Benchmark: trunc-benchmark - MeasureThat.net

Script Preparation code:

function dosDecimales(n) {
  let t=n.toString();
  let regex=/(\d*.\d{0,2})/;
  return t.match(regex)[0];
}

function trunc (x, posiciones = 0) {
  var s = x.toString()
  var l = s.length
  var decimalLength = s.indexOf('.') + 1

  if (l - decimalLength <= posiciones){
    return x
  }
  // Parte decimal del número
  var isNeg  = x < 0
  var decimal =  x % 1
  var entera  = isNeg ? Math.ceil(x) : Math.floor(x)
  // Parte decimal como número entero
  // Ejemplo: parte decimal = 0.77
  // decimalFormated = 0.77 * (10^posiciones)
  // si posiciones es 2 ==> 0.77 * 100
  // si posiciones es 3 ==> 0.77 * 1000
  var decimalFormated = Math.floor(
    Math.abs(decimal) * Math.pow(10, posiciones)
  )
  // Sustraemos del número original la parte decimal
  // y le sumamos la parte decimal que hemos formateado
  var finalNum = entera + 
    ((decimalFormated / Math.pow(10, posiciones))*(isNeg ? -1 : 1))
  
  return finalNum
}

function trunc2 (x, posiciones = 0) {
  var s = x.toString()
  var l = s.length
  var decimalLength = s.indexOf('.') + 1
  var numStr = s.substr(0, decimalLength + posiciones)
  return Number(numStr)
}

function trunc_fixed (x, posiciones = 0) {
  return +x.toFixed(posiciones);
}

Tests:

Trunc Mat
trunc(17.97777, 2)
Trunc
trunc2(17.97777, 2)
dosDecimales
dosDecimales(17.97777, 2)
trunc_fixed
trunc_fixed(17.97777, 2)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Trunc Mat
Trunc
dosDecimales
trunc_fixed

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided JSON data and explain what is being tested, compared, and their pros and cons.

**Benchmark Definition**

The `trunc-benchmark` benchmark tests four different functions that perform decimal truncation (rounding down to a specified number of decimal places) on a given number:

1. `trunc(x, posiciones = 0)`: This function takes an optional second argument `posiciones` which specifies the maximum number of decimal places to keep.
2. `trunc2(x, posiciones = 0)`: Similar to `trunc`, but uses `substr()` to extract a substring from the original string representation of `x`.
3. `dosDecimales(n, posiciones = 0)`: This function takes an optional second argument `posiciones` which specifies the maximum number of decimal places to keep.
4. `trunc_fixed(x, posiciones = 0)`: This function uses the `toFixed()` method to round down `x` to a specified number of decimal places.

**Comparison**

The four functions are compared in terms of performance (measured as "ExecutionsPerSecond") using different JavaScript engines and platforms.

**Pros and Cons**

Here's a brief overview of each approach:

1. `trunc(x, posiciones = 0)`: This implementation uses arithmetic operations to calculate the decimal part and then applies rounding logic. Pros: simple and efficient for small numbers. Cons: may not perform well for very large or very small numbers due to potential integer overflow.
2. `trunc2(x, posiciones = 0)`: Using `substr()` can be slower than arithmetic-based implementations, but it's often more reliable for handling strings with decimal points. Pros: handles string manipulation correctly, Cons: may be slower.
3. `dosDecimales(n, posiciones = 0)`: This implementation uses a regular expression to extract the decimal part from the string representation of `n`. Pros: simple and efficient for small numbers. Cons: may not perform well for very large or very small numbers due to potential regex performance issues.
4. `trunc_fixed(x, posiciones = 0)`: Using `toFixed()` can be slower than arithmetic-based implementations, but it's often more reliable for handling decimal points. Pros: handles decimal point correctly, Cons: may be slower.

**Libraries and Features**

* No external libraries are used in these benchmark functions.
* No special JavaScript features or syntax are used beyond basic arithmetic operations and string manipulation.

**Alternative Approaches**

Other approaches to performing decimal truncation might include:

1. Using a dedicated decimal arithmetic library (e.g., `decimal.js`).
2. Implementing decimal truncation using bitwise operations (e.g., shifting and masking).
3. Using a Just-In-Time (JIT) compiler or other optimization techniques to improve performance.

These alternatives may offer better performance, reliability, or readability, depending on the specific use case and requirements.

Latest run results:

Run details: (Test run date: 7 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36

Browser/OS: Chrome 61 on Windows

View result in a separate tab

Test name	Executions per second
Trunc Mat	1126176.8 Ops/sec
Trunc	2990419.8 Ops/sec
dosDecimales	4521223.5 Ops/sec
trunc_fixed	2468306.5 Ops/sec

Related benchmarks:

trunc-benchmark (version: 0)

trunc

Comparing performance of: Trunc Mat vs Trunc vs dosDecimales vs trunc_fixed

Created: 7 years ago by: Guest

Jump to the latest result

Trunc Mat

Trunc

dosDecimales

trunc_fixed

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):