Develop Reference

How to update data in a diverging stacked bar-chart d3js

I've made a plunker that updates data from one csv file to another, the yaxis updates accordingly but the rectangles don't.
The .attr("height", function(d) { return Math.abs(y(d[0])) - y(d[1]); }); portion of the code still has the old data from the previous file (I'm guessing).
I'm guessing this is because I haven't declared .data(series) in the updateData() function, I remember doing something like this in another chart
g.selectAll(".bar").data(series).transition()
etc...
but this doesn't work in this chart.
I can't figure it out, any help is appreciated!

The problem was that you didn't join the new data to existing bars.
To make this work well, you will want to specify a key for category of data when you join the series to the g elements to ensure consistency (although I notice that category-1 is positive in the first dataset, and negative in the second, but this is test data i guess)
Here's the updated plunkr (https://plnkr.co/edit/EoEvVWiTji7y5V3SQTKJ?p=info), with the relevant code highlighted below:
g.append("g")
.selectAll("g")
.data(series, function(d){ return d.key }) //add function to assign a key
.enter().append("g")
.attr("class", "bars") //so its easy to select later on
//etc
...
function updateData() {
d3.csv("data2.csv", type, function(error, data) {
///etc
let bars = d3.selectAll(".bars") //select the g elements
bars.data(series, function(d){ return d.key }) //join the new data
.selectAll(".bar")
.data(function(d) { return d; })
.transition()
.duration(750)
.attr("y", function(d) { return y(d[1]); })
.attr("height", function(d) { return Math.abs(y(d[0])) - y(d[1]); });

How to update the scattergraph?

I have this table and chart with scattergraph:
https://jsfiddle.net/horacebury/bygscx8b/6/
And I'm trying to update the positions of the scatter dots when the values in the second table column change.
Based on this SO I thought I could just use a single line (as I'm not changing the number of points, just their positions):
https://stackoverflow.com/a/16071155/71376
However, this code:
svg.selectAll("circle")
.data(data)
.transition()
.duration(1000)
.attr("cx", function(d) {
return xScale(d[0]);
})
.attr("cy", function(d) {
return yScale(d[1]);
});
Is giving me this error:
Uncaught TypeError: svg.selectAll(...).data is not a function

The primary issue is that:
svg.selectAll("circle") is not a typical selection as you have redefined svg to be a transition rather than a generic selection:
var svg = d3.select("#chart").transition();
Any selection using this svg variable will return a transition (from the API documentation), for example with transition.selectAll():
For each selected element, selects all descendant elements that match
the specified selector string, if any, and returns a transition on the
resulting selection.
For transitions, the .data method is not available.
If you use d3.selectAll('circle') you will have more success. Alternatively, you could drop the .transition() when you define svg and apply it only to individual elements:
var svg = d3.select('#chart');
svg.select(".line").transition()
.duration(1000).attr("d", valueline(data));
...
Here is an updated fiddle taking the latter approach.
Also, for your update transition you might want to change scale and values you are using to get your new x,y values (to match your variable names):
//Update all circles
svg.selectAll("circle")
.data(data)
.transition()
.duration(1000)
.attr("cx", function(d) {
return x(d.date);
})
.attr("cy", function(d) {
return y(d.close);
});
}

Create Path Between Initial Child Nodes - D3 Tree Layout

I am using the D3 Collapsible Tree Layout and would like to create a path that begins at the first child node and travels all the way to the last initial child node, while mainlining it's position when the graph is scaled/updated. Basically this is what I'm going for
I've tried this so far:
var nodes = tree.nodes(root).reverse();
/**
* transition logic, etc
**/
var rootNodes = [ nodes[0], nodes[1] ]; //will use first 2 nodes as an example (will want to include all initial root nodes)
var lineFunction = d3.svg.line('step')
.x(function(d) { return d.y; })
.y(function(d) { return d.x; })
.interpolate("linear");
var lineGraph = vis.append("path")
.attr("d", lineFunction(nodes))
.attr("stroke", "#ccc")
.attr("stroke-width", "1.5")
.attr("fill", "none");
}
However I'm not sure how to get it to transition within the update() function properly, also it creates extra paths under the root nodes and ends up looking like this:
Any ideas?
UPDATE: If I grab the root of my data array, I can keep my new paths within the first child nodes of my tree
root = json;//JSON Object returned from my program
//...
var rootNodes = [ root.children[0], root.children[1] ];

multiple circles / lines using d3.js

I have a d3.js problem and have struggled with this for a while and just can not seem to solve it. I believe it is pretty easy, but am missing something very basic.
Specifically, I have the following code, which generates a line and 2 circles for the 1st entry in the JSON - I have 'hardcoded' it for the first entry.
I'd like to now add the 2nd and 3rd entries of the JSON file to the graph and have control over line and circle colors and then generalize the code.
From reading the documentation and StackOverflow, it seems like the proper approach is to use nesting, but I can't seem to make it work?
The code is on jsfiddle at the following URL and the javascript is below.
http://jsfiddle.net/GVmVk/
// INPUT
dataset2 =
[
{
movie : "test",
results :
[
{ week: "20130101", revenue: "60"},
{ week: "20130201", revenue: "80"}
]
},
{
movie : "beta",
results :
[
{ week: "20130101", revenue: "40"},
{ week: "20130201", revenue: "50"}
]
},
{
movie : "gamm",
results :
[
{ week: "20130101", revenue: "10"},
{ week: "20130201", revenue: "20"}
]
}
];
console.log("1");
var parseDate = d3.time.format("%Y%m%d").parse;
var lineFunction = d3.svg.line()
.x(function(d) { return xScale(parseDate(String(d.week))); })
.y(function(d) { return yScale(d.revenue); })
.interpolate("linear");
console.log("2");
//SVG Width and height
var w = 750;
var h = 250;
//X SCALE AND AXIS STUFF
//var xMin = 0;
//var xMax = 1000;
var xScale = d3.time.scale()
.domain([parseDate("20130101"),parseDate("20131231")])
.range([0, w]);
console.log(parseDate("20130101"));
console.log("3");
var xAxis = d3.svg.axis()
.scale(xScale)
.orient("bottom");
console.log("4S");
//Y SCALE AND AXIS STUFF
var yScale = d3.scale.linear()
.domain([0, 100])
.range([h, 0]);
var yAxis = d3.svg.axis()
.scale(yScale)
.orient("left")
.ticks(5);
//Create SVG element
var svg = d3.select("body")
.append("svg")
.attr("width", w)
.attr("height", h);
console.log("4S1");
//CREATE X-AXIS
svg.append("g")
.attr("class", "axis")
.attr("transform", "translate(0," + (h - 30) + ")")
.call(xAxis);
//Create Y axis
svg.append("g")
.attr("class", "axis")
.attr("transform", "translate(" + 25 + ",0)")
.call(yAxis);
svg.selectAll("circle")
.data(dataset2[0].results)
.enter()
.append("circle")
.attr("cx", function(d) {
// console.log(d[0]);
console.log(parseDate(d.week));
return xScale(parseDate(d.week));
})
.attr("cy", function (d) {
return yScale(d.revenue);
})
.attr("r", 3);
//create line
var lineGraph = svg.append("path")
.attr("d", lineFunction(dataset2[0].results))
.attr("class", "line");

The word "nesting" comes up in two contexts in d3 -- creating nested data arrays with d3.nest, and using nested data to create nested selections.
Your data is already in the correct format for a nested selection -- an array of objects, each of which has a sub-array of individual data points. So you don't need to worry about manipulating the data, you just need to go straight to joining your data to your elements in nested d3 selections:
I'm going to take you through it quickly, but the following tutorials will be good reference for the future:
Thinking with Joins
Nested Selections
How Selections Work
On to your example: you have a top-level data structure that is an array of movie objects, each of which contains a sub-array of weekly revenue values. The first thing you need to decide is what type of elements you want associated with each level of data. You're drawing a line and a set of circles for the data in the sub-array, but aren't currently adding anything for the top-level array objects (the movies). You need to add something for them in order for nested selections to work, and it needs to be something that can contain your line and circle. In SVG, that's almost always going to be a <g> (grouping) element.
To efficiently create one <g> element for every object in your data array -- and to attach the data objects to the elements for future reference -- you create an empty selection, join your data to it, then use the enter() method of the data join selection to add elements for each data object that didn't match an element. In this case, since we don't have any elements to start, all the data objects will be in the enter() selection. However, the same pattern also works when updating some of the data.
var movies = svg //start with your svg selection,
//it will become the parent to the entering <g> elements
.selectAll("g.movie") //select all <g> elements with class "movie"
//that are children of the <svg> element
//contained in the `svg` selection
//this selection will currently be empty
.data( dataset2 ); //join the selection to a data array
//each object in the array will be associated with
//an element in the selection, if those elements exist
//This data-joined selection is now saved as `movies`
movies.enter() //create a selection for the data objects that didn't match elements
.append("g") //add a new <g> element for each data object
.attr("class", "movie") //set it's class to match our selection criteria
//for each movie group, we're going to add *one* line (<path> element),
//and then a create subselection for the circles
.append("path") //add a <path> within *each* new movie <g> element
//the path will *inherit* the data from the <g> element
.attr("class", "line"); //set the class for your CSS
var lineGraph = movies.select("path.line")
//All the entered elements are now available within the movies selection
//(along with any existing elements that we were updating).
//Using select("path") selects the first (and only) path within the group
//regardless of whether we just created it or are updating it.
.attr("d", function(d){ return lineFunction(d.results); });
//the "d" attribute of a path describes its shape;
//the lineFunction creates a "d" definition based on a data array.
//If the data object attached to the path had *only* been the d.results array
//we could have just done .attr("d", lineFunction), since d3
//automatically passes the data object to any function given as the value
//of an .attr(name, value) command. Instead, we needed to create an
//anonymous function to accept the data object and extract the sub-array.
var circles = movies.selectAll("circle")
//there will be multiple circles for each movie group, so we need a
//sub-selection, created with `.selectAll`.
//again, this selection will initially be empty.
.data( function(d) {return d.results; });
//for the circles, we define the data as a function
//The function will be called once for each *movie* element,
//and passed the movie element's data object.
//The resulting array will be assigned to circles within that particular
//movie element (or to an `enter()` selection, if the circles don't exist).
circles.enter() //get the data objects that don't have matching <circle> elements
.append("circle") //create a circle for each
//the circles will be added to the appropriate "g.movie"
//because of the nested selection structure
.attr("r", 3); //the radius doesn't depend on the data,
//so you can set it here, when the circle is created,
//the same as you would set a class.
circles //for attributes that depend on the data, they are set on the entire
//selection (including updating elements), after having created the
//newly entered circles.
.attr("cx", function(d) { return xScale( parseDate(d.week) ); })
.attr("cy", function(d) { return yScale( d.revenue ); });
Live version with the rest of your code: http://jsfiddle.net/GVmVk/3/
You'll need to adjust the domain of your x-scale so that the first data points aren't cut off, and you'll need to decide how you want to use your movie title property, but that should get you going.

Yes indeed, nested selection are the way to go for the circles, although you don't need them for the paths:
svg.selectAll("g.circle")
.data(dataset2)
.enter()
.append("g")
.attr("class", "circle")
.selectAll("circle")
.data(function(d) { return d.results; })
.enter()
.append("circle")
.attr("cx", function(d) {
// console.log(d[0]);
console.log(parseDate(d.week));
return xScale(parseDate(d.week));
})
.attr("cy", function (d) {
return yScale(d.revenue);
})
.attr("r", 3);
//create line
var lineGraph = svg.selectAll("path.line")
.data(dataset2).enter().append("path")
.attr("d", function(d) { return lineFunction(d.results); })
.attr("class", "line");
Complete example here.

Conditionally build group in d3

I am trying to build a graph using the force layout in D3. I would like to build different looking nodes depending on the data. Currently all nodes have a category and a name. So I draw an svg:g consisting of two rect and two text elements.
My code currently looks something like this:
// nodes are in the form: { group: 'string', name: 'string2' }
this.node = this.node.data(this.node, function(d) { return d.id; });
var g = this.node.enter().
append('svg:g').
attr('transform', function(d) { return 'translate('+ d.x +','+ d.y +')'; });
g.append('svg:rect').attr('h', 20).attr('w', 100);
g.append('svg:rect').attr('y', 20).attr('h', 20).attr('w', 100);
g.append('svg:text').text(function(d) { d.group; });
g.append('svg:text').attr('y', 20).text(function(d) { d.name; });
If the node doesn't have a name, however, I'd like to supress the creation of the second rect and text. Logically, if it wasn't for the implicit iterator in d3 I'd be doing something like:
var g = this.node.enter().
append('svg:g').
attr('transform', function(d) { return 'translate('+ d.x +','+ d.y +')'; });
g.append('svg:rect').attr('h', 20).attr('w', 100);
g.append('svg:text').text(function(d) { d.group; });
// unfortunately 'd' isn't defined out here.
// EDIT: based on comment from the answer below; the conditional should
// be for the text and the related rectangle.
if(d.name) {
g.append('svg:rect').attr('y', 20).attr('h', 20).attr('w', 100);
g.append('svg:text').attr('y', 20).text(function(d) { d.name; });
}

You could use an each call on your g selection to decide whether or not to add the label.
g.each(function(d) {
if (d.name){
var thisGroup = d3.select(this);
thisGroup.append("text")
.text(d.group);
thisGroup.append("text")
.attr("y", 20)
.text(d.name);
});
However, be aware that this structure could get confusing if you're going to be updating the data.
If you want to be able to update neatly, I would recommend doing a nested selection:
var labels = g.selectAll("text")
.data(function(d){ d.name? [d.group, d.name]:[]; });
labels.enter().append("text");
labels.exit().remove();
labels.text(function(d){return d;})
.attr("y", function(d,i){return i*20;});
The data-join function tests the parent's data object, and based on it either passes an array containing the two values you want to use for the label text, or an empty array. If it passes the empty array, then no labels are created; otherwise, each label has it's text set by the value in the array and it's vertical position set by the index.