DC.js Choropleth filtering Issue - dc.js

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!

Related

How to show only limited number of records in box plot dc.js

I want to show the most recent 10 bins for box plot.
If a filter is applied to the bar chart or line chart, the box plot should show the most recent 10 records according to those filters.
I made dimension by date(ordinal). But I am unable to get the result.
I didn’t get how to do it with a fake group. I am new to dc.js.
The pic of scenario is attached. Let me know if anyone need more detail to help me.
in image i tried some solution by time scale.
You can do this with two fake groups, one to remove the empty box plots, and one to take the last N elements of the resulting data.
Removing empty box plots:
function remove_empty_array_bins(group) {
return {
all: function() {
return group.all().filter(d => d.value.length);
}
};
}
This just filters the bins, removing any where the .value array is of length 0.
Taking the last N elements:
function cap_group(group, N) {
return {
all: function() {
var all = group.all();
return all.slice(all.length - N);
}
};
}
This is essentially what the cap mixin does, except without creating a bin for "others" (which is somewhat tricky).
We fetch the data from the original group, see how long it is, and then slice that array from all.length - N to the end.
Chain these fake together when passing them to the chart:
chart
.group(cap_group(remove_empty_array_bins(closeGroup), 5))
I'm using 5 instead of 10 because I have a smaller data set to work with.
Demo fiddle.
This example uses a "real" time scale rather than ordinal dates. There are a few ways to do ordinal dates, but if your group is still sorted from low to high dates, this should still work.
If not, you'll have to edit your question to include an example of the code you are using to generate the ordinal date group.

Filter list for many pie charts and removing them

I've got 2 pie charts with data like:
data: [
{diseaseType: 'Cancer', diseaseDetails: 'Lung cancer', quantity: 100},
{diseaseType: 'Diebetes', diseaseDetails: 'Unspecific', quantity: 650},
{diseaseType: 'Cancer', diseaseDetails: 'Breast cancer', quantity: 80}
]
i'm tying to get list of filters and able to remove them by user like (it's only controlled test code):
this.diseasePieChart.filters().splice(0, 1)
dc.renderAll()
it's updating first chart, but second (connected with first) not, it's stay like it was before remove filter.
Second chart i'm rendering like this:
self.diseasePieChart.on('filtered.monitor', function (chart) {
// create dimensions etc and render second chart
}
I also tried to do again crossfilter(data) after filter remove. When i'm calling dc.filterAll all filters are reset.
thanks for any help !
The correct entry points for changing filters are chart.filter() or chart.replaceFilter(), depending on whether you are trying to toggle individual items or change the entire array of filters at once.
As you found out, manipulating the array of filters inside the chart might affect the way the chart draws, but it won't convey the change to the crossfilter dimension and the other charts.
Note that as documented in the link above, the accepted type for the parameter for each of these functions is a little surprising:
The filter parameter can take one of these forms:
A single value: the value will be toggled (added if it is not present in the current filters, removed if it is present)
An array containing a single array of values ([[value,value,value]]): each value is toggled
When appropriate for the chart, a dc filter object such as
dc.filters.RangedFilter for the dc.coordinateGridMixin charts
dc.filters.TwoDimensionalFilter for the heat map
dc.filters.RangedTwoDimensionalFilter for the scatter plot
null: the filter will be reset using the resetFilterHandler
So if you want to get the array, remove an item, and then set it back, you could either:
var filters = chart.filters().slice(0); // copy the array of filters
filters.splice(0,1)
chart.replaceFilter([filters])
.redrawGroup();
or (using the toggle feature):
chart.filter(chart.filters()[0])
.redrawGroup();
Note that you usually want to redraw, not render, after changing a filter. This will allow the animated transitions to display, and is a little bit quicker.
Also, chart.redrawGroup is the same as dc.redrawAll() but it's a little safer in case you have more chart groups in the future.

snapping brush to the next x value? [dc.js]

I have a line chart and data in the form
[{
time: "2016-4-29"
total: 23242
},
{
time: "2016-5-16
total: 3322
}
...
]
I'm trying to filter on the x-axis with the brush, however, since I don't have every single date, if I brush in a small range, the filter handler seems to return an empty array for my filters
I've set up my line chart's x-axis like so:
.x(d3.time.scale().domain([minDate,maxDate]))
is there a way to make it so a user can only filter on dates that are in the dataset?
I would like the brush to snap to dates in the dataset.
it seems like whats happening is that you are able to brush between ticks..so it doesn't know what it selected.
I'm going to answer the easier question: How do I create a brush that will not allow nothing to be selected?
In other words, if the brush contains no data, do not allow it to take.
There are two parts to the solution. First, since any chart with a brush will remove the old filter and then add the new filter, we can set up the addFilterHandler to reject any filter that does not contain non-zero bins:
spendHistChart.addFilterHandler(function(filters, filter) {
var binsIn = spendHistChart.group().all().filter(function(kv) {
return filter.isFiltered(kv.key) && kv.value;
});
console.log('non-empty bins in range', binsIn.length);
return binsIn.length ? [filter] : [];
});
That's the straightforward part, and incidentally I think you could probably modify it to snap the brush to existing data. (I haven't tried it, though.)
The more tricky part is that this won't get rid of the brush, it just doesn't apply the filter. So the chart will end up in an inconsistent state.
We need to detect when the brush action has finished, and if there is no filter at that point, explicitly tell the chart to clear the filter:
spendHistChart.brush().on('brushend.no-empty', function() {
if(!spendHistChart.filters().length)
window.setTimeout(function() {
spendHistChart.filterAll().redraw();
}, 100);
});
We need a brief delay here, because if we respond to brushend synchronously, the chart may still be responding to it, causing bickering and dissatisfaction.
As a bonus, you get kind of a "nah-ah" animation because of the unintentional remove-brush animation.
demo fiddle

AmCharts. Aligning balloons

I've spent a lot of time finding the solution, but i can't see any property in AmChatrts documentation that can align balloons not vertically. Actually, I just want to see all balloons, but not in one column. Can anybody help me?
There is currently no way to make the balloons stack in any different way than in once column. However, there are a few alternatives you can consider.
1) Displaying just one balloon.
To do that, set oneBalloonOnly to true:
var chart = AmCharts.makeChart("chartdiv",{
...
"chartCursor": {
"oneBalloonOnly": true
}
});
This will make the cursor display just one balloon of the closest graph.
2) Disable balloons and use a legend instead.
To disable balloons, simply set [valueBalloonsEnabled][3] in chart cursor's settings to false.
var chart = AmCharts.makeChart("chartdiv",{
...
"chartCursor": {
"valueBalloonsEnabled": false
},
"legend": {}
});
The legend will show relative value next to each graph title when you hover over the chart.
3) Consolidate values from multiple graphs into a single balloon.
To do that, use graph's balloonText property. It lets you reference to any field in data, so you can make it display values from any graph.
Here's a good example of the above.
Here's a good demo on how to do that.

Line Plus Bar with Multi Bars?

I'm trying to make an chart using the default line plus bar chart, but I want to use two or more streams in the bars, is it possible?
Currently, when I try to do this, I got some trouble with the effects of the chart, and so I can't show properly the hover balloon of the bars, he always display the data of just one of the streams. But the main problem is the dates of x axis, displaying 1970's dates, when I remove the second stream of bars, the dates display well:
Anyone already tried to do this kind of chart successfully?
EDIT
Adding Fiddles:
Fiddle with two columns stream and messy dates
Fiddle with just one column stream and ok dates
I'm calling this kind of graph:
linePlusBarChart()
The problem with the dates is that your data contains timestamps (i.e. in seconds), but Javascript expects milliseconds. This is easily fixed by multiplying the values by 1000:
series.values = series.values.map(function (d) {
return {
x: d[0]*1000,
y: d[1]
}
});
The tooltip problem is actually a bug in NVD3 -- it's not meant to be used this way. The problem boils down to the mouseover handler assuming that the first item of the data is representative of what you want. You can fix this for your case by selecting the item by data point number modulo 2 (because there're two bars):
.on('mouseover', function(d,i) {
d3.select(this).classed('hover', true);
dispatch.elementMouseover({
point: d,
series: data[i%2],
pos: [x(getX(d,i)), y(getY(d,i))],
pointIndex: i,
seriesIndex: i%2,
e: d3.event
});
})
This will only work for exactly two bar series though. Updated jsfiddle with the modified NVD3 code here.

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