Determine the maximum value in an array that includes both numerical and non-numeric values

Question

Determine the maximum value in an array that includes both numerical and non-numeric values

My goal is to determine the maximum value for 15-minute data that I am extracting from a .csv file. Each row in the file represents 15-minutes of data from a different source identified by "ID" on a specific day indicated by "Date". However, there are unnecessary columns such as "Class", "Sample", and "Channel" that are not relevant to my analysis.

I initially considered using d3.group, but having five key values corresponding to the non-numeric attributes does not seem to be the most effective approach.

The format of the imported data is as follows:

[
  {
    "ID": "10D1012B",
    "Class": "R",
    "Sample": "135_OLD",
    "Channel": "1",
    "Date": "1/1/2019",
    "00:15": "0.48",
    "00:30": "0.6",
    "00:45": "0.896",
    "01:00": "0.712",
    "01:15": "1.12",
          ...
    "23:00": "0.48",
    "23:15": "0.6",
    "23:30": "0.624",
    "23:45": "0.552",
    "00:00": "0.704"
  },
  {
    "ID": "10D1040B",
    "Class": "R",
    "Sample": "135_OLD",
    "Channel": "1",
    "Date": "1/2/2019",
    "00:15": "1.016",
         ...
    "23:30": "0.632",
    "23:45": "0.72",
    "00:00": "0.776"
  }
]

To establish the chart scale, I need to compute the highest value within each row of data (identified by ID and Date). However, I am unsure about the appropriate method to exclude the non-numeric columns when determining the maximum value.

javascript d3.js

Answer 1

Answer №1

Two issues need to be addressed in your code: firstly, the d3.max function is traversing through different objects within the same array, when you actually want it to traverse through different values within the same object. Secondly, there are numerical values, like those for the "Channel" property, that should not be included. This makes the task more complex than simply identifying all numerical values in the properties.

To tackle this, I suggest creating a list of property names or keys that should be excluded from consideration:

const nonNeededKeys = ["ID", "Class", "Sample", "Channel", "Date"];

Then, utilize d3.max for all other keys within each object in the array:

data.forEach(function(row) {
  const keys = d3.keys(row).filter(function(d) {
    return nonNeededKeys.indexOf(d) === -1;
  });
  row.maxValue = d3.max(keys.map(function(d) {
    return +row[d]
  }))
});

In this approach, a new property named maxValue is created for each object.

A demo showcasing this method can be found below:

const data = [/* Data array goes here */];
// Rest of the script as shown
console.log(data)

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.7.0/d3.min.js"></script>

Subsequently, determining the maximum value across all objects becomes straightforward:

const maxValue = d3.max(data, function(d) {
    return d.maxValue;
});

Check out the snippet below to see the process in action:

const data = [/* Data array goes here */];
// Rest of the script as shown
const maxValue = d3.max(data, function(d) {
  return d.maxValue;
})
console.log(maxValue)

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.7.0/d3.min.js"></script>

Answer 2

Two issues need to be addressed in your code: firstly, the d3.max function is traversing through different objects within the same array, when you actually want it to traverse through different values within the same object. Secondly, there are numerical values, like those for the "Channel" property, that should not be included. This makes the task more complex than simply identifying all numerical values in the properties.

To tackle this, I suggest creating a list of property names or keys that should be excluded from consideration:

const nonNeededKeys = ["ID", "Class", "Sample", "Channel", "Date"];

Then, utilize d3.max for all other keys within each object in the array:

data.forEach(function(row) {
  const keys = d3.keys(row).filter(function(d) {
    return nonNeededKeys.indexOf(d) === -1;
  });
  row.maxValue = d3.max(keys.map(function(d) {
    return +row[d]
  }))
});

In this approach, a new property named maxValue is created for each object.

A demo showcasing this method can be found below:

const data = [/* Data array goes here */];
// Rest of the script as shown
console.log(data)

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.7.0/d3.min.js"></script>

Subsequently, determining the maximum value across all objects becomes straightforward:

const maxValue = d3.max(data, function(d) {
    return d.maxValue;
});

Check out the snippet below to see the process in action:

const data = [/* Data array goes here */];
// Rest of the script as shown
const maxValue = d3.max(data, function(d) {
  return d.maxValue;
})
console.log(maxValue)

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/5.7.0/d3.min.js"></script>

Determine the maximum value in an array that includes both numerical and non-numeric values

Answer №1

Similar questions

The unprojection of the vector in Threejs from this camera has not been defined

Unleashing the Power of Aurelia's HTML Attribute Binding

Is it possible to transfer data from javascript to php through ajax?

angular application developed using HTML, CSS, and JavaScript

Can you please explain the significance of the code "!!~this.roles.indexOf('*')" within the MEAN.io framework?

Is there a way for me to obtain the full error message after a failed fetch request?

Limiting the space character in a password field with regular expressions in JavaScript

I am attempting to retrieve JSON data in JavaScript but am seeing a null response in the action class

I am looking to modify the brand name that is being displayed in a while loop using AJAX. The information is stored in an input field of type "text

Execute the setTimeout function when scrolling occurs

Achieving the sorting of empty data to be at the end using jQuery

"Exploring Mocha and Chai: Tips for Generating a Comprehensive List of Errors in Test Cases

Navigating through an empty array while implementing a combination of map and filter in react.js

Accessing this.href from the ASP.NET code behind using Javascript

Unlocking the power of executing Node.js functions with JavaScript

Tips for displaying four distinct pages with d3js graphs in four different divs on a single webpage using jQuery or JavaScript

What is the best way to shorten text in React/CSS or Material UI based on the line height multiples?

Using jQuery to implement tiered radio buttons styled with Bootstrap

Tips for managing player rounds updates

Each loop in the forEach function triggers the mouseup event