Develop Reference

How to match up category labels with multiple series?

I'm working on a project to brush up on my JS, and I'm finding Highcharts rather challenging. What I've done is set up project that pulls in current JSON data from an API, and displays results on a map. When you click on a state, you can view the historical data for that state. if you shift click, you can view more than one state.
My x-axis is formatted with dates from each state, as not each state began tracking data at the same time. When multiple states are selected, the information is incorrect because even though they all have the same date for the most recent data point (today), the first data point in the date array varies. For instance, if you click New York, their first data point starts on 3/04, but if you click Connecticut, the first data point starts on 3/07.
Is there a way I can reconcile this? Can I have my categories start from the most recent data point and work backwards, so the data points for today are concurrent?
Here's my pen: https://codepen.io/maxpalmer/pen/rNVRzVX?editors=0010
Stackoverflow is requiring I post some code, so here is the function I wrote that reassembles the api data into an array for each state for the area chart:
for (i = 0; i < stateAbbrevs.length; i++){
var values = new Array(), categories = new Array();
// var categories = new Array();
var state = stateAbbrevs[i];
var stateObj = jsonData.filter(obj => obj.state == state);
for (x = 0; x < stateObj.length; x++) {
var value = stateObj[x].positive;
var date = formatDate(stateObj[x].date);
var name = stateNames[i];
values.push(value);
categories.push(date);
}
values.reverse();
categories.reverse();
historicData[state] = {
name: name,
data: values,
categories: categories
};
}
}```

Ah, found it in the myriad Highcharts documentation. Comes down to reversing my data array, and then reversing it in the highcharts x-axis options.
https://api.highcharts.com/highcharts/xAxis.reversed

Angular nvD3 Stacked Area Chart Data Series Format

I am trying to use my own data in a nvD3 stacked area chart. The sample data format from the Angular nvD3 site has a format like this:
[{
"key":"Series 1",
"values":[[1025409600000,0],[1028088000000,-6.3382185140371]]
},
{
"key":"Series 2",
"values":[[1025409600000,0],[1028088000000,0]]
}]
I have data coming from my database in this format:
[{
"Loc_Cnt":6,"Num_Cars":552,"Num_Employees":34,"active_month":"2017-10-01T00:00:00"
},
{
"Loc_Cnt":4,"Num_Cars":252,"Num_Employees":14,"active_month":"2017-11-01T00:00:00"
}]
I am trying to graph from my data, three series (Series 1: Flt_Cnt, Series 2: Num_Cars, Series 3: Num_Employees). For each series, the X axis value being the active_month date, and the Y axis value being the series value.
How can I either A) convert my data to look like the sample data easily, or B) use my data as is in the AngularJs nvd3 chart? I feel a .forEach on the array would not be efficient for larger data sets, and not as easy to read. I tried to use d3.nest in some way, but haven't been able to get a correct format. Thanks for your help!

It's not elegant, but I brute forced a way to my solution. If there are any better solutions, please do let me know.
var Loc_Cnt = [];
var Num_Cars = [];
var Num_Employees = [];
var obj = {};
//arr is the array of values in my format
arr.forEach(function (element) {
//need the date in milisecond format
var date = new Date(element.active_month);
var time = date.getTime();
//load corresponding arrays
Loc_Cnt.push([time, element.Loc_Cnt]);
Num_Cars.push([time, element.Num_Cars]);
Num_Employees.push([time, element.Num_Employees]);
});
//load each key/values pair into new object
obj["Loc_Cnt"] = Loc_Cnt;
obj["Num_Cars"] = Num_Cars;
obj["Num_Employees"] = Num_Employees;
//d3.entries creates an object of key/VALUEs
arrRollup = d3.entries(obj);
//change the key word values to value
var i;
for (i = 0; i < arrRollup.length; i++) {
arrRollup[i].values = arrRollup[i]['value'];
delete arrRollup[i].value;
}

Choropleth Alternative Method and more

In my previous post1 and post2, i managed to fix the choropleth map/legend issue + draw circles problems when drawing a map.
When i follow this must-do tutorial about choropleth and when i search on internet i always find the same logic
d3.csv("my.csv", function(data) {
d3.json(myjson, function(json) {
for (var i = 0; i < data.length ; i++) {
//Grab state name
var dataState = data[i].nom;
//Grab data value, and convert from string to float
var dataValue = data[i].population;
//Find the corresponding state inside the GeoJSON
for (var j = 0; j < json.features.length; j++) {
var jsonState = json.features[j].properties.nom;
if (dataState == jsonState) {
//Copy the data value into the JSON
json.features[j].properties.CA = dataValue;
//Stop looking through the JSON
break;
}
}
}
So in my case, i have a map with 75 path (1 path=region) and my csv file have 75 rows (1 row = 1 path)
Now i'm trying to do things a little differently
My new csv has N rows (N > 75, let's say 200) and for each row, a store (properties+lat+lon) is affected to a path ==> i can have 5 stores/path e.g
Here are my questions :
1) How do i write my choropleth code differently ==> I'd like to scan the csv file and return for each distinct path the sum of specific properties (here "income") in order to write it on my json file ???
2) When i click on a specific region/path, i'd like to display on a new div (in my case #output) the json file corresponding to my region (basicaly i have 75 json files "region1.json", "region2.json" and so on...") with circles inside (one circle = one store, in my csv file "name" column") ==> How do i retrieve this "on click value" and call the correct/corresponding json file ????
3) Finally, if i click on a displayed specific circle of the #output div, i'd like to have on a third div a chart ==> How do i writte correctly my 3rd div so it is correctly displayed (css, other ?? ==> it can be applied to #output too) ??
Thank you so much for reading this request and for your availability and help
Here's the plunker file (do not mind the sales.csv file, i just used it to try displaying something when i click on the path
Thanks again

d3 nest roll up is the solution
d3.csv("source-data.csv", function(error, csv_data) {
var data = d3.nest()
.key(function(d) { return d.date;})
.rollup(function(d) {
return d3.sum(d, function(g) {return g.value; });
}).entries(csv_data);
});
More info here

Row Chart grouping on two text dimensions [duplicate]

I need to create a rowchart in dc.js with inputs from multiple columns in a csv. So i need to map a column to each row and each columns total number to the row value.
There may be an obvious solution to this but i cant seem to find any examples.
many thanks
S
update:
Here's a quick sketch. Apologies for the standard
Row chart;
column1 ----------------- 64 (total of column 1)
column2 ------- 35 (total of column 2)
column3 ------------ 45 (total of column 3)

Interesting problem! It sounds somewhat similar to a pivot, requested for crossfilter here. A solution comes to mind using "fake groups" and "fake dimensions", however there are a couple of caveats:
it will reflect filters on other dimensions
but, you will not be able to click on the rows in the chart in order to filter anything else (because what records would it select?)
The fake group constructor looks like this:
function regroup(dim, cols) {
var _groupAll = dim.groupAll().reduce(
function(p, v) { // add
cols.forEach(function(c) {
p[c] += v[c];
});
return p;
},
function(p, v) { // remove
cols.forEach(function(c) {
p[c] -= v[c];
});
return p;
},
function() { // init
var p = {};
cols.forEach(function(c) {
p[c] = 0;
});
return p;
});
return {
all: function() {
// or _.pairs, anything to turn the object into an array
return d3.map(_groupAll.value()).entries();
}
};
}
What it is doing is reducing all the requested rows to an object, and then turning the object into the array format dc.js expects group.all to return.
You can pass any arbitrary dimension to this constructor - it doesn't matter what it's indexed on because you can't filter on these rows... but you probably want it to have its own dimension so it's affected by all other dimension filters. Also give this constructor an array of columns you want turned into groups, and use the result as your "group".
E.g.
var dim = ndx.dimension(function(r) { return r.a; });
var sidewaysGroup = regroup(dim, ['a', 'b', 'c', 'd']);
Full example here: https://jsfiddle.net/gordonwoodhull/j4nLt5xf/5/
(Notice how clicking on the rows in the chart results in badness, because, what is it supposed to filter?)

Are you looking for stacked row charts? For example, this chart has each row represent a category and each color represents a sub-category:
Unfortunately, this feature is not yet supported at DC.js. The feature request is at https://github.com/dc-js/dc.js/issues/397. If you are willing to wade into some non-library code, you could check out the examples referenced in that issue log.
Alternatively, you could use a stackable bar chart. This link seems to have a good description of how this works: http://www.solinea.com/blog/coloring-dcjs-stacked-bar-charts

Efficiently detect missing dates in array and inject a null (highcharts and jquery)

I'm using highcharts.js to visualize data series from a database. There's lots of data series and they can potantially change from the database they are collected from with ajax. I can't guarantee that they are flawless and sometimes they will have blank gaps in the dates, which is a problem. Highcharts simply draws a line through the entire gap to the next available date, and that's bad in my case.
The series exists in different resolutions. Hours, Days and Weeks. Meaning that a couple of hours, days or weeks can be missing. A chart will only show 1 resolution at a time on draw, and redraw if the resolution is changed.
The 'acutal' question is how to get highcharts to not draw those gaps in an efficient way that works for hous, days and weeks
I know highcharts (line type) can have that behaviour where it doesn't draw a single line over a gap if the gap begins with a null.
What I tried to do is use the resolution (noted as 0, 1, 2 for hour day or week), to loop through the array that contains the values for and detect is "this date + 1 != (what this date + 1 should be)
The code where I need to work this out is here. Filled with psudo
for (var k in data.values) {
//help start, psudo code.
if(object-after-k != k + resolution){ //The date after "this date" is not as expected
data.values.push(null after k)
}
//help end
HC_datamap.push({ //this is what I use to fill the highchart later, so not important
x: Date.parse(k),
y: data.values[k]
});
}
the k objects in data.values look like this
2015-05-19T00:00:00
2015-05-20T00:00:00
2015-05-21T00:00:00
...and more dates
as strings. They can number in thousands, and I don't want the user to have to wait forever. So performance is an issue and I'm not an expert here either
Please ask away for clarifications.

I wrote this loop.
In my case my data is always keyed to a date (12am) and it moves either in intervals of 1 day, 1 week or 1 month. Its designed to work on an already prepared array of points ({x,y}). Thats what dataPoints is, these are mapped to finalDataPoints which also gets the nulls. finalDataPoints is what is ultimately used as the series data. This is using momentjs, forwardUnit is the interval (d, w, or M).
It assumes that the data points are already ordered from earliest x to foremost x.
dataPoints.forEach(function (point, index) {
var plotDate = moment(point.x);
finalDataPoints.push(point);
var nextPoint = dataPoints[index+1];
if (!nextPoint) {
return;
}
var nextDate = moment(nextPoint.x);
while (plotDate.add(1, forwardUnit).isBefore(nextDate)) {
finalDataPoints.push({x: plotDate.toDate(), y: null});
}
});

Personally, object with property names as dates may be a bit problematic, I think. Instead I would create an array of data. Then simple loop to fill gaps shouldn't be very slow. Example: http://jsfiddle.net/4mxtvotv/ (note: I'm changing format to array, as suggested).
var origData = {
"2015-05-19T00:00:00": 20,
"2015-05-20T00:00:00": 30,
"2015-05-21T00:00:00": 50,
"2015-06-21T00:00:00": 50,
"2015-06-22T00:00:00": 50
};
// let's change to array format
var data = (function () {
var d = [];
for (var k in origData) {
d.push([k, origData[k]]);
}
return d;
})();
var interval = 'Date'; //or Hour or Month or Year etc.
function fillData(data, interval) {
var d = [],
now = new Date(data[0][0]), // first x-point
len = data.length,
last = new Date(data[len - 1][0]), // last x-point
iterator = 0,
y;
while (now <= last) { // loop over all items
y = null;
if (now.getTime() == new Date(data[iterator][0]).getTime()) { //compare times
y = data[iterator][1]; // get y-value
iterator++; // jump to next date in the data
}
d.push([now.getTime(), y]); // set point
now["set" + interval](now.getDate() + 1); // jump to the next period
}
return d;
}
var chart = new Highcharts.StockChart({
chart: {
renderTo: 'container'
},
series: [{
data: fillData(data, interval)
}]
});
Second note: I'm using Date.setDay() or Date.setMonth(), of course if your data is UTC-based, then should be: now["setUTC" + interval].