Endpoint for EPU data per month

[peterdesmet]

For the overview chart (see #27), I need EPU data per month. Instead of querying for all data per day and then aggregating on the frontend, I assume it would be better to create an endpoint/option for average EPU data per month? E.g.:

https://epu-index.herokuapp.com/api/epu/?format=json&aggregate=month

I don't require the start/end options for this query.

[niconoe]

Hi guys, it's now implemented at https://epu-index.herokuapp.com/epu-per-month/ !

[peterdesmet]

@niconoe @bartaelterman the API currently gives me unordered (as an object), rather than array:

{
2003-08: 0.684210526263158,
2003-09: 1.0144927535652173,
2003-01: 0.8787878786818183,
2003-02: 0.8070175437894737,
2003-03: 0.8095238095714288,
2003-04: 0.99999999995,
2003-05: 1.1363636363636365,
2003-06: 1.3,
...
}

I might be able to work around this (as the charting library C3 will probably place time data in order), but it would be more convenient if I get the data as an array, just like the day API does. Bart, maybe you can help me figure out how the mapping function should work with the current data I get? How do I get the current data into two arrays?

[bartaelterman]

One solution would be (not tested):

First create an array of the dates:

var dates = [];
for (var key in response_data) {
    if (response_data.hasOwnProperty(key)) {
        dates.push(key)
    }
}

Now sort it (either as strings, or convert it to Dates first)

dates.sort(); // I think this sorts the array, and does not return a new sorted array so no need to assign the result to a new variable

And create a new array with the epu-index data in the same order

var epu_data = dates.map(function (x) {return response_data[x];}); // map will respect the order of the dates array

This should give you 2 arrays, sorted by date.

Having said all that, I would plead for letting the API return an array to keep our API more consistent.

[peterdesmet]

@niconoe, thanks for the API. After some discussion with @bartaelterman, we think it's better to structure this API similar to the epu API. Here are the new requirements:

1. Return the data as an array:

[
    {
        "month": "2010-08",
        "epu": 3.141592
    },
    {
        "month": "2010-09",
        "epu": 12.49
    },
]

1. I would include api in the endpoint URL: https://epu-index.herokuapp.com/api/epu-per-month/ (cf. https://epu-index.herokuapp.com/api/epu/)

Question: I noticed that the epu API does not sort chronologically. @bartaelterman, do you think that is required? The chart can handle unsorted data for now.

[bartaelterman]

Technically, sorting the API data chronologically will make no difference. The charting libraries will always sort the data before plotting them. Nevertheless, I would also vote for a sorted API.

[peterdesmet]

Sorted is also consistent with the requirements in #45.

[niconoe]

That's implemented, please test!

[peterdesmet]

Works great!