https://github.com/laslibs/las-js
Typescript/JavaScript library for parsing standard well log files (Geophysical well logs))
https://github.com/laslibs/las-js
csv javascript-library las las-js parsing typescript well-logs
Last synced: 19 days ago
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Typescript/JavaScript library for parsing standard well log files (Geophysical well logs))
- Host: GitHub
- URL: https://github.com/laslibs/las-js
- Owner: laslibs
- License: mit
- Created: 2019-09-02T07:00:50.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2024-07-20T06:44:27.000Z (over 1 year ago)
- Last Synced: 2025-08-09T09:43:42.028Z (7 months ago)
- Topics: csv, javascript-library, las, las-js, parsing, typescript, well-logs
- Language: Lasso
- Homepage: https://www.npmjs.com/package/las-js
- Size: 376 KB
- Stars: 28
- Watchers: 3
- Forks: 10
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
Awesome Lists containing this project
README
# las-js is a zero-dependency JavaScript library for parsing .Las file (Geophysical well log files).
### Currently supports only version 2.0 of [LAS Specification](https://www.cwls.org/wp-content/uploads/2017/02/Las2_Update_Feb2017.pdf). For more information about this format, see the Canadian Well Logging Society [product page](https://www.cwls.org/products/).
## How to use
- Installing
> NPM
```sh
$npm install las-js
```
> Yarn
```sh
$yarn add las-js
```
> Browser
```html
```
- Usage
import/require las-js module
> Node
```js
// 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
```js
// 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
```js
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
```js
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
```javascript
// ...
const headers = await myLas.header();
console.log(headers);
// ['DEPTH', 'GR', 'NPHI', 'RHOB']
// ...
```
- Get the log headers descriptions
```Js
//...
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
```Js
// ...
const gammaRay = await myLas.column('GR');
console.log(gammaRay);
// [-999.25, -999.25, -999.25, -999.25, -999.25, 122.03, 123.14, ...]
// ...
```
```Js
// ...
// 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
```Js
// ...
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
```Js
// ...
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
```Js
// ...
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
```Js
// ...
const numRows = await myLas.rowCount() // 4
const numColumns = await myLas.columnCount() // 3081
// ...
```
- Get the version and wrap
```Js
// ...
const version = await myLas.version() // '2.0'
const wrap = await myLas.wrap() // true
// ...
```
- Get other information
```Js
// ...
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_
```Js
//...
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
```Js
// ...
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!](https://www.patreon.com/bePatron?u=19152008)