We Keep Coding

Extracting monthly values from data with irregular dates

I have bunch of electricity meter readings which have irregular dates. See below :
ReadingDate Meter
19/01/2021 5270
06/03/2021 5915
11/05/2021 6792
08/07/2021 7367
9/9/2021 8095
8/11/2021 8849
02/12/2021 9065
17/01/2022 9950
Now I'd like to transform this into monthly readings, using just this data, to end up with a table like this
Month Usage
2021-01 452
2021-02 393
2021-03 416
2021-04 399
2021-05 341
2021-06 297
2021-07 347
2021-08 358
2021-09 369
2021-10 389
2021-11 295
2021-12 586
2022-01 308
Now, I have a working solution, but I'm sure there's a more beautiful concise way of doing it.
What I do is to create an intermediate array that has one line for each date between first and last meter readings.
Each item in the array has 3 values :
the date
the average value for that date (calculated by counting the days between meter readings and dividing that by change in the meter.
the corresponding month
The last step then is to loop over this intermediate array and sum the values for each different month.
Here's the working code (its taken from Google Apps Script so please ignore the spreadsheet specific stuff:
var DailyAveragesArray = [['Date','Usage','Month']];
var monthlyObject = {};
var monthlyArray = [['Month','Usage']];
function calculateAverageDailyFigures() {
// give indices for the useful columns, 0 numbered
var ReadingDateColumn = 0;
var MeterReading = 1;
// Read into an array
var MeterReadingData = ss.getDataRange().getValues() // Get array of values
const sortedReadings = MeterReadingData.slice(1).sort((a, b) => a[0] - b[0]);
// from https://flaviocopes.com/how-to-sort-array-by-date-javascript/
// First calculate the number of days and average daily figure for each row
// Note we don't do this for the last row
for(i=0; i < sortedReadings.length - 1 ; i++){
var NumberOfDays = (sortedReadings[i+1][0] - sortedReadings[i][0])/(1000*3600*24);
sortedReadings[i].push(NumberOfDays);
var MeterDifference = sortedReadings[i+1][1] - sortedReadings[i][1];
var AverageDailyFigure = MeterDifference/NumberOfDays;
sortedReadings[i].push(AverageDailyFigure);
}
BuildDailyArray(sortedReadings);
}
function BuildDailyArray(sortedReadings){
// For each row in sorted , loop from the date to the next date-1 and create columns date and Usage
for(i=0; i<sortedReadings.length -1 ;i++){
for (var d = sortedReadings[i][0]; d < sortedReadings[i+1][0]; d.setDate(d.getDate() + 1)) {
var newDate = new Date(d);
var month = newDate.getFullYear() + '-' + ('0' + (newDate.getMonth() + 1)).slice(-2);
DailyAveragesArray.push([newDate,sortedReadings[i][3],month]);
// Check if the month is in the object and add value, otherwise create object an add value
if(month in monthlyObject){
monthlyObject[month] = monthlyObject[month] + sortedReadings[i][3];
} else {
Logger.log('Didnt find month so create it');
monthlyObject[month] = sortedReadings[i][3];
}
}
}
Logger.log(DailyAveragesArray.length);
Logger.log(monthlyObject);
var DailyUsageData = ss.getRange('D1:F'+DailyAveragesArray.length);
DailyUsageData.setValues(DailyAveragesArray);
BuildMonthlyArray();
}
function BuildMonthlyArray(){
const keys = Object.keys(monthlyObject);
Logger.log(keys);
keys.forEach((key, index) => {
monthlyArray.push([key,Math.round(monthlyObject[key])]);
});
var MonthlyUsageData = ss.getRange('H1:I'+monthlyArray.length);
MonthlyUsageData.setValues(monthlyArray);
}
So, my question is, how would I do this nicer, more beautifully, not so verbose ?
I'm not sure what the correct term is for what I want to do. I don't think it's resampling .
I'd appreciate any comments.
Thanks / Colm

Here is my shot on this.
The way i'm doing it:
Initializing all days and its value
Grouping by month
Calculating the average per month
Explanation a bit more precise
initDateFromString
The method initDateFromString takes a dates with the format DD/MM/YYYY and return the associated js date object
initAllDates
The method initAllDates will split the data into day and add the average value of the difference for each day
for example, for the first two readings, it will result to an array of dates looking like :
date
value
19/01/2021
14.02
20/01/2021
14.02
....
....
05/03/2021
14.02
06/03/2021
14.02
The value 14.02 comme from the following calcul :
(newReadingMeter - oldReadingMeter)/nbDaysBetweenDates
Which in this example is (5915 - 5270)/46 = 14.02
joinToMonth
The joinToMonth method will then group the days into month with all the days value summed !
const data = [{
ReadingDate: '19/01/2021',
Meter: 5270
},
{
ReadingDate: '06/03/2021',
Meter: 5915
},
{
ReadingDate: '11/05/2021',
Meter: 6792
},
{
ReadingDate: '08/07/2021',
Meter: 7367
},
{
ReadingDate: '9/9/2021',
Meter: 8095
},
{
ReadingDate: '8/11/2021',
Meter: 8849
},
{
ReadingDate: '02/12/2021',
Meter: 9065
},
{
ReadingDate: '17/01/2022',
Meter: 9950
}
]
function initDateFromString(dateString){
let dateParts = dateString.split("/");
return new Date(+dateParts[2], dateParts[1] - 1, +dateParts[0]);
}
function initAllDates(data){
let dates = []
let currentValue = data.shift()
const currentDate = initDateFromString(currentValue.ReadingDate)
data.forEach(metric => {
const date = initDateFromString(metric.ReadingDate)
const newDates = []
while(currentDate < date){
newDates.push({date: new Date(currentDate)})
currentDate.setDate(currentDate.getDate() + 1)
}
dates = dates.concat(newDates.map(x => {
return {Usage: (metric.Meter - currentValue.Meter) / newDates.length, date: x.date}}
))
currentDate.setDate(date.getDate())
currentValue = metric
})
return dates
}
function joinToMonth(dates){
return dates.reduce((months, day) => {
const month = day.date.getMonth()
const year = day.date.getFullYear()
const existingObject = months.find(x => x.month === month && x.year === year)
if (existingObject) {
existingObject.total += day.Usage
} else {
months.push({
month: day.date.getMonth(),
year: day.date.getFullYear(),
total: day.Usage,
})
}
return months;
}, []);
}
const dates = initAllDates(data)
const joinedData = joinToMonth(dates)
console.log(joinedData)

Filter returns everything But should only return some

I am writing a function to limit search results from an array of objects. It seems to be working mostly... but still returns the unwanted objects.
Here is my code/explanation so far - Can you help me figure out why it still returns the unwanted objects?
I start by filtering my array, tourBands, to include only bands that have certain event types. This works fine.
The second .filter() is where I am having issues. This is filtering the bands that are in town within 3 days before the selected performanceDate. The problem is even though the console.log() works at the end of the second .filter(), it still returns the band even when it shouldnt.
The code below has comments to explain whats going on.
{
bandTypes === "touring"
? tourBands
.filter(band => {
if(showType !== 'Show Type'){
return band.showTypes.includes(showType)
}else {
return band
}
})
.filter(band => {
//User Clicks Button to Search within 3 days of the tourDate. This sets filterTourBandsByDate to true.
if(filterTourBandsByDate){
//Each Band may have more than 1 tour date.. so I now start filtering through all the tour dates. This Works.
band.bandTour.filter(tourDate => {
//Now I check to see if this tour date is within 100 miles of the savedLocation, which is their search location. This works.
let distanceToSearch = turf.distance(tourDate.geometry.coordinates, savedLocation, {units: 'miles'})
if(distanceToSearch <= 100){
//If the specific tour location is within 100 miles of the saved location, I need to make sure that the tour location being filtered is actuall upcoming and not in the past.
let year = tourDate.geometry.tourDate.slice(0,4)
let month = tourDate.geometry.tourDate.slice(5, 7)
let day = tourDate.geometry.tourDate.slice(8)
let tourDateFormatted = new Date(year, month - 1, day)
//Check to make sure the tour date is upcoming - This works.
if(new Date() < tourDateFormatted ){
//Now I am going to change the tour date to 3 days before the actual tour date. Then i'll check to see if the performanceDate (The users entered date) is past the new date.
tourDateFormatted.setDate(tourDateFormatted.getDate() - 3);
if(performanceDate > tourDateFormatted ){
console.log(tourDate)
//Returns Correct Tour Date in the correct location. If I select a date that shouldnt return the band, the console.log does NOT fire, but it still returns the band.
return band
}
}
}
})
}else{
return band
}
})
.reduce(
(allPosts, band) =>
allPosts.concat(
(band.youtube.length > 0 &&
band.bandBio !== "n/a" &&
band.bandGenre !== "n/a")
? band.posts.map((post) => ({ post, band }))
: []
),
[]
)
.sort((a, b) => new Date(b.post.date) - new Date(a.post.date))
.slice(0, page * 10)
.map(({ post, band }) => convertPost(post, band))
: null
}

In your second .filter function, you're not always returning a value. You are doing a search operation with a band.bandTour.filter(...) call, but the value you return from that is not going to bubble out and be the result of the second filter function.
You should be able to replace that third nested filter with a loop. Alternately, you can replace that third .filter(...) call with a .some(...) (since you're trying to find if one value matches).
Loop version:
.filter(band => {
if(filterTourBandsByDate){
for (const tourDate of band.bandTour) {
let distanceToSearch = turf.distance(tourDate.geometry.coordinates, savedLocation, {units: 'miles'})
if(distanceToSearch <= 100){
let year = tourDate.geometry.tourDate.slice(0,4)
let month = tourDate.geometry.tourDate.slice(5, 7)
let day = tourDate.geometry.tourDate.slice(8)
let tourDateFormatted = new Date(year, month - 1, day)
if(new Date() < tourDateFormatted ){
tourDateFormatted.setDate(tourDateFormatted.getDate() - 3);
return (performanceDate > tourDateFormatted);
}
}
}
} else {
return true
}
})
Function chaining version:
.filter(band => !filterTourBandsByDate || band.bandTour.some(tourDate => {
let distanceToSearch = turf.distance(tourDate.geometry.coordinates, savedLocation, {units: 'miles'})
if(distanceToSearch <= 100){
let year = tourDate.geometry.tourDate.slice(0,4)
let month = tourDate.geometry.tourDate.slice(5, 7)
let day = tourDate.geometry.tourDate.slice(8)
let tourDateFormatted = new Date(year, month - 1, day)
if(new Date() < tourDateFormatted ){
tourDateFormatted.setDate(tourDateFormatted.getDate() - 3);
return performanceDate > tourDateFormatted;
}
}
})

Javascript Get Sequential Dates in Array cross week and month

I have an array with the following values (example):
[
1491408000000,
1491494400000,
1491753600000,
1493222400000,
1493308800000,
1493568000000
]
Where the index is a date time. The date time will always be at 12:00:00 on a date.
In this example, the first 3 dates are consecutive cross weekend (weekend is holiday so count as leave), then another group of 3 dates cross weekend and month.
Now, what I am trying to do is find sequential dates (cross week and month) and put them into an array as follows:
[
1491408000000,
1491494400000,
1491753600000
],
[
1493222400000,
1493308800000,
1493568000000
]
I have tried the following code to get the sequential dates but this cannot cross week and month, how to modify the code to get above result? Any help would be much appreciated!
var timeValue = new Date(dateReview).getTime();
valueCon.push(timeValue);
var k = 0;
sortedValue[k] = [];
valueCon.sort( function ( a, b ){
return +a > +b ? 1 : +a == +b ? 0: -1;
})
.forEach( function( v , i ){
var a = v,b = valueCon[i+1]||0;
sortedValue[k].push( +a );
if ( (+b - +a) > 86400000) {
sortedValue[++k] = []
}
return 1;
});
sortedValue.sort( function ( a,b ){
return a.length > b.length ? -1: 1;
});

This requires help from a function to test if two dates are in the same week. The following goes over the set of time values provided in an array and puts the first value into an array within the array. For each subsequent value, it tests if it's in the same week as the first value in each array within the outer array.
If it's in the same week as the first value in any existing array, it's pushed into that array. Otherwise, it's put in a new array and pushed into the outer array.
There may be a neater way to implement the algorithm, but I'll leave that for others.
Due to time zone differences, they are adjusted to the host time zone based on the original time values representing noon in the source time zone.
// Given 2 dates, return true if they are in the same week (Mon to Sun).
// Otherwise, return false
function sameWeek(a, b){
var e = new Date(+a);
// Week starts at 00:00:00.000 on Monday on or before date
var s = new Date(e.setDate(e.getDate() - ((e.getDay()||7) -1)));
s.setHours(0,0,0,0);
// Week ends at 23:59:59.999 the following Sunday
e.setDate(e.getDate() + 6);
e.setHours(23,59,59,999);
// Test b and return value
return b >= s && b <= e;
}
// Given time value for UTC-0400, adjust to same date and time
// in local time zone and return a date
function adjust(n) {
var d = new Date(n);
d.setMinutes(d.getMinutes() - 240 + d.getTimezoneOffset());
return d;
}
var result = [1491408000000,1491494400000,1491753600000,1493222400000,1493308800000,1493568000000
].reduce(function(acc, n) {
var d = adjust(n);
var used;
if (acc.length != 0) {
used = acc.some(function(arr) {
if (sameWeek(adjust(arr[0]), d)) {
arr.push(n);
return true;
}
});
}
if (!used || acc.length == 0) {
acc.push([n]);
}
return acc;
},[]);
// Result array
console.log(result);
// Printed as date strings adjusted to same host local time
result.forEach(arr => {
arr.forEach(n => console.log(adjust(n).toString()))
console.log('\n');
});

Manipulation of timestamps is a pain. JavaScript has a built-in Date type, as you know, and I would suggest you use it. Date#getUTCDay returns the day of the week as an integer (for reference, 4 is Friday, or the day before a weekend), while Date#setUTCDate and Date#getUTCDate together allow you to adjust the date in day increments (and have it overflow/underflow to the next/previous month). Thus, to determine whether a timestamp b follows "sequentially" (excluding weekends) after a, you can use:
function sequential (a, b) {
a = new Date(a)
return a.setUTCDate(a.getUTCDate() + (a.getUTCDay() === 4 ? 3 : 1)) === b
}
Grouping is just an exercise after that; the code above contains all of the real logic behind this solution.
Example Snippet
var dates = [
1491408000000,
1491494400000,
1491753600000,
1493222400000,
1493308800000,
1493568000000
]
function sequential (a, b) {
a = new Date(a)
return a.setUTCDate(a.getUTCDate() + (a.getUTCDay() === 4 ? 3 : 1)) === b
}
function groupSequential(dates) {
if (dates.length < 2) return [dates.slice()]
dates.sort(function(a, b) { return a - b })
var result = [], group
for (var i = 0; i < dates.length; i++) {
sequential(dates[i - 1], dates[i]) || result.push(group = [])
group.push(dates[i])
}
return result
}
console.log(groupSequential(dates))

regex a string, convert to number and match condition

I have this string:
002 2.0 (100aa) 95-97
I then want regex the 95-97 portion of it and paste it with relevant two numbers so I get a year.
In example, 96-97 should become 1995-1997, but 00-05 should become 2000-2005 (all numbers between 0 and 16 should be pasted with 20, but all other numbers with 19).
Then, when I have i.e. 1995-1997 I want to check if a year (i.e. 1996) is present inside 1995-1997 interval or not, and return a bolean.
How would one wright such code?
Best Regards

You could use the callback variant of replace:
function parseString(str) {
function padYear(year) {
return year < 30 ? 2000+year :
year < 100 ? 1900+year : year;
}
var result = {};
result.hasCurrentYear = false;
result.str = str.replace(/(\d\d)-(\d\d)$/g, function (match, yr1, yr2) {
yr1 = padYear(+yr1);
yr2 = padYear(+yr2);
var yrNow = (new Date).getFullYear();
result.hasCurrentYear = yrNow >= yr1 && yrNow <= yr2;
return yr1 + '-' + yr2;
});
return result;
}
var str = '002 2.0 (100aa) 95-16';
console.log(parseString(str));
Note that I made the split at year 30, as the solution will become outdated soon if you use 16 as split year.

I suppose there's a much simpler way to check if a certain year is in "range".The solution using String.split, Array.map functions and Number constructor:
var str = "002 2.0 (100aa) 95-97";
function checkYearInRange(str, year) {
year = Number(year);
var range = str.split(" ").pop().split('-').map((v) => Number((Number(v) > 16)? "19"+v : "20"+v));
return (range[0] <= year && year <= range[1]);
}
console.log(checkYearInRange(str, "1996")); // true
console.log(checkYearInRange(str, "2015")); // false

Check whether quarters are in sequential order using jQuery

I am having quarter list.
var quarters = new Array();
quarters.push("Q1 2014");
quarters.push("Q2 2014");
quarters.push("Q4 2014");
quarters.push("Q1 2015");
Here quarters are not in sequence. "Q3 2014" is missing.
How to check whether these are in sequence or not using jquery?

Sort the array (you'll need a callback comparison function to pass to sort)
Loop through the array comparing the "current" entry against the previous, looking to see if it's exactly one quarter later
In both cases, you'll probably need something that parses the strings so you have a quarter number and a year, rather than a string combining them. The parsing is trivial enough that you can use regex for it:
var parts = str.match(/^Q(\d) (\d{4})$/);
...and then parts[1] is the quarter and parts[2] is the year.
I'm not usually a fan of providing all the code, but as there's now incorrect code kicking around the question:
var quarters = [
"Q1 2014",
"Q2 2014",
"Q4 2014",
"Q1 2015"
];
var prev, i, curr;
// Sort the quarters according to their quarter value (see `qval` below)
quarters.sort(function(a, b) {
return qval(a) - qval(b);
});
// Find gaps by starting at the beginning and comparing each entry
// to the one just in front of it
prev = qval(quarters[0]);
for (i = 1; i < quarters.length; ++i) {
curr = qval(quarters[i]);
if (curr !== prev + 1) {
console.log("Gap found between " + quarters[i - 1] + " and " + quarters[i]);
}
prev = curr;
}
// `qval` parses a quarter string ("Q2 2014", for instance) and returns a
// a number for the quarter: The year times four plus the quarter
// within the year (e.g., 8058 for Q2 2014). For easy comparison.
function qval(quarterString) {
var qv, parts;
parts = quarterString.match(/^Q(\d) (\d{4})$/);
if (!parts) {
throw "Invalid quarter string: '" + quarterString + "'";
}
qv = (parseInt(parts[2]) * 4) + parseInt(parts[1]);
return qv;
}
Live Copy