Benchmark: acos vs atan2 - 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]/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 benchmark and its options.

**Benchmark Definition**

The test compares two JavaScript functions: `Math.acos` (acos) and `Math.atan2` (atan2). Both functions are used to calculate the inverse cosine and inverse tangent of a given value, respectively. However, `Math.atan2` also takes into account the quadrant of the angle.

**Options compared**

The test compares two approaches:

1. `Math.acos`: This function uses the arcsine (inverse sine) formula to calculate the angle, which can lead to inaccurate results for certain input values.
2. `Math.atan2`: This function uses a combination of the arctangent (inverse tangent) and quadrant-dependent calculations to ensure accurate results across all quadrants.

**Pros and Cons**

* **`Math.acos`**:
	+ Pros: simpler implementation, faster execution.
	+ Cons: can lead to inaccurate results for certain input values.
* **`Math.atan2`**:
	+ Pros: more accurate results across all quadrants, handles edge cases better.
	+ Cons: slower execution due to the additional calculations.

**Library**

There is no library explicitly mentioned in the benchmark definition. However, `Math` functions are part of the standard JavaScript library, which means they are available on most platforms and browsers.

**Special JS feature or syntax**

None of the test cases use any special JavaScript features or syntax that would require explanation outside of this context.

**Other alternatives**

If you wanted to write a similar benchmark for other inverse trigonometric functions in JavaScript, you could consider testing:

* `Math.asin` (arcsine)
* `Math.atan` (arctangent) with the same quadrant-dependent calculation as `Math.atan2`
* Other libraries or frameworks that provide alternative implementations of these functions.

Keep in mind that writing a benchmark for inverse trigonometric functions can be complex due to the mathematical intricacies involved, so it's essential to carefully consider the test cases and options compared.

Latest run results:

Run details: (Test run date: 6 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:125.0) Gecko/20100101 Firefox/125.0

Browser/OS: Firefox 125 on Windows

View result in a separate tab

Test name	Executions per second
acos	0.0 Ops/sec
atan2	28.1 Ops/sec

Related benchmarks:

acos vs atan2 (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):