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76 lines
2.3 KiB
Markdown
76 lines
2.3 KiB
Markdown
# Import
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The library can easily be extended with functions and variables using the
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`import` function. The function `import` accepts a filename or an object with
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functions and variables.
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Function `import` has the following syntax:
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```js
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math.import(object: Object [, options: Object])
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math.import(moduleName: String [, options: Object])
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```
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The first argument can be a module name or an object. The optional second
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argument can be an object with options. The following options are available:
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- `{Boolean} override`
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If true, existing functions will be overwritten. False by default.
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- `{Boolean} wrap`
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If true (default), the functions will be wrapped in a wrapper function which
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converts data types like Matrix to primitive data types like Array.
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The wrapper is needed when extending math.js with libraries which do not
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support the math.js data types.
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Math.js can be extended with functions and variables:
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```js
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// create an instance of math.js
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var math = require('mathjs')();
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// define new functions and variables
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math.import({
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myvalue: 42,
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hello: function (name) {
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return 'hello, ' + name + '!';
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}
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});
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// defined functions can be used in both JavaScript as well as the parser
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math.myvalue * 2; // 84
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math.hello('user'); // 'hello, user!'
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var parser = math.parser();
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parser.eval('myvalue + 10'); // 52
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parser.eval('hello("user")'); // 'hello, user!'
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```
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External libraries like
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[numbers.js](https://github.com/sjkaliski/numbers.js) and
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[numeric.js](http://numericjs.com/) can be imported as well.
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The libraries must be installed using npm:
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npm install numbers
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npm install numeric
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The libraries can be easily imported into math.js using `import`. By default,
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existing functions will not be overwritten, and math.js will create a wrapper
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function around the imported functions which converts data types like `Matrix`
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to primitive types like `Array`.
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```js
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// create an instance of math.js
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var math = require('mathjs')();
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// import the numbers.js and numeric.js libraries into math.js
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math.import('numbers');
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math.import('numeric');
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// use functions from numbers.js
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math.fibonacci(7); // 13
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math.eval('fibonacci(7)'); // 13
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// use functions from numeric.js
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math.eval('eig([1, 2; 4, 3])').lambda.x; // [5, -1]
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```
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