• Installing

  NPM

  $npm install las-js

  Yarn

  $yarn add las-js

  Browser

  <script defer src="https://cdn.jsdelivr.net/npm/las-js/dist/browser.js"></srcipt>

• Usage

  import/require las-js module

  Node

  // common js
  const { Las } = require('las-js');
  // esm
  import { Las } from 'las-js';
  const myLas = new Las(`./sample/example1.las`);

  You can also pass LAS file contents directly to constructor

  // common js
  const { Las } = require('las-js');
  const fs = require('fs');
  const data = fs.readFileSync(`./sample/example1.las`, { encoding: 'utf8' });
  // add loadFile: false to constructor options
  const myLas = new Las(data, { loadFile: false });

Browser

las-js adds a global class Lasjs

const input = document.getElementById('file-input');
input.addEventListener('change', async e => {
  const file = e.target.files[0];
  const myLas = new Lasjs(file);
});
// or
const myLas = new Lasjs('https://raw.githubusercontent.com/iykekings/las-js/master/src/__test__/sample/A10.las'); // url - only on browser

• Read data

  Use Laspy.data to get a 2-dimensional array containing the readings of each log, Or Lasjs.dataStripped to get the same as above but with all rows containing null values stripped off

  async function read() {
    try {
      const data = await myLas.data();
      console.log(data);
      /**
         [[2650.0, 177.825, -999.25, -999.25],
          [2650.5, 182.5, -999.25,-999.25],
          [2651.0,180.162, -999.25, -999.25],
          [2651.5, 177.825, -999.25, -999.25],
          [2652.0, 177.825, -999.25, -999.25] ...]
        */
  
      const dataStripped = await myLas.dataStripped();
      console.log(dataStripped);
      /**
       [[2657.5, 212.002, 0.16665, 1951.74597],
       [2658.0, 201.44, 0.1966, 1788.50696],
       [2658.5, 204.314, 0.21004, 1723.21204],
       [2659.0, 212.075, 0.22888, 1638.328],
       [2659.5, 243.536, 0.22439, 1657.91699]...]
       */
    } catch (error) {
      console.log(error);
    }
  }

• Get the log headers

      // ...
      const headers = await myLas.header();
      console.log(headers);
      // ['DEPTH', 'GR', 'NPHI', 'RHOB']
     // ...

• Get the log headers descriptions

      //...
      const headerAndDescr = await myLas.headerAndDescr();
      console.log(headerAndDescr)
      // {DEPTH: 'DEPTH', GR: 'Gamma Ray', NPHI: 'Neutron Porosity', RHOB: 'Bulk density'}
      // ...

• Get a particular column, say Gamma Ray log

      // ...
      const gammaRay = await myLas.column('GR');
      console.log(gammaRay);
      // [-999.25, -999.25, -999.25, -999.25, -999.25, 122.03, 123.14, ...]
      // ...

      // ...
      // get column with null values stripped
      const gammaRay = await myLas.columnStripped('GR');
      console.log(gammaRay);
      // [61.61, 59.99, 54.02, 50.87, 54.68, 64.39, 77.96, ...]
      // ...

  Note this returns the column, after all the data has been stripped off their null values, which means that valid data in a particular column would be stripped off if there is another column that has a null value at that particular row

• Get the Well Parameters

  Presents a way of accessing the details of individual well parameters.

  The details include the following:

    1. descr - Description/ Full name of the well parameter
    2. units - Its unit measurements
    3. value - Value
  

    // ...
    const well = await myLas.wellParams()
    const start = well.STRT.value // 1670.0
    const stop = well.STOP.value // 1669.75
    const null_value = well.NULL.value //  -999.25
    // Any other well parameter present in the file, can be gotten with the same syntax above
    // ...

• Get the Curve Parameters

  Presents a way of accessing the details of individual log columns.

  The details include the following:

    1. descr - Description/ Full name of the log column
    2. units - Unit of the log column measurements
    3. value - API value of the log column
  

    // ...
    const curve = await myLas.curveParams()
    const NPHI = curve.NPHI.descr // 'Neutron Porosity'
    const RHOB = curve.RHOB.descr // 'Bulk density'
    // This is the same for all log column present in the file
    // ...

• Get the Parameters of the well

  The details include the following:

    1. descr - Description/ Full name of the log column
    2. units - Unit of the log column measurements
    3. value - API value of the log column
  

    // ...
    const param = await myLas.logParams(); // 'BOTTOM HOLE TEMPERATURE'
    const BHT = param.BHT.descr // 'BOTTOM HOLE TEMPERATURE'
    const BHTValaue = param.BHT.value // 35.5
    const BHTUnits = param.BHT.units // 'DEGC'
    // This is the same for all well parameters present in the file
    // ...

• Get the number of rows and columns

      // ...
      const numRows = await myLas.rowCount() // 4
      const numColumns = await myLas.columnCount() // 3081
      // ...

• Get the version and wrap

      // ...
      const version = await myLas.version() // '2.0'
      const wrap = await myLas.wrap() // true
      // ...

• Get other information

      // ...
      const other = await myLas.other()
      console.log(other)
      // Note: The logging tools became stuck at 625 metres causing the data between 625 metres and 615 metres to be invalid.
      // ...

• Export to CSV

  For node, this writes a csv file to the current working directory, with headers of the well and data section only for node. For browser, this returns a File Blob, that can be downloaded by using URL.createObjectURL

      //...
      await myLas.toCsv('result')
      // result.csv has been created Successfully!
      //...

  result.csv

  DEPT	RHOB	GR	NPHI
  0.5	-999.25	-999.25	-0.08
  1.0	-999.25	-999.25	-0.08
  1.5	-999.25	-999.25	-0.04
  ...	...	...	...
  1.3	-999.25	-999.25	-0.08

  Or get the version of csv with null values stripped

      // ...
      await myLas.toCsvStripped('clean')
      // clean.csv has been created Successfully!
      // ...

  clean.csv

  DEPT	RHOB	GR	NPHI
  80.5	2.771	18.6	-6.08
  81.0	2.761	17.4	-6.0
  81.5	2.752	16.4	-5.96
  ...	...	...	...
  80.5	2.762	16.2	-5.06

• Browser and Node Supports

  las-js is written in typescript and compiles to es6.

  • Browser Supports IE 10 and 11 - (doesn't yet support url) Doesn't support Opera Mini
  • Node Tested 0n 8, 10 and 12

• Support

  las-js is an MIT-licensed open source project. You can help it grow by becoming a sponsor/supporter.Become a Patron!