Benchmark: atan2 vs acos - MeasureThat.net

Script Preparation code:

var N = 1000000;
var x = new Float32Array(N);
var y = new Float32Array(N);

for (var i = 0; i < N; ++i) {
    x[i] = 100 * Math.random();
    y[i] = 100 * Math.random();
}

Tests:

acos
var fn = Math.acos; for (var i = 0; i < N; ++i) { fn(x[i]/Math.sqrt(x[i]*x[i]+y[i]*y[i])); }
atan2
var fn = Math.atan; for (var i = 0; i < N; ++i) { fn(y[i], x[i]); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
acos
atan2

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark compares the performance of two functions: `Math.acos` and `Math.atan2`. The goal is to evaluate which function is faster when used in a specific numerical calculation.

**Options Compared**

Two options are compared:

1. **Using `Math.acos`**: This option uses the `acos` (inverse cosine) function, which takes only one argument.
2. **Using `Math.atan2`**: This option uses the `atan2` (inverse tangent, y/x) function, which takes two arguments.

**Pros and Cons**

* **Using `Math.acos`**:
	+ Pros: `acos` is generally a simple and fast function to compute. However, it's not designed for general-purpose inverse trigonometric calculations, so it may not be as accurate or robust as other options.
	+ Cons: It only takes one argument, which might limit its applicability in certain scenarios.
* **Using `Math.atan2`**:
	+ Pros: `atan2` is a more versatile and accurate function for inverse trigonometric calculations. However, it's also slightly slower than `acos` due to the additional complexity of handling both y/x coordinates.
	+ Cons: It requires two arguments (y/x), which might be less convenient in some cases.

**Library**

The benchmark uses the `Math` library, which is a built-in JavaScript library that provides various mathematical functions. In this case, it's used for the `acos` and `atan2` functions.

**Special JS Feature or Syntax**

This benchmark doesn't use any special JavaScript features or syntax beyond what's standard in modern JavaScript. However, it does rely on the `for` loop and the `Float32Array` constructor, which are both widely supported.

**Other Alternatives**

There are a few alternative approaches to implementing inverse trigonometric calculations:

1. **Using other libraries**: Other libraries like `mathjs`, `numjs`, or `fast-math` might provide more efficient or accurate implementations of these functions.
2. **Implementing from scratch**: One could write their own implementation of the `acos` and `atan2` functions in JavaScript, which would allow for more fine-grained control over performance and accuracy.
3. **Using SIMD instructions**: Modern CPUs often have SIMD (Single Instruction, Multiple Data) instructions that can accelerate certain mathematical operations. Implementing these functions using SIMD could potentially lead to better performance.

However, without additional context or knowledge of the specific requirements or constraints of the benchmark, it's difficult to suggest alternative approaches with confidence.

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser/OS: Chrome 128 on Windows

View result in a separate tab

Test name	Executions per second
acos	1.7 Ops/sec
atan2	4.4 Ops/sec

Related benchmarks:

atan2 vs acos (version: 0)

Comparing performance of: acos vs atan2

Created: 3 years ago by: Guest

Jump to the latest result

acos

atan2

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):