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sales data / JS

I have a sales data for a couple of years in an array:
var= ['Jan-2019',325678], ['feb-2019', 456789], ['Mar-2019',-12890],.....['Dec-2021', 987460]
1 -want to calculate the net total amount of profit/losses over the entire period.
2- Average of the (changes) in profit/losses over the entire period - track the total change in profits from month to month and find the average(total/number of months)
3 - greatest increase in profit (month and amount)over the whole period
4 - greatest decrease3in profit (month and amount)over the whole period
Tried to solve number 1 using :
`
const profitMonths = data.filter(el => el[1] > 0);
console.log("Total:", profitMonths.map(el => el[1]).reduce((a, b) => a + b));
console.log;
`
but the sum I am getting is different from what excel and calculator is giving me.
I will appreciate some help here

Not sure what is the format of your original data records for each of the months. I assumed that your data format is like below. But you could get the sum of each months growth or loss (earnings) like this and also get what you were trying as well (profit months total sales):
const data = [
['Jan-2019', 325678],
['Feb-2019', 456789],
['Mar-2019', -12890],
];
const earningsArray = data.map((el) => el[1]);
const profitMonths = data.filter((el) => el[1] > 0);
const salesOnProfitMonths = profitMonths
.map((el) => el[1])
.reduce((accVal, curVal) => accVal + curVal, 0);
const avgOfProfitAndLoss =
earningsArray.reduce((accVal, curVal) => accVal + curVal, 0) / data.length; // get the average of all total and losses
const maxMonth = {
monthName: '',
profit: 0,
};
const minMonth = {
monthName: '',
profit: 0,
};
data.forEach((month) => {
if (month[1] > maxMonth.profit) {
maxMonth.monthName = month[0];
maxMonth.profit = month[1];
}
if (month[1] < minMonth.profit) {
minMonth.monthName = month[0];
minMonth.profit = month[1];
}
return { maxMonth, minMonth };
});
console.log('Total sale of profit months: ', salesOnProfitMonths);
console.log('Total average : ', avgOfProfitAndLoss);
console.log('The month with max profit is : ', maxMonth);
console.log('The month with min profit is : ', minMonth);

Using .reduce() you can actually build an object to the returned based on all of the data from your original array.
const data = [['Jan-2019', 325678], ['feb-2019', 456789], ['Mar-2019',-12890], ['Dec-2021', 987460]]
let result = data.reduce((a, b, i) => {
let d = (i > 1) ? a : {total: a[1], average: a[1], sumChange: 0, lastMonth: a[1], increase: a, decrease: a},
change = b[1] - d.lastMonth
d.total += b[1]
d.sumChange += change
d.lastMonth = b[1]
d.average = d.sumChange / i
d.increase = (d.increase[1] > change) ? d.increase : [b[0], change]
d.decrease = (d.decrease[1] < change) ? d.decrease : [b[0], change]
return d
})
console.log(result) // Return the full object
console.log(result.total) // Only return one value, the total
Based on the array/input you provided, this should provide a net total, average profit/loss, highest increase from the previous month, and highest decrease from the previous month.
EDIT
I had to make a few adjustments after getting some clarification. But this again should return a single object that holds values for everything requested by OP. (the sumChange and lastMonth values are only there to help with the .reduce() function month over month)
NOTES
Just for clarity as OP claimed they were not getting the right values, here is a breakdown based on the provided data:
Date
Sales
Change
Jan-2019
$325,678
N/A
Feb-2019
$456,789
$131,111
Mar-2019
-$12,890
-$469,679
Dec-2021
$987,460
$1,000,350
Based on this input, calculated manually:
The "Average of the (changes) in profit/losses over the entire period" is $220,594 (($131,111 + $469,679 + $1,000,350) / 3).
The "greatest increase in profit (month and amount)over the whole period" would be Dec-2021 with a $1,000,350 increase.
And the "greatest decrease in profit (month and amount)over the whole period" would be Mar-2019 with -$469,679.
This is exactly what my .reduce() does produce, so I'm not sure what actual input or output OP is getting (or how they are applying this to their code/data).

Adding years to array of dates

if by end of the period person is greater than 18 i want childEndDate to be the date of person's date when he/she will become 18 years old.
in my else if statement i am using date-fns library to add 18 years to dates i have in my this.childBirthDate array. but returned output is wrong: ["1988-01-01T00:00:02.012Z", "1988-01-01T00:00:02.010Z", "2031-11-08T13:24:43.704Z"]
output i want returned is: ['2030-02-16T20:00:00.000Z', '2028-05-19T20:00:00.000Z', 2031-11-08T13:24:43.704Z]
here is my stackblitz
this.childBirthDate = [
'2012-02-16T20:00:00.000Z',
'2010-05-19T20:00:00.000Z',
'2016-05-19T20:00:00.000Z',
];
//enddate
const endYear = date.getFullYear() + 10;
date.setFullYear(endYear);
this.endDate = date.toISOString();
this.childBirthDate.forEach((element) => {
const birthYear = element.substring(0, 4);
this.childbirthYear.push(+birthYear);
});
const periodEndYear = +this.endDate.substring(0, 4);
// calculate child endDate
this.childbirthYear.forEach(element => {
if (periodEndYear - element < 18) {
this.childEndDate = this.endDate;
} else if (periodEndYear - element >= 18) {
this.childEndDate = addYears(new Date(element), 18).toISOString();
}
this.final.push(this.childEndDate);
});
console.log(this.final)
this.personalInfo = {
personalInfoId: 0,
underageChildInfo: this.data.underageChildInfo?.map((i, index) => ({
firstName: i.name,
endDate: this.final[index],
})),
};

I think your logic to get the end date is reproducing what you want. However, I think your code may be hard to follow due to all the extra variables.
If you remove the foreach loops in favor of some map operators, your code will log the dates you are looking to get.
e.g.
// in ngOnInit
this.finalDates = this.childBirthDate.map(date => {
return this.calculateDate(date);
});
// outputs ["2030-02-16T20:00:00.000Z", "2028-05-19T20:00:00.000Z", "2031-11-08T14:28:01.761Z"]
console.log(this.finalDates);
// custom method on the class
calculateDate(date: string): string {
const periodEndYear = +this.endDate.substring(0, 4);
const year = parseInt(date.substring(0, 4), 10); // get a number from string
if (periodEndYear - year < 18) {
return this.endDate;
} else if (periodEndYear - year >= 18) {
return addYears(new Date(date), 18).toISOString();
}
return date;
}
here is a fork of your blitz

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);

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);

Separate data from datahash

I am working on a Dimple/D3 chart that plots missing days' data as 0.
date fruit count
2013-12-08 12:12 apples 2
2013-12-08 12:12 oranges 5
2013-12-09 16:37 apples 1
<- oranges inserted on 12/09 as 0
2013-12-10 11:05 apples 6
2013-12-10 11:05 oranges 2
2013-12-10 20:21 oranges 1
I was able to get nrabinowitz's excellent answer to work, nearly.
My data's timestamp format is YYYY-MM-DD HH-MM, and the hashing + D3.extent time interval in days results in 0-points every day at midnight, even if there is data present from later in the same day.
An almost-solution I found was to use .setHours(0,0,0,0) to discard the hours/minutes, so that all data would appear to be from midnight:
...
var dateHash = data.reduce(function(agg, d) {
agg[d.date.setHours(0,0,0,0)] = true;
return agg;
}, {});
...
This works as expected when there is just 1 entry per day everyday, BUT on days when there are multiple entries the values are added together. So in the data above on 12/10: apples: 6 , oranges: 3.
Ideally (in my mind) I would separate the plotting data from the datehash, and on the hash discard hours/minutes. This would compare the midnight-datehash with the D3 days interval, fill in 0s at midnight on days with missing data, and then plot the real points with hours/minutes intact.
I have tried data2 = data.slice() followed by setHours, but the graph still gets the midnight points:
...
// doesn't work, original data gets converted
var data2 = data.slice();
var dateHash = data2.reduce(function(agg, d) {
agg[d.date.setHours(0,0,0,0)] = true;
return agg;
}, {});
...
Props to nrabinowitz, here is the adapted code:
// get the min/max dates
var extent = d3.extent(data, function(d) { return d.date; }),
// hash the existing days for easy lookup
dateHash = data.reduce(function(agg, d) {
agg[d.date] = true;
// arrr this almost works except if multiple entries per day
// agg[d.date.setHours(0,0,0,0)] = true;
return agg;
}, {}),
headers = ["date", "fruit", "count"];
// make even intervals
d3.time.days(extent[0], extent[1])
// drop the existing ones
.filter(function(date) {
return !dateHash[date];
})
// fruit list grabbed from user input
.forEach(function(date) {
fruitlist.forEach(function(fruits) {
var emptyRow = { date: date };
headers.forEach(function(header) {
if(header === headers[0]) {
emptyRow[header] = fruits;}
else if(header === headers[1]) {
emptyRow[header] = 0;};
// and push them into the array
data.push(emptyRow);
});
// re-sort the data
data.sort(function(a, b) { return d3.ascending(a.date, b.date); });
(I'm not concerned with 0-points in the hour-scale, just the dailies. If the time.interval is changed from days to hours I suspect the hash and D3 will handle it fine.)
How can I separate the datehash from the data? Is that what I should be trying to do?

I can't think of a smooth way to do this but I've written some custom code which works with your example and can hopefully work with your real case.
var svg = dimple.newSvg("#chartContainer", 600, 400),
data = [
{ date : '2013-12-08 12:12', fruit : 'apples', count : 2 },
{ date : '2013-12-08 12:12', fruit : 'oranges', count : 5 },
{ date : '2013-12-09 16:37', fruit : 'apples', count : 1 },
{ date : '2013-12-10 11:05', fruit : 'apples', count : 6 },
{ date : '2013-12-10 11:05', fruit : 'oranges', count : 2 },
{ date : '2013-12-10 20:21', fruit : 'oranges', count : 1 }
],
lastDate = {},
filledData = [],
dayLength = 86400000,
formatter = d3.time.format("%Y-%m-%d %H:%M");
// The logic below requires the data to be ordered by date
data.sort(function(a, b) {
return formatter.parse(a.date) - formatter.parse(b.date);
});
// Iterate the data to find and fill gaps
data.forEach(function (d) {
// Work from midday (this could easily be changed to midnight)
var noon = formatter.parse(d.date).setHours(12, 0, 0, 0);
// If the series value is not in the dictionary add it
if (lastDate[d.fruit] === undefined) {
lastDate[d.fruit] = formatter.parse(data[0].date).setHours(12, 0, 0, 0);
}
// Calculate the days since the last occurance of the series value and fill
// with a line for each missing day
for (var i = 1; i <= (noon - lastDate[d.fruit]) / dayLength - 1; i++) {
filledData.push({
date : formatter(new Date(lastDate[d.fruit] + (i * dayLength))),
fruit : d.fruit,
count : 0 });
}
// update the dictionary of last dates
lastDate[d.fruit] = noon;
// push to a new data array
filledData.push(d);
}, this);
// Configure a dimple line chart to display the data
var chart = new dimple.chart(svg, filledData),
x = chart.addTimeAxis("x", "date", "%Y-%m-%d %H:%M", "%Y-%m-%d"),
y = chart.addMeasureAxis("y", "count"),
s = chart.addSeries("fruit", dimple.plot.line);
s.lineMarkers = true;
chart.draw();
You can see this working in a fiddle here:
http://jsfiddle.net/LsvLJ/