simple-squiggle

A restricted subset of Squiggle
Log | Files | Refs | README

import.js (2547B)

      1 /**
      2  * Math.js can easily be extended with functions and variables using the
      3  * `import` function. The function `import` accepts a module name or an object
      4  * containing functions and variables.
      5  */
      6 
      7 // load math.js (using node.js)
      8 const { create, all } = require('..')
      9 const math = create(all)
     10 
     11 /**
     12  * Define new functions and variables
     13  */
     14 math.import({
     15   myConstant: 42,
     16   hello: function (name) {
     17     return 'hello, ' + name + '!'
     18   }
     19 })
     20 
     21 // defined methods can be used in both JavaScript as well as the parser
     22 print(math.myConstant * 2) // 84
     23 print(math.hello('user')) // 'hello, user!'
     24 
     25 print(math.evaluate('myConstant + 10')) // 52
     26 print(math.evaluate('hello("user")')) // 'hello, user!'
     27 
     28 /**
     29  * Import the math library numbers.js, https://github.com/sjkaliski/numbers.js
     30  * The library must be installed first using npm:
     31  *     npm install numbers
     32  */
     33 try {
     34   // load the numbers.js library
     35   const numbers = require('numbers')
     36 
     37   // import the numbers.js library into math.js
     38   math.import(numbers, { wrap: true, silent: true })
     39 
     40   if (math.fibonacci) {
     41     // calculate fibonacci
     42     print(math.fibonacci(7)) // 13
     43     print(math.evaluate('fibonacci(7)')) // 13
     44   }
     45 } catch (err) {
     46   console.log('Warning: To use numbers.js, the library must ' +
     47       'be installed first via `npm install numbers`.')
     48 }
     49 
     50 /**
     51  * Import the math library numeric.js, https://github.com/sloisel/numeric
     52  * The library must be installed first using npm:
     53  *     npm install numeric
     54  */
     55 try {
     56   // load the numeric.js library
     57   const numeric = require('numeric')
     58 
     59   // import the numeric.js library into math.js
     60   math.import(numeric, { wrap: true, silent: true })
     61 
     62   if (math.eig) {
     63     // calculate eigenvalues of a matrix
     64     print(math.evaluate('eig([1, 2; 4, 3])').lambda.x) // [5, -1]
     65 
     66     // solve AX = b
     67     const A = math.evaluate('[1, 2, 3; 2, -1, 1; 3, 0, -1]')
     68     const b = [9, 8, 3]
     69     print(math.solve(A, b)) // [2, -1, 3]
     70   }
     71 } catch (err) {
     72   console.log('Warning: To use numeric.js, the library must ' +
     73       'be installed first via `npm install numeric`.')
     74 }
     75 
     76 /**
     77  * By default, the function import does not allow overriding existing functions.
     78  * Existing functions can be overridden by specifying option `override: true`
     79  */
     80 math.import({
     81   pi: 3.14
     82 }, {
     83   override: true
     84 })
     85 
     86 print(math.pi) // returns 3.14 instead of 3.141592653589793
     87 
     88 /**
     89  * Helper function to output a value in the console. Value will be formatted.
     90  * @param {*} value
     91  */
     92 function print (value) {
     93   const precision = 14
     94   console.log(math.format(value, precision))
     95 }