D3 graphing selective portions of data set - javascript

I have a large time series data set I need to graph, and am trying to use D3 to do it. I plan to have my graph have the x-axis be time, and allow for movement of the graph in the x direction. I want to have the graph only load/display the points that exist in the current time range on the screen.
For example, if my dataset has times 1-100, but the graph starts out with times 1-10 shown, the graph should only graph points 1-10. Then the user may move to the right and see times 5-15 and the graph should update accordingly.
Can anyone explain to me how this might be done via d3? I am having a hard time bridging the understanding from an entire data set being loaded in at once and graphed immediately to selective graphing of subsets of the data.

I think you are looking for the selection.filter() function. For example you can have:
var allNodes = vis.selectAll("Nodes").data(data.nodes);
var validNodes = allNodes.filter(function(d){return (d.time>1 && d.time <10)});
//use normal graph functions on validNodes.
You can also apply filter directly on the array of nodes.

Related

d3 - Show data nodes one at a time through transitional delays

Basically I have a line graph with several data points. I want to display these data points (or circles) one after the other as the line in which the nodes is drawn. However, I can't figure out how to chain it so that they only display one at a time. Instead, they're all showing at once. Any thoughts on the issue? This is my code that shows them:
d3.selectAll('circle').each(function(d, i) {
d3.select(this).transition().delay(3000).duration(2500).style('opacity', 1);
});

D3 parcoords axis scale not updating correctly

I'm using the d3 parcoords library. When I modify data plotted in a parallel coordinates chart, and reload the chart, the scale of the axis isn't refreshed.
I tried calling .autoscale(), but if I call it before .render(), it has no effect, and if I call it after .render(), then no polylines are drawn anymore.
$("#example").html(""); //to make sure "ghost" axes are removed
parcoords = d3.parcoords()("#example")
.data(parsedData)
.createAxes()
.brushMode("1D-axes")
.reorderable()//;
.detectDimensions()
.dimensions(dimensionObj)
.autoscale() //no visible effect if placed here
.render()
.updateAxes();
Not sure if this is related (although the issue started at the same time), I started specifying an order for the dimensions. To do this, instead of using an array containing the axes (dimensionArray), I use a JS object dimensionObj containing numbered "index" keys, as follows:
//dimensionArray = ["axis1", "axis2", "axis3", "axis4"]; //orderless array
//Default axes to display with predefined ordering
dimensionObj = {
"axis1": {index:0},
"axis2": {index:1},
"axis3": {index:2},
"axis4": {index:3}
}
For illustration purposes, the following screenshots show how on the top image, the scales are properly set, but on the second (updated) chart, some new polylines are going to 0 on the 1st and 3rd axis, but the scale isn't updated so lines go out of range.
Is there a simple way to refresh the axis scales when reloading a chart? Is it possible that using the JS object in .dimensions() is creating some conflicts with the underlying scale function?
Found what was causing this behaviour: an if statement in d3.parcoords.js pc.autoscale function which was only resetting scales if the yscale was not previously defined. Essentially I edited the if statement from original:
d3.keys(__.dimensions).forEach(function(k) {
if (!__.dimensions[k].yscale){
__.dimensions[k].yscale = defaultScales[__.dimensions[k].type](k);
}
});
to this (of course the if statement could be dropped altogether, I simply kept it in this form in case I need to revert to original version later for any reason):
d3.keys(__.dimensions).forEach(function(k) {
if (!__.dimensions[k].yscale || __.dimensions[k].yscale){
__.dimensions[k].yscale = defaultScales[__.dimensions[k].type](k);
}
});

Rickshaw/d3.js - equally-spaced series

I have a graph made with rickshaw (line graph).
The graph is working fine but unreadable. The time(x) data for the graph is irregular.
e.g:
{"x":1387669802,"y":1256},
{"x":1387669803,"y":1273},
{"x":1387669804,"y":1256},
{"x":1387669805,"y":1248},
{"x":1387669820,"y":1281},
...huge time gap...
{"x":1370122812,"y":1281},
{"x":1370122813,"y":1236},
{"x":1370122852,"y":1252},
{"x":1370122822,"y":1281}
there are many gaps between a little series of data. sometimes big gaps, sometimes small gaps. What I try is to set a fix distance between two data points.
Last time i worked with morris.js. There was a option named parseTime which does exactly that. treating the data as an equally-spaced series.
http://www.oesmith.co.uk/morris.js/lines.html
Any idea how to do that with rickshaw/d3?
Regards

d3.v3 scatterplot with all circles the same radius

Every example I have found shows all of the scatter plot points to be of random radii. Is it possible to have them all the same size? If I try to statically set the radius all of the circles will be very small (I'm assuming the default radius). However, if I use Math.random() as in most examples there are circles large and small. I want all the circles to be large. Is there a way to do that? Here's the code snippet forming the graph data using Math.random() (this works fine for some reason):
function scatterData(xData, yData)
{
var data = [];
for (var i = 0; i < seismoNames.length; i++)
{
data.push({
key: seismoNames[i],
values: []
});
var xVals=""+xData[i];
xVals=xVals.split(",");
var yVals=""+yData[i];
yVals=yVals.split(",");
for (var j = 0; j < xVals.length; j++)
{
data[i].values.push({
x: xVals[j],
y: yVals[j],
size: Math.random()
});
}
}
return data;
}
Math.random() spits out values between 0 and 1 such as 0.164259538891095 and 0.9842195005008699. I have tried putting these as static values in the 'size' attribute, but no matter what the circles are always really small. Is there something I'm missing?
Update: The NVD3 API has changed, and now uses pointSize, pointSizeDomain, etc. instead of just size. The rest of the logic for exploring the current API without complete documentation still applies.
For NVD3 charts, the idea is that all adjustments you make can be done by calling methods on the chart function itself (or its public components) before calling that function to draw the chart in a specific container element.
For example, in the example you linked too, the chart function was initialized like this:
var chart = nv.models.scatterChart()
.showDistX(true)
.showDistY(true)
.color(d3.scale.category10().range());
chart.xAxis.tickFormat(d3.format('.02f'));
chart.yAxis.tickFormat(d3.format('.02f'));
The .showDistX() and .showDistY() turn on the tick-mark distribution in the axes; .color() sets the series of colours you want to use for the different categories. The next too lines access the default axis objects within the chart and set the number format to be a two-digit decimal. You can play around with these options by clicking on the scatterplot option from the "Live Code" page.
Unfortunately, the makers of the NVD3 charts don't have a complete documentation available yet describing all the other options you can set for each chart. However, you can use the javascript itself to let you find out what methods are available.
Inspecting a NVD3.js chart object to determine options
Open up a web page that loads the d3 and nvd3 library. The live code page on their website works fine. Then open up your developer's console command line (this will depend on your browser, search your help pages if you don't know how yet). Now, create a new nvd3 scatter chart function in memory:
var testChart = nv.models.scatterChart();
On my (Chrome) console, the console will then print out the entire contents of the function you just created. It is interesting, but very long and difficult to interpret at a glance. And most of the code is encapsulated so you can't change it easily. You want to know which properties you can change. So run this code in the next line of your console:
for (keyname in testChart){console.log(keyname + " (" + typeof(testChart[keyname]) + ")");}
The console should now print out neatly the names of all the methods and objects that you can access from that chart function. Some of these will have their own methods and objects you can access; discover what they are by running the same routine, but replacing the testChart with testChart.propertyName, like this:
for (keyname in testChart.xAxis){console.log(keyname + " (" + typeof(testChart.xAxis[keyname]) + ")");}
Back to your problem. The little routine I suggested above doesn't sort the property names in any order, but skimming through the list you should see three options that relate to size (which was the data variable that the examples were using to set radius)
size (function)
sizeDomain (function)
sizeRange (function)
Domain and range are terms used by D3 scales, so that gives me a hint about what they do. Since you don't want to scale the dots, let's start by looking at just the size property. If you type the following in the console:
testChart.size
It should print back the code for that function. It's not terribly informative for what we're interested in, but it does show me that NVD3 follows D3's getter/setter format: if you call .property(value) you set the property to that value, but if you call .property() without any parameters, it will return back the current value of that property.
So to find out what the size property is by default, call the size() method with no parameters:
testChart.size()
It should print out function (d) { return d.size || 1}, which tells us that the default value is a function that looks for a size property in the data, and if it doesn't exist returns the constant 1. More generally, it tells us that the value set by the size method determines how the chart gets the size value from the data. The default should give a constant size if your data has no d.size property, but for good measure you should call chart.size(1); in your initialization code to tell the chart function not to bother trying to determine size from the data and just use a constant value.
Going back to the live code scatterplot can test that out. Edit the code to add in the size call, like this:
var chart = nv.models.scatterChart()
.showDistX(true)
.showDistY(true)
.color(d3.scale.category10().range())
.size(1);
chart.xAxis.tickFormat(d3.format('.02f'));
chart.yAxis.tickFormat(d3.format('.02f'));
Adding that extra call successfully sets all the dots to the same size -- but that size is definitely not 1 pixel, so clearly there is some scaling going on.
First guess for getting bigger dots would be to change chart.size(1) to chart.size(100). Nothing changes, however. The default scale is clearly calculating it's domain based on the data and then outputting to a standard range of sizes. This is why you couldn't get big circles by setting the size value of every data element to 0.99, even if that would create a big circle when some of the data was 0.01 and some was 0.99. Clearly, if you want to change the output size, you're going to have to set the .sizeRange() property on the chart, too.
Calling testChart.sizeRange() in the console to find out the default isn't very informative: the default value is null (nonexistent). So I just made a guess that, same as the D3 linear scale .range() function, the expected input is a two-element array consisting of the max and min values. Since we want a constant, the max and min will be the same. So in the live code I change:
.size(1);
to
.size(1).sizeRange([50,50]);
Now something's happening! But the dots are still pretty small: definitely not 50 pixels in radius, it looks closer to 50 square pixels in area. Having size computed based on the area makes sense when sizing from the data, but that means that to set a constant size you'll need to figure out the approximate area you want: values up to 200 look alright on the example, but the value you choose will depend on the size of your graph and how close your data points are to each other.
--ABR
P.S. I added the NVD3.js tag to your question; be sure to use it as your main tag in the future when asking questions about the NVD3 chart functions.
The radius is measured in pixels. If you set it to a value less than one, yes, you will have a very small circle. Most of the examples that use random numbers also use a scaling factor.
If you want all the circles to have a constant radius you don't need to set the value in the data, just set it when you add the radius attribute.
Not sure which tutorials you were looking at, but start here: https://github.com/mbostock/d3/wiki/Tutorials
The example "Three little circles" does a good step-by-step of the different things you can do with circles:
http://mbostock.github.io/d3/tutorial/circle.html

arbor js - save and load graph

I'm using arbor js to create diagrams using its force-based alorithm.
I would like to be able to save the x,y system coordinates of the nodes after the total energy has got below a certain point, so that I can load them back in when accessing the graph, to avoid having to re-process all the energy from scratch.
I have had two problems doing this:
sys.energy().sum always returns NaN
as an alternative I decided to use setTimeout to save the graph node positions after a given period of time has elapsed
While I have been able to save the nodes x,y system coordinates to DB, when I try to load the data into the graph (using sys.merge or sys.addNode) with saved x y coordinates, the graph fails to display, and an 'out of memory' message appears in the console log.
Here is an example of data with node x,y system coordinates that were saved, and which causes arbor js to crash which loading:
{"nodes":{"0":{"edgeCount":0,"x":13.11901,"y":14.89151,"id":0,"name":"Global"},"23":
{"edgeCount":1,"x":18.08981,"y":-0.8355745,"id":23,"name":"Aristotle"},"26":
{"edgeCount":1,"x":5.688836,"y":14.86863,"id":26,"name":"Socrates"},"27":
{"edgeCount":1,"x":14.84461,"y":-1.687457,"id":27,"name":"Christianity"},"34":
{"edgeCount":1,"x":-2.265221,"y":13.59168,"id":34,"name":"Maths"},"91":
{"edgeCount":11,"x":5.868572,"y":-1.315289,"id":91,"name":"Plato"},"92":
{"edgeCount":4,"x":-3.14131,"y":8.81194,"id":92,"name":"Virtue"},"127":
{"edgeCount":1,"x":-3.308347,"y":8.463552,"id":127,"name":"Poetry"},"131":
{"edgeCount":1,"x":7.605158,"y":-3.951363,"id":131,"name":"Wisdom"},"147":
{"edgeCount":1,"x":6.195698,"y":-4.572639,"id":147,"name":"Person"},"149":
{"edgeCount":1,"x":2.10395,"y":-2.390886,"id":149,"name":"Republic"},"171":
{"edgeCount":1,"x":3.359434,"y":-3.996424,"id":171,"name":"Justice"},"172":
{"edgeCount":1,"x":-0.2544371,"y":-4.218832,"id":172,"name":"Temperance"},"173":
{"edgeCount":1,"x":-8.773163,"y":2.587845,"id":173,"name":"Courage"},"178":
{"edgeCount":1,"x":-2.380451,"y":-5.787674,"id":178,"name":"Schopenhauer"},"194":
{"edgeCount":2,"x":-7.747643,"y":-1.653015,"id":194,"name":"Beauty"},"195":
{"edgeCount":1,"x":-10.45985,"y":-2.670299,"id":195,"name":"Objective"},"196":
{"edgeCount":1,"x":-10.64573,"y":-6.874766,"id":196,"name":"Truth"},"219":
{"edgeCount":1,"x":-6.22574,"y":-7.565969,"id":219,"name":"Theory of forms"},"221":
{"edgeCount":1,"x":-8.314561,"y":-7.570002,"id":221,"name":"Platinus"},"245":
{"edgeCount":0,"x":-13.20351,"y":-8.421284,"id":245,"name":"Diagram"},"254":
{"edgeCount":1,"x":-13.54734,"y":-7.7437,"id":254,"name":"Green"}},
"edges":{"23":{"91":{"context":{"id":0,"name":"Global"},"source":
{"id":23,"name":"Aristotle"},"predicate":{"id":21,"name":"studied with"},"target":
{"id":91,"name":"Plato"}}},"26":{"91":{"context":{"id":0,"name":"Global"},"source":
{"id":26,"name":"Socrates"},"predicate":{"id":2,"name":"inspires"},"target":
{"id":91,"name":"Plato"}}},"91":{"149":{"context":{"id":0,"name":"Global"},"source":
{"id":91,"name":"Plato"},"predicate":{"id":1,"name":"writes"},"target":
{"id":149,"name":"Republic"}},"219":{"context":{"id":0,"name":"Global"},"source":
{"id":91,"name":"Plato"},"predicate":{"id":1,"name":"writes"},"target":{"id":219,"name":"Theory of forms"}},"27":{"context":{"id":0,"name":"Global"},"source":{"id":91,"name":"Plato"},"predicate":
{"id":3,"name":"influences"},"target":{"id":27,"name":"Christianity"}},"178":{"context":
{"id":0,"name":"Global"},"source":{"id":91,"name":"Plato"},"predicate":
{"id":3,"name":"influences"},"target":{"id":178,"name":"Schopenhauer"}},"221":{"context":
{"id":0,"name":"Global"},"source":{"id":91,"name":"Plato"},"predicate":
{"id":3,"name":"influences"},"target":{"id":221,"name":"Platinus"}},"254":{"context":
{"id":245,"name":"Diagram"},"source":{"id":91,"name":"Plato"},"predicate":
{"id":28,"name":"is"},"target":{"id":254,"name":"Green"}},"34":{"context":
{"id":0,"name":"Global"},"source":{"id":91,"name":"Plato"},"predicate":{"id":33,"name":"is associated with"},"target":{"id":34,"name":"Maths"}},"127":{"context":
{"id":0,"name":"Global"},"source":{"id":91,"name":"Plato"},"predicate":{"id":47,"name":"is obsessed with"},"target":{"id":127,"name":"Poetry"}},"147":{"context":
{"id":0,"name":"Global"},"source":{"id":91,"name":"Plato"},"predicate":{"id":56,"name":"is type of"},"target":{"id":147,"name":"Person"}}},"92":{"131":{"context":{"id":91,"name":"Plato"},"source":
{"id":92,"name":"Virtue"},"predicate":{"id":28,"name":"is"},"target":
{"id":131,"name":"Wisdom"}},"171":{"context":{"id":91,"name":"Plato"},"source":
{"id":92,"name":"Virtue"},"predicate":{"id":28,"name":"is"},"target":
{"id":171,"name":"Justice"}},"172":{"context":{"id":91,"name":"Plato"},"source":
{"id":92,"name":"Virtue"},"predicate":{"id":28,"name":"is"},"target":
{"id":172,"name":"Temperance"}},"173":{"context":{"id":91,"name":"Plato"},"source":
{"id":92,"name":"Virtue"},"predicate":{"id":28,"name":"is"},"target":
{"id":173,"name":"Courage"}}},"194":{"195":{"context":{"id":91,"name":"Plato"},"source":
{"id":194,"name":"Beauty"},"predicate":{"id":28,"name":"is"},"target":
{"id":195,"name":"Objective"}},"196":{"context":{"id":91,"name":"Plato"},"source":
{"id":194,"name":"Beauty"},"predicate":{"id":33,"name":"is associated with"},"target":
{"id":196,"name":"Truth"}}}}}
I can find no examples of graphs where the node x,y coordinates are in the input data.
Looking at https://github.com/samizdatco/arbor/blob/master/src/physics/system.js#L83 it seems that it should be alright to include x and y value in the data dictionary. I'm not really sure from your example how you pass the data to the methods. Maybe try just adding a few of the nodes and see where they are placed. I have the same problem with the energy being NaN. Probably using a debugger will help.

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