MongoDB $log10 Operator

Posted in mongoDB Tutorial

Updated on Oct 31, 2024

By Mari Selvan

👁️ 11 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In MongoDB's aggregation framework, the $log10 operator plays a significant role in performing logarithmic operations on numerical data. This operator allows users to compute the base-10 logarithm of a given number, facilitating various applications in data analysis and mathematical computations.

Let's delve into how the $log10 operator can be effectively utilized within MongoDB's aggregation pipelines.

💡 Syntax

The syntax for the $log10 method is straightforward:

syntax.js

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{ $log10: <expression> }

$log10: This operator signifies that the subsequent operation will compute the base-10 logarithm.
<expression>: This represents the numerical expression for which the logarithm will be calculated. It could be a field reference, a mathematical expression, or a value.

📝 Example

⌨️ Input

Consider a collection named data containing documents with fields value representing numerical values. Here are sample documents from the data collection:

Input

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[
  { "_id": ObjectId("609c26812e9274a86871bc6a"), "value": 100 },
  { "_id": ObjectId("609c26812e9274a86871bc6b"), "value": 1000 },
  { "_id": ObjectId("609c26812e9274a86871bc6c"), "value": 10000 }
]

🔄 Aggregation

Suppose we want to calculate the base-10 logarithm of the value field for each document. Here's how you can achieve this using the $log10 operator:

example.js

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db.data.aggregate([
  {
    $project: {
      log10Value: { $log10: "$value" }
    }
  }
])

🧩 Explanation

$project: This stage reshapes documents, including or excluding fields, or computing new values.
$log10: Computes the base-10 logarithm of the specified field (value in this case).

When discussing how the above aggregation works:

For the first document, the "value" is 100, and its base-10 logarithm is 2.
For the second document, the "value" is 1000, and its base-10 logarithm is 3.
For the third document, the "value" is 10000, and its base-10 logarithm is 4.

💻 Output

Now, let's take a look at the output generated by the aggregation pipeline:

Output

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{ "_id": ObjectId("609c26812e9274a86871bc6a"), "log10Value": 2 }
{ "_id": ObjectId("609c26812e9274a86871bc6b"), "log10Value": 3 }
{ "_id": ObjectId("609c26812e9274a86871bc6c"), "log10Value": 4 }

📚 Use Cases

Scaling Data:

The $log10 operator is useful for scaling down large numerical values, making them more manageable for analysis or visualization.
Decibel Calculations:

In fields such as acoustics or electronics, the $log10 operator facilitates computations involving decibels, which are logarithmic in nature.
Data Transformation:

Logarithmic transformations can be employed to normalize or adjust skewed data distributions, enhancing the effectiveness of statistical analyses.

🎉 Conclusion

The $log10 operator in MongoDB's aggregation framework provides a powerful mechanism for computing base-10 logarithms within aggregation pipelines. Whether you're scaling data, performing specialized calculations, or transforming numerical values, mastering the usage of $log10 empowers you to efficiently manipulate numerical data and extract meaningful insights from your datasets.

With its intuitive syntax and diverse applications, the $log10 operator proves to be a valuable asset for handling numerical data effectively within MongoDB. Incorporate it into your aggregation pipelines to unlock new dimensions of data analysis and gain deeper insights into your datasets.