How to parse data stored in an array

Question

I have a CSV file I am working with. I don't want to convert it to an object to have keys and values. I want to be able to create more arrays to store different values I.e Temperature Hum hours snowDepth etc All these will be arrays with 7 values

Right now, this is how the csv is stored in the data array

"11/28/2018 7:30,1128,-2.122,86.2,34.06,1.178,320.2,20.4"

"11/28/2018 7:45,1129,-2.325,85.6,34.54,1.771,325.5,30.72"

"11/28/2018 8:00,1130,-2.679,85.7,30.73,1.764,312.1,28.98"

"11/28/2018 8:15,1131,-2.872,88,34.55,1.073,306.6,25.65"

"11/28/2018 8:30,1132,-2.953,90.7,35.25,1.247,311.2,30.06"

"11/28/2018 8:45,1133,-3.064,93.3,35,1.449,312.6,30.13"

"11/28/2018 9:00,1134,-2.771,91.5,33.44,0.988,311,28.27" length: 7

the 1st col is the timestamp, 2nd is record number, 3rd is the temperature, 4th is the humidity and so on.

function get_Data(data) {
    "use strict";
    var fileData = new Array();
    data = data.split(/\r\n|\r|\n/);
    data = data.slice(Math.max(data.length - 7, 0));
    createGraph(data);
}

I want arrays like this

Tem = [-2.122, -2.325, -2.679, -2.872 ...]

hours = [7:30, 7:45, 8:00, 8:15 ...]

You don't really have to parse anything. You just have to split by comma. To create an array of the values of column i: values = arr.map(str => str.split(',')[i]). Lots of related questions: stackoverflow.com/search?q=%5Bjavascript%5D+parse+csv — Felix Kling
– Felix Kling, Commented Jan 16, 2019 at 23:35
Could you add every value? We have the first four, but in each row there are eight values. — Jack Bashford
– Jack Bashford, Commented Jan 16, 2019 at 23:42
yeah, the 5th is SnowDepth, 6th is WS_ms_S_WVT(speed) 7th is WindDir_D1_WVT and 8th is the SD — Chukas Ebuka
– Chukas Ebuka, Commented Jan 17, 2019 at 0:05

Jack Bashford · Accepted Answer · 2019-01-16 23:48:02Z

2

Simple - map and split for each comma, then look at the index for which item it should be:

var data = ["11/28/2018 7:30,1128,-2.122,86.2,34.06,1.178,320.2,20.4",
  "11/28/2018 7:45,1129,-2.325,85.6,34.54,1.771,325.5,30.72",
  "11/28/2018 8:00,1130,-2.679,85.7,30.73,1.764,312.1,28.98",
  "11/28/2018 8:15,1131,-2.872,88,34.55,1.073,306.6,25.65",
  "11/28/2018 8:30,1132,-2.953,90.7,35.25,1.247,311.2,30.06",
  "11/28/2018 8:45,1133,-3.064,93.3,35,1.449,312.6,30.13",
  "11/28/2018 9:00,1134,-2.771,91.5,33.44,0.988,311,28.27",
];

var items = {
  date: [],
  recordNumber: [],
  temperature: [],
  humidity: [],
  value5: [],
  value6: [],
  value7: [],
  value8: [],
};

Object.keys(items).forEach((key, index) => items[key].push(data.map(str => str.split(",")[index])));

console.log(items);

answered Jan 16, 2019 at 23:48

Jack Bashford

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Comments

RocketNuts · Accepted Answer · 2019-01-17 01:05:08Z

0

You're mixing up a few things. What's fileData doing (seems unused)? And slice isn't the right way to do this.

Instead, try:

function get_Data(csv) {
    csv = csv.replace(/[\r\n]+/gi,"\n"); // reduce line endings into single LF chars
    rows = csv.split("\n"); // split into array of rows
    var result = [];
    for (var i in rows) result.push(rows[i].split(",")); // split each row
    return result;
}

(edit) If you only the need the last X rows of the CSV data, use:

function get_Data(csv,lastNumRows) { // get only the last <lastNumRows> rows
    csv = csv.replace(/[\r\n]+/gi,"\n"); // reduce line endings into single LF chars
    rows = csv.split("\n").slice(-lastNumRows); // split into array of rows
    var result = [];
    for (var i in rows) result.push(rows[i].split(",")); // split each row
    return result;
}

edited Jan 17, 2019 at 1:05

answered Jan 16, 2019 at 23:58

RocketNuts

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3 Comments

Chukas Ebuka Over a year ago

That's true, I don't need the fileData. I wanted the last 7 rows of the file

RocketNuts Over a year ago

Right, now I see how you used slice. I edited my answer for getting only the last 7 rows.

RocketNuts Over a year ago

Oh but I also see I misread your original question, you actually need the columns (e.g. all temperatures or all humidities), not rows. My bad.

Alen.Toma · Accepted Answer · 2019-01-16 23:54:42Z

0

try this, it should work. i know the position of the data so it was easy to split and find the terms and date

var csv = document.getElementById("csvFile").innerHTML ;



function get_Data(data) {
    var result = {terms:[], hours:[] }
    var r = data.split(/\r\n|\r|\n/);

    r.forEach(function(element) {
    if (element !== "" && element.length>1){
      var term = element.split(",")[2]
      var date = new Date(element.split(",")[0])
      var hour =  date.getHours() + ":" + (date.getMinutes()<=9 ? "0" + date.getMinutes() : date.getMinutes());
      
      result.terms.push(term);
      result.hours.push(hour)
      }
    });
 return result;
} 

console.log( get_Data(csv))

<div id="csvFile" style="display:none;">
11/28/2018 7:30,1128,-2.122,86.2,34.06,1.178,320.2,20.4
11/28/2018 7:45,1129,-2.325,85.6,34.54,1.771,325.5,30.72
11/28/2018 8:00,1130,-2.679,85.7,30.73,1.764,312.1,28.98
11/28/2018 8:15,1131,-2.872,88,34.55,1.073,306.6,25.65
11/28/2018 8:30,1132,-2.953,90.7,35.25,1.247,311.2,30.06
11/28/2018 8:45,1133,-3.064,93.3,35,1.449,312.6,30.13
11/28/2018 9:00,1134,-2.771,91.5,33.44,0.988,311,28.27
</div>

answered Jan 16, 2019 at 23:54

Alen.Toma

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2 Comments

Chukas Ebuka Over a year ago

I don't want to do position because the records varies each time there is a new row. This will affect the values stored in an array. I don't know if that makes sense

Alen.Toma Over a year ago

hmm but @Jack Bashford did the same thing. my solution is like this becouse then you could control your data parsing. like hour for instead. but yah as you which

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