Reduce multiple matrixes to single matrix and perform value addition

I have a list (array) of matrixes in a data structure like so:

const data = [

matrix:
rows:
ROW1:
cols:
COL1: "4",
COL2: "2"

,
ROW2:
cols:
COL1: "1",
COL2: "4"

,
ROW3:
cols:
COL1: "2",
COL2: "1"



,
,

matrix:
rows:
ROW1:
cols:
COL1: "1",
COL2: "6"

,
ROW2:
cols:
COL1: "2",
COL2: "3"

,
ROW3:
cols:
COL1: "5",
COL2: "2"





];


I would like to sum up the values defined at the same ROW:COL pairs and end up with a single matrix like so:

const newMatrix =
rows:
ROW1:
cols:
COL1: "5",
COL2: "8"

,
ROW2:
cols:
COL1: "3",
COL2: "7"

,
ROW3:
cols:
COL1: "7",
COL2: "3"



;


I do not know beforehand how many matrixes I might receive in the data array. I also do not know beforehand how many rows and columns I receive.

I started off by calling reduce() on the data but got stuck because I cannot think of a way of finding and then summing up the data at ROW:COL pairs of the same name.

const newMatrix = data.reduce(( accumulator, current ) =>
let newMatrix;
// ...???
// find? forEach? Object.entries? for loops? maps inside maps?
// Everything I tried failed
return newMatrix;
);


I have also messed around with forEach(), Object.values(), find() and all sorts of for loops inside other loops but I keep ending up in some kind of brain loop myself.

I realise this might not be enough to work yet but I'm new at programming and don't know where to go next.

I have been stuck for 2.5 days now on this very problem so even if no straight up solution is offered I would appreciate any tips or guidance in the right direction.

Unfortunately I have no peers who I can ask for help.

Thank you.

3 Answers
3

Since the number of row and column is not static, a recursive function will be applied to get the sum without assuming column or row property name.

const data = [
matrix:
rows:
ROW1:
cols:
COL1: "4",
COL2: "2"

,
ROW2:
cols:
COL1: "1",
COL2: "4"

,
ROW3:
cols:
COL1: "2",
COL2: "1"



,
,

matrix:
rows:
ROW1:
cols:
COL1: "1",
COL2: "6"

,
ROW2:
cols:
COL1: "2",
COL2: "3"

,
ROW3:
cols:
COL1: "5",
COL2: "2"





];

var result = ;
var sum = function(from, to)

var keys = Object.keys(from);

for (let i = 0; i < keys.length; i++)
if (to[keys[i]] === undefined)
to[keys[i]] = from[keys[i]];
else
if (typeof from[keys[i]] === "object")
sum(from[keys[i]], to[keys[i]])
else
to[keys[i]] = parseInt(from[keys[i]]) + parseInt(to[keys[i]]);



;


for (index in data)
sum(data[index], result);


console.log(result);

You have to do it in reverse, meaning loop for columns, then rows, then matrices. Following code has detailed solution.

function sumMatrices(data)



const data = [

matrix:
rows:
ROW1:
cols:
COL1: "4",
COL2: "2"

,
ROW2:
cols:
COL1: "1",
COL2: "4"

,
ROW3:
cols:
COL1: "2",
COL2: "1"



,
,

matrix:
rows:
ROW1:
cols:
COL1: "1",
COL2: "6"

,
ROW2:
cols:
COL1: "2",
COL2: "3"

,
ROW3:
cols:
COL1: "5",
COL2: "2"





];

sumMatrices(data);

You can try looping through the keys of your object and build your final result adding the values as you go.

const data = [

matrix:
rows:
ROW1:
cols:
COL1: "4",
COL2: "2"

,
ROW2:
cols:
COL1: "1",
COL2: "4"

,
ROW3:
cols:
COL1: "2",
COL2: "1"



,
,

matrix:
rows:
ROW1:
cols:
COL1: "1",
COL2: "6"

,
ROW2:
cols:
COL1: "2",
COL2: "3"

,
ROW3:
cols:
COL1: "5",
COL2: "2"





];

const sumMatrices = (array) =>

const summed = matrix: rows: ;

array.forEach((item) =>

Object.keys(item.matrix.rows).forEach((row) =>

if (!summed.matrix.rows[row]) summed.matrix.rows[row] = cols: ;

Object.keys(item.matrix.rows[row].cols).forEach((col) =>

if (!summed.matrix.rows[row].cols[col]) summed.matrix.rows[row].cols[col] = 0;

summed.matrix.rows[row].cols[col] += +item.matrix.rows[row].cols[col];
);
);
);

return summed;
;

console.log(sumMatrices(data));

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