr("class", "key")
.attr("transform", "translate(0, 40)");
g.selectAll("rect")
.data(color.range().map(function(d) {
d = color.invertExtent(d);
if (d[0] == null) d[0] = x.domain()[0];
if (d[1] == null) d[1] = x.domain()[1];
return d;
}))
.enter().append("rect")
.attr("height", 8)
.attr("x", function(d) { return x(d[0]); })
.attr("width", function(d) { return x(d[1]) - x(d[0]); })
.attr("fill", function(d) { return color(d[0]); });
I can see that I need some bit of code that will define everything 25 and over as the darkest color. Not even sure I want that to be my final legend but I'd love to know how to reproduce that. I am shocked I was able to get this far but feel a bit lost right now. thank you in advance!
Let's examine your scale:
var color = d3.scaleThreshold()
.domain(d3.range(2, 10))
.range(d3.schemeBlues[9]);
Your domain is an array of created like so:
d3.range(2,10) // [2,3,4,5,6,7,8,9]
These are your thresholds, colors will be mapped based on values that are less than or equal to 2, more than two up to three, more than three and up to four .... and over 9. This domain is mapped to nine values defined in the range:
d3.schemeBlues[9] // ["#f7fbff", "#deebf7", "#c6dbef", "#9ecae1", #6baed6", #4292c6", "#2171b5", "#08519c", "#08306b"]
To set the thresholds for those colors so that values over 25 are one color, define the domain with array that has the appropriate threshold(s):
.domain([2,3,4,5,6,7,8,25]);
In the snippet below, this domain is applied. Rectangles have colors dependent on their location, all rectangles after the 25th (count left to right then line by line) one will be of one color.
var color = d3.scaleThreshold()
.domain([2,3,4,5,6,7,8,25])
.range(d3.schemeBlues[9]);
var svg = d3.select("body")
.append("svg")
.attr("width",500)
.attr("height",500);
var rects = svg.selectAll("rect")
.data(d3.range(100))
.enter()
.append("rect")
.attr("width",15)
.attr("height", 15)
.attr("y", function(d,i) { return Math.floor(i / 10) * 20 + 10 })
.attr("x", function(d,i) { return i % 10 * 20 })
.attr("fill", function(d) { return color(d); })
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.5.0/d3.min.js"></script>
<script src="https://d3js.org/d3-scale-chromatic.v1.min.js"></script>

piechart over a map point using d3.js

I want to draw a pie chart for every point on the map instead of a circle.
The map and the points are displaying well but the pie chart is not showing over the map points. There is no error also. I can see the added pie chart code inside map also.
Below is the code snippet .
var w = 600;
var h = 600;
var bounds = [[78,30], [87, 8]]; // rough extents of India
var proj = d3.geo.mercator()
.scale(800)
.translate([w/2,h/2])
.rotate([(bounds[0][0] + bounds[1][0]) / -2,
(bounds[0][1] + bounds[1][1]) / -2]); // rotate the project to bring India into view.
var path = d3.geo.path().projection(proj);
var map = d3.select("#chart").append("svg:svg")
.attr("width", w)
.attr("height", h);
var india = map.append("svg:g")
.attr("id", "india");
var gDataPoints = map.append("g"); // appended second
d3.json("data/states.json", function(json) {
india.selectAll("path")
.data(json.features)
.enter().append("path")
.attr("d", path);
});
d3.csv("data/water.csv", function(csv) {
console.log(JSON.stringify(csv))
gDataPoints.selectAll("circle")
.data(csv)
.enter()
.append("circle")
.attr("id", function (d,i) {
return "chart"+i;
})
.attr("cx", function (d) {
return proj([d.lon, d.lat])[0];
})
.attr("cy", function (d) {
return proj([d.lon, d.lat])[1];
})
.attr("r", function (d) {
return 3;
})
.each(function (d,i) {
barchart("chart"+i);
})
.style("fill", "red")
//.style("opacity", 1);
});
function barchart(id){
var data=[15,30,35,20];
var radius=30;
var color=d3.scale.category10()
var svg1=d3.select("#"+id)
.append("svg").attr('width',100).attr('height',100);
var group=svg1.append('g').attr("transform","translate(" + radius + "," + radius + ")");
var arc=d3.svg.arc()
.innerRadius('0')
.outerRadius(radius);
var pie=d3.layout.pie()
.value(function(d){
return d;
});
var arcs=group.selectAll(".arc")
.data(pie(data))
.enter()
.append('g')
.attr('class','arc')
arcs.append('path')
.attr('d',arc)
.attr("fill",function(d,i){
return color(d.data);
//return colors[i]
});
}
water.csv:
lon,lat,quality,complaints
80.06,20.07,4,17
72.822,18.968,2,62
77.216,28.613,5,49
92.79,87.208,4,3
87.208,21.813,1,12
77.589,12.987,2,54
16.320,75.724,4,7
In testing your code I was unable to see the pie charts rendering, at all. But, I believe I still have a solution for you.
You do not need a separate pie chart function to call on each point. I'm sure that there are a diversity of opinions on this, but d3 questions on Stack Overflow often invoke extra functions that lengthen code while under-utilizing d3's strengths and built in functionality.
Why do I feel this way in this case? It is hard to preserve the link between data bound to svg objects and your pie chart function, which is why you have to pass the id of the point to your function. This will be compounded if you want to have pie chart data in your csv itself.
With d3's databinding and selections, you can do everything you need with much simpler code. It took me some time to get the hang of how to do this, but it does make life easier once you get the hang of it.
Note: I apologize, I ported the code you've posted to d3v4, but I've included a link to the d3v3 code below, as well as d3v4, though in the snippets the only apparent change may be from color(i) to color[i]
In this case, rather than calling a function to append pie charts to each circle element with selection.each(), we can append a g element instead and then append elements directly to each g with selections.
Also, to make life easier, if we initially append each g element with a transform, we can use relative measurements to place items in each g, rather than finding out the absolute svg coordinates we would need otherwise.
d3.csv("water.csv", function(error, water) {
// Append one g element for each row in the csv and bind data to it:
var points = gDataPoints.selectAll("g")
.data(water)
.enter()
.append("g")
.attr("transform",function(d) { return "translate("+projection([d.lon,d.lat])+")" })
.attr("id", function (d,i) { return "chart"+i; })
.append("g").attr("class","pies");
// Add a circle to it if needed
points.append("circle")
.attr("r", 3)
.style("fill", "red");
// Select each g element we created, and fill it with pie chart:
var pies = points.selectAll(".pies")
.data(pie([0,15,30,35,20]))
.enter()
.append('g')
.attr('class','arc');
pies.append("path")
.attr('d',arc)
.attr("fill",function(d,i){
return color[i];
});
});
Now, what if we wanted to show data from the csv for each pie chart, and perhaps add a label. This is now done quite easily. In the csv, if there was a column labelled data, with values separated by a dash, and a column named label, we could easily adjust our code to show this new data:
d3.csv("water.csv", function(error, water) {
var points = gDataPoints.selectAll("g")
.data(water)
.enter()
.append("g")
.attr("transform",function(d) { return "translate("+projection([d.lon,d.lat])+")" })
.attr("class","pies")
points.append("text")
.attr("y", -radius - 5)
.text(function(d) { return d.label })
.style('text-anchor','middle');
var pies = points.selectAll(".pies")
.data(function(d) { return pie(d.data.split(['-'])); })
.enter()
.append('g')
.attr('class','arc');
pies.append("path")
.attr('d',arc)
.attr("fill",function(d,i){
return color[i];
});
});
The data we want to display is already bound to the initial g that we created for each row in the csv. Now all we have to do is append the elements we want to display and choose what properties of the bound data we want to show.
The result in this case looks like:
I've posted examples in v3 and v4 to show a potential implementation that follows the above approach for the pie charts:
With one static data array for all pie charts as in the example: v4 and v3
And by pulling data from the csv to display: v4 and v3

Can't fill circle background with color threshold

I try to display circles on a map for a particular dataset. The dataset provides where to center the circle. The dataset contains an identifier (attribute name), a year (attribute year) and a value (attribute value)
I would like to display two things at this level:
The radius of the circle according to the value
The background color (fill) of the circle according to the year and using threshold
A tooltip when the circle is clicked.
Here is the code I use:
var circle = d3.geo.circle();
var color = d3.scale.threshold()
.domain([ 1800, 1850, 1900, 1950, 2000, 2050 ])
.range("#f2f0f7", "#dadaeb", "#bcbddc", "#9e9ac8", "#756bb1", "#54278f");
var elements = layerElement.selectAll('circle')
.data(data)
.enter()
.append('path')
.attr('id', function(d) {
return d.name;
});
elements
.datum(function(d) {
return circle
.origin(origin({d: d}))
.angle(radius({d: d}))();
})
.attr('class', 'point')
.attr('d', path)
.style('fill', function(d) {
return color(d.year);
})
.style('opacity', '0.6');
elements.on('click', function(d) {
(...)
});
I set an identifier to each circle. I see them within the in-memory SVG DOM:
<path id="Hoba"
class="point"
d="M488.55415440889976,286.8579825670507L488.45185788883936,284.8328597859807L488.56757478032006,282.785303550314L488.90003726486356,280.73774731464727L489.445602813917,278.71262453357724L490.1982940971579,276.7321228760774L491.14986447137636,274.8179411327541L492.2898883324236,272.99105147935524L493.6058753403125,271.2714697012249L495.0834072659968,269.6780358961697L496.7062959605052,268.2282080584055L498.45676071568937,266.9378708051187L500.3156230733832,265.82116134127676L502.2625169486039,264.890314569452...L508.2862800372698,302.266499816963L506.206659850514,302.3738076922315L504.15052774957604,302.26649981696306L502.14041114802717,301.9457518786948L500.19833330399786,301.41507805895924L498.3455720287532,300.680292531176L496.6024265625401,299.74944575935126L494.9879951718629,298.63273629550935L493.5199659048794,297.34239904222255L492.2144227974436,295.8925712044583L491.08566965304294,294.2991373994032L490.1460733273343,292.5795556212728L489.4059282342853,290.752665967874L488.8733435584207,288.8384842245506Z"
style="fill: yellow; opacity: 0.75;">
My problems are:
Within the function attr, the first parameter corresponds to the selected shape but there is no identifier in it. Here is the content I get:
{"type":"Polygon","coordinates":[[[5.279833759995999,-21.628058088269754],(...)[5.525725679844768,-22.85403683844725],[5.279833759996005,-21.628058088269807]]]}
So I can't get the corresponding value to apply a background color
I have the same problem when clicking the element
My question is how to get the identifier for the selected element (circle shape in my case).
Thanks very much for your help!
Thierry
Your call to datum is generating a path from each data item but throwing away the rest of it, including the properties. If you want to keep the properties, nest the object that it generates:
.datum(function(d) {
return {
circle: circle
.origin(origin({d: d}))
.angle(radius({d: d}))(),
d: d
};
})
And then the rest of your calls will follow: like
.attr('d', function(d) { return path(d.circle); })
And
.style('fill', function(d) {
return color(d.d.year);
})

Resizing SVG for precise printing

I'm working on a little project to print scaled down archery targets for practice at shorter range indoors. For example, the target face shown here:
...is 16cm in diameter at full size for 20 yards, but needs to be printed at half that size for practice at 10 yards. There are many different styles of target faces, and I'd like to support as many as possible. I have D3 working to pull the relevant sizes from a CSV file.
I'm specifying the sizes of the elements of the SVG in centimeters whenever possible. Is it possible to use D3 to generate a PDF that can be printed at a specific size?
Here's my code that loads the CSV and generates the SVG.
var dataset;
var w = "16cm";
var h = "16cm";
d3.csv("./data/nfaa5spot.csv", function(error, data) {
if (error) {
console.log(error);
} else {
console.log(data);
// Hand data off to global var for processing
dataset = data;
var svg = d3.select("body")
.append("svg")
.attr("width", w)
.attr("height", h)
.attr("viewBox", "-400,-400,1700,1700");
var circles = svg.selectAll("circle")
.data(dataset)
.enter()
.append("circle")
.attr({
cx: function(d) { return d["cx"]; },
cy: function(d) { return d["cy"]; },
r: function(d) { return d["r"]; }
})
.style("fill", function(d) { return d["fill"]; })
.style("stroke", function(d) { return d["stroke"]; })
.style("stroke-width", function(d) { return d["stroke-width"]; });
}
});
Here are the contents of the relevant CSV file:
r,cx,cy,fill,stroke,stroke-width
16cm,8cm,8cm,#164687,#164687,0
12cm,8cm,8cm,#164687,white,3
8cm,8cm,8cm,white,white,0
4cm,8cm,8cm,white,#164687,3
Resizing is just first part. I'm also working on drawing additional lines on the target face to compensate for arrow shaft diameter at shorter range. Fun project, and a good intro to working with D3.

d3.js Color coding grid based on data from a csv file

I built a grid of squares based on the example given in http://bl.ocks.org/bunkat/2605010. Now i am trying to color code each of the cells in the grid based on the data from csv file. Say for example, i have a csv file with data as
cell, col1
1,2
2,3
3,2
4,1
cells are colored based on data in col1. Like cell 1 colored with blue, cell 2 colored with green, cell 3 colored again with blue, cell 4 colored with red.
I have been trying something like this, but it doesn't work. Please help?
d3.text("frame.csv", function(datasetText) {
var parsedCSV = d3.csv.parseRows(datasetText);
var col = row.selectAll(".cell")
.data(function (d) { return d; })
.enter().append("svg:rect")
.attr("class", "cell")
.attr("x", function(d) { return d.x; })
.attr("y", function(d) { return d.y; })
.attr("width", function(d) { return d.width; })
.attr("height", function(d) { return d.height; })
.style("fill", function(d) { return color(parsedCSV[d].col1); })
.style("fill", '#FFF')
.style("stroke", '#555');
});
There is a 'fill' attribute that you can use to set the fill color of the item. Like other d3 functions, you can pass it either a value, or a function which returns the value. It sounds like you would want to use a function which will determine what colour you want, then return that value. Note that you will have to return it as a string (so wrapped in quotes) as either '#660066' or 'rgb(166,0,166)'. You could also use rgba if you wish.
After this it is just a matter of writing your function to return the right colour, which I can't really help you with as I don't know what you want.
Also this may be a duplicate of d3js fill color.
I found my mistake. I had to use d3.csv.parse(string) instead of d3.csv.parseRows(string[, accessor]) function since my csv file contained column names. Thanks for the help. Appreciate it.

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