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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)

Keep count of read for each month in array of object

Suppose I have an array of object as:
const sampleArray = [{"read":true,"readDate":2021-01-15T18:21:34.059Z},
{"read":true,"readDate":2021-01-15T18:21:34.059Z},
{"read":true,"readDate":2021-02-15T18:21:34.059Z},
{"read":true,"readDate":2021-04-15T18:21:34.059Z},
{"read":true,"readDate":2021-12-15T18:21:34.059Z}]
I want to keep count of read for each month and where the month is missing it should give 0.
Expected O/P :
[2,1,0,1,0,0,0,0,0,0,0,12] => In jan -2 count, feb - 1 count, april - 1 count, dec - 1 count and rest months there is no read data.
For this I tried :
let invoiceInfoArray = [];
var d = new Date();
var n = d.getMonth();
for (let i = 0; i < sampleArray.length; i++) {
if (sampleArray[i].readDate.getMonth() + 1 == n) {
invoiceInfoArray.push(invoiceInfo[i])
}
}
Also I thought as if I check for each condition but this will also not be feasible as it will check for particular month and if not available it will automatically insert 0 for rest which is incorrect,
for (let i = 0; i < sampleArray.length; i++) {
if (sampleArray[i].readDate.getMonth() + 1 == 1) {
invoiceInfoArray.push(invoiceInfo[i])
} else if (sampleArray[i].readDate.getMonth() + 1 != 1) {
invoiceInfoArray.push(0)
} else if (sampleArray[i].readDate.getMonth() + 1 == 2) {
invoiceInfoArray.push(invoiceInfo[i])
} else if (sampleArray[i].readDate.getMonth() + 1 != 2) {
invoiceInfoArray.push(0)
}
}
I'm unable to form logic on how I can achieve my target such that I want to keep count of read for each month and where the month is missing it should give 0.
Expected O/P :
[2,1,0,1,0,0,0,0,0,0,0,1] => In jan -2 count, feb - 1 count, april - 1 count, dec - 1 count and rest months there is no read data.
Please let me know if anyone needs any further details. Any guidance will really be helpful.

Create a new array of 12 length and make the readDate as a Date object and get the month from getMonth.
You can create a new array with 12elements and prefilled with 0 as
const months = Array(12).fill(0);
// or
const months = new Array(12).fill(0);
read about Array, fill
const sampleArray = [{
read: true,
readDate: "2021-01-15T18:21:34.059Z"
},
{
read: true,
readDate: "2021-01-15T18:21:34.059Z"
},
{
read: true,
readDate: "2021-02-15T18:21:34.059Z"
},
{
read: true,
readDate: "2021-04-15T18:21:34.059Z"
},
{
read: true,
readDate: "2021-12-15T18:21:34.059Z"
},
];
const months = Array(12).fill(0);
// or
// const months = new Array(12).fill(0);
sampleArray.forEach((obj) => {
const month = new Date(obj.readDate).getMonth();
++months[month];
});
console.log(months);

Check If a given time(Only hours:minutes) lies betwenn two other different time?

I have 2 different times:
var shiftStartTime = "05:48";
var shiftEndTime = "14:29";
And i have another time which is selectedDate ="06:20"(this will change according datetimepicker selection), and i want to check if selectedDate should be between (shiftStartTime and shiftEndTime ).
Can anyone help in this?
Updated Code:
i have 6 different timespan like below
var shift1StartTime = "05:48";
var shift1EndTime = "14:18";
var shift2StartTime = "14:30";
var shift2EndTime = "22:29";
va
r shift3StartTime = "22:30";
var shift3EndTime = "05:47";
using all 6 timespan i want to check the if the given time is between (shift1StartTime and shift1EndTime) return shift1
Or
if the given time is between (shift2StartTime and shift2EndTime) return shift2
Or
if the given time is between (shift3StartTime and shift3EndTime) return shift3

Simply compare the strings like
var shiftStartTime = "05:48"; var shiftEndTime = "14:29";
shiftStartTime > shiftEndTime // false

Here is some JS that does this, although better formatted time would make it a lot easier
function findTotalTime(time) {
hours = parseInt(time.substring(0,2))
mins = parseInt(time.substring(3,5))
return (hours*60) + mins
}
startTime = findTotalTime(shiftStartTime)
endTime = findTotalTime(shiftEndTime)
selectedTime = findTotalTime(selectedDate)
if (selectedTime > startTime && selectedTime < endTime) {
// time is inbetween shifts
}

const date = new Date();
const shiftStartTime = '05:48';
const shiftEndTime = '14:29';
const selectedDate = '14:20';
const start = date.setHours(+shiftStartTime.split(':')[0], +shiftStartTime.split(':')[1], 0, 0);
const end = date.setHours(+shiftEndTime.split(':')[0], +shiftEndTime.split(':')[1], 0, 0);
const selected = date.setHours(+selectedDate.split(':')[0], +selectedDate.split(':')[1], 0, 0);
if (start < selected && selected < end) {
console.log(true);
} else {
console.log(false);
}

Alright, so you got three relative times as strings in the format HH:mm. I'm assuming that your times are given as 24h strings / military time, because otherwise, you'd need an A.M. / P.M. specifier.
It is always useful to have the data you are working with in a well-suited machine-readable format, so you could parse them into a simple object holding the hour and minute as numbers.
A function doing this could look like this.
function parseTimeStr(time) {
// The pattern of your input,
// allows spaces around the `:`
// and single-digit inputs like `8:00`
let re = /([0-9][0-9]?)\s*:\s*([0-9][0-9]?)/;
let result = re.exec(time.trim());
if (result === null) {
throw "No match"
}
let hour = parseInt(result[1], 10);
let minute = parseInt(result[2], 10);
/* handle out of range values here */
return { hour, minute };
}
Alright, so you have these objects now. How do you compare them? There's a pattern for that: Have a function returning whether the first argument is greater (1), equal (0), or less (-1) than the second.
Writing this is simple now that the time is an object:
function cmpDate(date1, date2) {
if (date1.hour > date2.hour) {
return 1;
} else if (date1.hour < date2.hour) {
return -1;
} else if (date1.minute > date2.minute) {
return 1;
} else if (date1.minute < date2.minute) {
return -1;
} else {
return 0;
}
}
Alright, now we can have a helper function checking if the first argument is in the closed interval defined by the last two arguments:
function isInShift(time, shiftStart, shiftEnd) {
// time is greater or equal shiftStart
// and less or equal shiftEnd
return cmpDate(time, shiftStart) !== -1 && cmpDate(time, shiftEnd) !== 1;
}
You can then finally make your comparison by calling isInShift(parseTimeStr(selectedTime), parseTimeStr(shiftStartTime), parseTimeStr(shiftEndTime)). This will return a boolean. You can easily extend this infrastructure for multiple shifts.
Be aware that both reality and your users can be more ... screwy than you'd expect.
The above code does not do error handling for invalid time inputs, neither does it account for overnight shifts, but these are details that you can easily work out, you just have to put some effort into thinking of them.

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;
}
}
})

How to sum values over a given date range

I'm using LocalStorage to save an array of Dates and Costs.
When I'm writing localStorage.getItem("todos"); into the console, the format will be like this:
"[{"due":"28/10/2017","task":"80"},{"due":"06/10/2017","task":"15"}]"
Where due is the Date, and TASK is the AMOUNT.
I managed to get the TOTAL of AMOUNTS by:
total: {
type: String,
value: () => {
var values = localStorage.getItem("todos");
if (values === undefined || values === null) {
return "0";
}
var data = JSON.parse(values);
var sum = 0;
data.forEach(function(ele){ sum+=Number(ele.task)}); return sum;
}
}
Now I'm trying to get the TOTAL of last 6 MONTHS.
I have no idea on how to approach this.
How should I be able to do this?

During your iteration you need to add a check to make sure the sum is only including values where the due date is within your range. If you can use a library like moment, this would greatly simplify your logic.
const data = [
{ due: '28/10/2017', task: 80 },
{ due: '06/10/2017', task: 15 },
{ due: '10/05/2000', task: 3000 }
];
const sixMonthsAgo = moment().subtract(6, 'months');
const total = data.reduce((acc, item) => {
const dueDate = moment(item.due, 'DD/MM/YYYY');
return acc + (dueDate.isAfter(sixMonthsAgo) ? item.task : 0);
}, 0);
console.log('total should equal 95: ', total);
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.19.1/moment.min.js"></script>

Here is a solution for your issue :
make a test in the forEach loop :
I've put 4 dates : 2 under 6 months and 2 older
The result is 80+15 = 95
// After JSON.parse
var todos=[{"due":"28/10/2017","task":"80"},{"due":"06/10/2017","task":"15"},{"due":"06/04/2017","task":"15"},{"due":"06/02/2017","task":"15"}];
var sum = 0;
var minDate = new Date();
var month = minDate.getMonth()+1-6; // get month minus 6 months
var year = minDate.getFullYear(); // get year
if(month < 1){ // if month is under January then change year
month+=6;
year-= 1;
}
minDate.setMonth(month); // Replace our min date with our - 6 m
minDate.setYear(year); // set year in case we have changed
todos.forEach(function(ele){
var arr = ele.due.split("/"); // split french string date into d,m,y
if(arr.length==3){
var dueDate = new Date(arr[2],arr[1],arr[0]); // get the task date
if(dueDate>minDate){ // if task is not to old then
sum+=parseInt(ele.task); // sum it
}
}
});
console.log(sum);