Can anyone help me on how to sum and then divide by the length of the array to get the average between dynamic multiple array of objects in javascript, the structure of my data as below. (example two array of objects, but might be more then 2 array of object)
"result": [
{
"id": "ioimall",
"color": "hsla(147, 47%, 55%, 1)",
"data": [
{
"x": "2023-04-01",
"y": 13.3202
},
{
"x": "2023-04-02",
"y": 11.8434
},
{
"x": "2023-04-03",
"y": 17.2365
},
{
"x": "2023-04-04",
"y": 13.2256
},
{
"x": "2023-04-05",
"y": 23.9547
},
{
"x": "2023-04-06",
"y": 17.1793
},
{
"x": "2023-04-07",
"y": 15.776
},
{
"x": "2023-04-08",
"y": 11.3356
},
{
"x": "2023-04-09",
"y": 6.6018
},
{
"x": "2023-04-10",
"y": 4.3196
},
{
"x": "2023-04-11",
"y": 4.8547
},
{
"x": "2023-04-12",
"y": 4.1935
},
{
"x": "2023-04-13",
"y": 4.6628
},
{
"x": "2023-04-14",
"y": 5.9717
},
{
"x": "2023-04-15",
"y": 3.8766
},
{
"x": "2023-04-16",
"y": 3.6379
},
{
"x": "2023-04-17",
"y": 4.7511
},
{
"x": "2023-04-18",
"y": 5.2891
},
{
"x": "2023-04-19",
"y": 4.7904
},
{
"x": "2023-04-20",
"y": 7.5441
},
{
"x": "2023-04-21",
"y": 191.0336
},
{
"x": "2023-04-22",
"y": 0
},
{
"x": "2023-04-23",
"y": 0
},
{
"x": "2023-04-24",
"y": 0
},
{
"x": "2023-04-25",
"y": 0
},
{
"x": "2023-04-26",
"y": 0
},
{
"x": "2023-04-27",
"y": 0
},
{
"x": "2023-04-28",
"y": 0
},
{
"x": "2023-04-29",
"y": 0
},
{
"x": "2023-04-30",
"y": 0
}
]
},
{
"id": "mytown",
"color": "hsla(221, 79%, 74%, 1)",
"data": [
{
"x": "2023-04-01",
"y": 4.8123
},
{
"x": "2023-04-02",
"y": 5.5642
},
{
"x": "2023-04-03",
"y": 5.2656
},
{
"x": "2023-04-04",
"y": 8.7167
},
{
"x": "2023-04-05",
"y": 5.3078
},
{
"x": "2023-04-06",
"y": 4.7283
},
{
"x": "2023-04-07",
"y": 4.1322
},
{
"x": "2023-04-08",
"y": 5.1783
},
{
"x": "2023-04-09",
"y": 5.2504
},
{
"x": "2023-04-10",
"y": 6.7794
},
{
"x": "2023-04-11",
"y": 5.0806
},
{
"x": "2023-04-12",
"y": 4.9803
},
{
"x": "2023-04-13",
"y": 4.3914
},
{
"x": "2023-04-14",
"y": 5.4071
},
{
"x": "2023-04-15",
"y": 4.939
},
{
"x": "2023-04-16",
"y": 4.4732
},
{
"x": "2023-04-17",
"y": 5.0562
},
{
"x": "2023-04-18",
"y": 5.0911
},
{
"x": "2023-04-19",
"y": 4.8266
},
{
"x": "2023-04-20",
"y": 23.4864
},
{
"x": "2023-04-21",
"y": 1185.7143
},
{
"x": "2023-04-22",
"y": 0
},
{
"x": "2023-04-23",
"y": 0
},
{
"x": "2023-04-24",
"y": 0
},
{
"x": "2023-04-25",
"y": 0
},
{
"x": "2023-04-26",
"y": 0
},
{
"x": "2023-04-27",
"y": 0
},
{
"x": "2023-04-28",
"y": 0
},
{
"x": "2023-04-29",
"y": 0
},
{
"x": "2023-04-30",
"y": 0
}
]
}
],
what I would like to sum/reduce is the key y: (value1 + value2)/length (to get the average) inside the key data
Expected result as below:
"result": [
{
"id": "average",
"color": "hsla(147, 47%, 55%, 1)",
"data": [
{
"x": "2023-04-01",
"y": 9.06
},
{
"x": "2023-04-02",
"y": 8.70
},
{
"x": "2023-04-03",
"y": 11.25
},
{
"x": "2023-04-04",
"y": 10.97
},
{
"x": "2023-04-05",
"y": 14.63
},
{
"x": "2023-04-06",
"y": 10.95
},
{
"x": "2023-04-07",
"y": 9.95
},
{
"x": "2023-04-08",
"y": 8.25
},
{
"x": "2023-04-09",
"y": 5.92
},
{
"x": "2023-04-10",
"y": 5.54
},
{
"x": "2023-04-11",
"y": 4.96
},
{
"x": "2023-04-12",
"y": 4.58
},
{
"x": "2023-04-13",
"y": 4.52
},
{
"x": "2023-04-14",
"y": 5.68
},
{
"x": "2023-04-15",
"y": 4.40
},
{
"x": "2023-04-16",
"y": 4.05
},
{
"x": "2023-04-17",
"y": 4.90
},
{
"x": "2023-04-18",
"y": 5.19
},
{
"x": "2023-04-19",
"y": 4.80
},
{
"x": "2023-04-20",
"y": 15.51
},
{
"x": "2023-04-21",
"y": 688.37
},
{
"x": "2023-04-22",
"y": 0
},
{
"x": "2023-04-23",
"y": 0
},
{
"x": "2023-04-24",
"y": 0
},
{
"x": "2023-04-25",
"y": 0
},
{
"x": "2023-04-26",
"y": 0
},
{
"x": "2023-04-27",
"y": 0
},
{
"x": "2023-04-28",
"y": 0
},
{
"x": "2023-04-29",
"y": 0
},
{
"x": "2023-04-30",
"y": 0
}
]
}
],
>Solution :
If you always have all x values represented in each of the data arrays:
Start with the first data array, and look at each x value. Then, locate all matching objects with that x value. Use reduce to add them together to compute the average.
const arr = [{"id":"ioimall","color":"hsla(147, 47%, 55%, 1)","data":[{"x":"2023-04-01","y":13.3202},{"x":"2023-04-02","y":11.8434},{"x":"2023-04-03","y":17.2365},{"x":"2023-04-04","y":13.2256},{"x":"2023-04-05","y":23.9547},{"x":"2023-04-06","y":17.1793},{"x":"2023-04-07","y":15.776},{"x":"2023-04-08","y":11.3356},{"x":"2023-04-09","y":6.6018},{"x":"2023-04-10","y":4.3196},{"x":"2023-04-11","y":4.8547},{"x":"2023-04-12","y":4.1935},{"x":"2023-04-13","y":4.6628},{"x":"2023-04-14","y":5.9717},{"x":"2023-04-15","y":3.8766},{"x":"2023-04-16","y":3.6379},{"x":"2023-04-17","y":4.7511},{"x":"2023-04-18","y":5.2891},{"x":"2023-04-19","y":4.7904},{"x":"2023-04-20","y":7.5441},{"x":"2023-04-21","y":191.0336},{"x":"2023-04-22","y":0},{"x":"2023-04-23","y":0},{"x":"2023-04-24","y":0},{"x":"2023-04-25","y":0},{"x":"2023-04-26","y":0},{"x":"2023-04-27","y":0},{"x":"2023-04-28","y":0},{"x":"2023-04-29","y":0},{"x":"2023-04-30","y":0}]},{"id":"mytown","color":"hsla(221, 79%, 74%, 1)","data":[{"x":"2023-04-01","y":4.8123},{"x":"2023-04-02","y":5.5642},{"x":"2023-04-03","y":5.2656},{"x":"2023-04-04","y":8.7167},{"x":"2023-04-05","y":5.3078},{"x":"2023-04-06","y":4.7283},{"x":"2023-04-07","y":4.1322},{"x":"2023-04-08","y":5.1783},{"x":"2023-04-09","y":5.2504},{"x":"2023-04-10","y":6.7794},{"x":"2023-04-11","y":5.0806},{"x":"2023-04-12","y":4.9803},{"x":"2023-04-13","y":4.3914},{"x":"2023-04-14","y":5.4071},{"x":"2023-04-15","y":4.939},{"x":"2023-04-16","y":4.4732},{"x":"2023-04-17","y":5.0562},{"x":"2023-04-18","y":5.0911},{"x":"2023-04-19","y":4.8266},{"x":"2023-04-20","y":23.4864},{"x":"2023-04-21","y":1185.7143},{"x":"2023-04-22","y":0},{"x":"2023-04-23","y":0},{"x":"2023-04-24","y":0},{"x":"2023-04-25","y":0},{"x":"2023-04-26","y":0},{"x":"2023-04-27","y":0},{"x":"2023-04-28","y":0},{"x":"2023-04-29","y":0},{"x":"2023-04-30","y":0}]}]
console.log({
id: 'average',
data: arr[0].data.map(({x})=>({
x,
y: arr.map(i => i.data.find(j => j.x===x).y)
.reduce((a,c) => a+c) / arr.length
})
)}
)