mirror of
https://github.com/gosticks/DefinitelyTyped.git
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643 lines
21 KiB
TypeScript
643 lines
21 KiB
TypeScript
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/*
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Basic usage examples
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*/
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(function(){
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// functions and constants
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math.round(math.e, 3); // 2.718
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math.atan2(3, -3) / math.pi; // 0.75
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math.log(10000, 10); // 4
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math.sqrt(-4); // 2i
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math.pow([[-1, 2], [3, 1]], 2); // [[7, 0], [0, 7]]
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var angle = 0.2;
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math.add(math.pow(math.sin(angle), 2), math.pow(math.cos(angle), 2)); // returns number ~1
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// expressions
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math.eval('1.2 * (2 + 4.5)'); // 7.8
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math.eval('5.08 cm to inch'); // 2 inch
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math.eval('sin(45 deg) ^ 2'); // 0.5
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math.eval('9 / 3 + 2i'); // 3 + 2i
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math.eval('det([-1, 2; 3, 1])'); // -7
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// chained operations
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var a = math.chain(3)
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.add(4)
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.multiply(2)
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.done(); // 14
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// mixed use of different data types in functions
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console.log('mixed use of data types');
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math.add(4, [5, 6]); // number + Array, [9, 10]
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math.multiply(math.unit('5 mm'), 3); // Unit * number, 15 mm
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math.subtract([2, 3, 4], 5); // Array - number, [-3, -2, -1]
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math.add(math.matrix([2, 3]), [4, 5]); // Matrix + Array, [6, 8]
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}());
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/*
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Bignumbers examples
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*/
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(function() {
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// configure the default type of numbers as BigNumbers
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math.config({
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number: 'bignumber', // Default type of number:
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// 'number' (default), 'bignumber', or 'fraction'
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precision: 20 // Number of significant digits for BigNumbers
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});
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console.log('round-off errors with numbers');
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math.add(0.1, 0.2); // number, 0.30000000000000004
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math.divide(0.3, 0.2); // number, 1.4999999999999998
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console.log();
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console.log('no round-off errors with BigNumbers');
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math.add(math.bignumber(0.1), math.bignumber(0.2)); // BigNumber, 0.3
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math.divide(math.bignumber(0.3), math.bignumber(0.2)); // BigNumber, 1.5
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console.log();
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console.log('create BigNumbers from strings when exceeding the range of a number');
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math.bignumber(1.2e+500); // BigNumber, Infinity WRONG
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math.bignumber('1.2e+500'); // BigNumber, 1.2e+500
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console.log();
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// one can work conveniently with BigNumbers using the expression parser.
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// note though that BigNumbers are only supported in arithmetic functions
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console.log('use BigNumbers in the expression parser');
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math.eval('0.1 + 0.2'); // BigNumber, 0.3
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math.eval('0.3 / 0.2'); // BigNumber, 1.5
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console.log();
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}());
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/*
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Chaining examples
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*/
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(function() {
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// create a chained operation using the function `chain(value)`
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// end a chain using done(). Let's calculate (3 + 4) * 2
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var a = math.chain(3)
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.add(4)
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.multiply(2)
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.done(); // 14
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// Another example, calculate square(sin(pi / 4))
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var b = math.chain(math.pi)
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.divide(4)
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.sin()
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.square()
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.done(); // 0.5
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// A chain has a few special methods: done, toString, valueOf, get, and set.
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// these are demonstrated in the following examples
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// toString will return a string representation of the chain's value
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var chain = math.chain(2).divide(3);
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var str = chain.toString(); // "0.6666666666666666"
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// a chain has a function .valueOf(), which returns the value hold by the chain.
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// This allows using it in regular operations. The function valueOf() acts the
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// same as function done().
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chain.valueOf(); // 0.66666666666667
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// the function subset can be used to get or replace sub matrices
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var array = [[1, 2], [3, 4]];
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var v = math.chain(array)
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.subset(math.index(1, 0))
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.done(); // 3
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var m = math.chain(array)
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.subset(math.index(0, 0), 8)
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.multiply(3)
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.done(); // [[24, 6], [9, 12]]
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}());
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/*
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Complex numbers examples
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*/
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(function(){
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var a = math.complex(2, 3); // 2 + 3i
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// read the real and complex parts of the complex number
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a.re; // 2
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a.im; // 3
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// clone a complex value
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var clone = a.clone(); // 2 + 3i
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// adjust the complex value
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a.re = 5; // 5 + 3i
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// create a complex number by providing a string with real and complex parts
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var b = math.complex('3 - 7i'); // 3 - 7i
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console.log();
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// perform operations with complex numbers
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console.log('perform operations');
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math.add(a, b); // 8 - 4i
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math.multiply(a, b); // 36 - 26i
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math.sin(a); // -9.6541254768548 + 2.8416922956064i
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// some operations will return a complex number depending on the arguments
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math.sqrt(4); // 2
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math.sqrt(-4); // 2i
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// create a complex number from polar coordinates
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console.log('create complex numbers with polar coordinates');
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var c = math.complex({r: math.sqrt(2), phi: math.pi / 4}); // 1 + i
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// get polar coordinates of a complex number
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var d = math.complex(3, 4);
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d.toPolar(); // { r: 5, phi: 0.9272952180016122 }
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}());
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/*
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Expressions examples
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*/
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(function() {
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// 1. using the function math.eval
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//
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// Function `eval` accepts a single expression or an array with
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// expressions as first argument, and has an optional second argument
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// containing a scope with variables and functions. The scope is a regular
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// JavaScript Object. The scope will be used to resolve symbols, and to write
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// assigned variables or function.
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console.log('1. USING FUNCTION MATH.EVAL');
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// evaluate expressions
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console.log('\nevaluate expressions');
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math.eval('sqrt(3^2 + 4^2)'); // 5
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math.eval('sqrt(-4)'); // 2i
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math.eval('2 inch to cm'); // 5.08 cm
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math.eval('cos(45 deg)'); // 0.70711
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// evaluate multiple expressions at once
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console.log('\nevaluate multiple expressions at once');
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math.eval([
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'f = 3',
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'g = 4',
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'f * g'
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]); // [3, 4, 12]
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// provide a scope (just a regular JavaScript Object)
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console.log('\nevaluate expressions providing a scope with variables and functions');
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var scope: any = {
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a: 3,
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b: 4
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};
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// variables can be read from the scope
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math.eval('a * b', scope); // 12
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// variable assignments are written to the scope
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math.eval('c = 2.3 + 4.5', scope); // 6.8
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scope.c; // 6.8
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// scope can contain both variables and functions
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scope["hello"] = function (name: string) {
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return 'hello, ' + name + '!';
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};
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math.eval('hello("hero")', scope); // "hello, hero!"
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// define a function as an expression
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var f = math.eval('f(x) = x ^ a', scope);
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f(2); // 8
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scope.f(2); // 8
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// 2. using function math.parse
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//
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// Function `math.parse` parses expressions into a node tree. The syntax is
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// similar to function `math.eval`.
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// Function `parse` accepts a single expression or an array with
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// expressions as first argument. The function returns a node tree, which
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// then can be compiled against math, and then evaluated against an (optional
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// scope. This scope is a regular JavaScript Object. The scope will be used
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// to resolve symbols, and to write assigned variables or function.
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console.log('\n2. USING FUNCTION MATH.PARSE');
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// parse an expression
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console.log('\nparse an expression into a node tree');
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var node1 = math.parse('sqrt(3^2 + 4^2)');
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node1.toString(); // "sqrt((3 ^ 2) + (4 ^ 2))"
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// compile and evaluate the compiled code
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// you could also do this in two steps: node1.compile().eval()
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node1.eval(); // 5
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// provide a scope
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console.log('\nprovide a scope');
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var node2 = math.parse('x^a');
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var code2 = node2.compile();
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node2.toString(); // "x ^ a"
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var scope: any = {
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x: 3,
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a: 2
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};
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code2.eval(scope); // 9
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// change a value in the scope and re-evaluate the node
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scope.a = 3;
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code2.eval(scope); // 27
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// 3. using function math.compile
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//
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// Function `math.compile` compiles expressions into a node tree. The syntax is
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// similar to function `math.eval`.
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// Function `compile` accepts a single expression or an array with
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// expressions as first argument, and returns an object with a function eval
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// to evaluate the compiled expression. On evaluation, an optional scope can
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// be provided. This scope will be used to resolve symbols, and to write
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// assigned variables or function.
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console.log('\n3. USING FUNCTION MATH.COMPILE');
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// parse an expression
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console.log('\ncompile an expression');
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var code3 = math.compile('sqrt(3^2 + 4^2)');
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// evaluate the compiled code
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code3.eval(); // 5
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// provide a scope for the variable assignment
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console.log('\nprovide a scope');
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var code2 = math.compile('a = a + 3');
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var scope: any = {
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a: 7
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};
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code2.eval(scope);
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scope.a; // 10
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// 4. using a parser
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//
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// In addition to the static functions `math.eval` and `math.parse`, math.js
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// contains a parser with functions `eval` and `parse`, which automatically
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// keeps a scope with assigned variables in memory. The parser also contains
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// some convenience methods to get, set, and remove variables from memory.
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console.log('\n4. USING A PARSER');
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var parser = math.parser();
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// evaluate with parser
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console.log('\nevaluate expressions');
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parser.eval('sqrt(3^2 + 4^2)'); // 5
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parser.eval('sqrt(-4)'); // 2i
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parser.eval('2 inch to cm'); // 5.08 cm
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parser.eval('cos(45 deg)'); // 0.70711
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// define variables and functions
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console.log('\ndefine variables and functions');
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parser.eval('x = 7 / 2'); // 3.5
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parser.eval('x + 3'); // 6.5
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parser.eval('f(x, y) = x^y'); // f(x, y)
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parser.eval('f(2, 3)'); // 8
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// manipulate matrices
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// Note that matrix indexes in the expression parser are one-based with the
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// upper-bound included. On a JavaScript level however, math.js uses zero-based
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// indexes with an excluded upper-bound.
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console.log('\nmanipulate matrices');
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parser.eval('k = [1, 2; 3, 4]'); // [[1, 2], [3, 4]]
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parser.eval('l = zeros(2, 2)'); // [[0, 0], [0, 0]]
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parser.eval('l[1, 1:2] = [5, 6]'); // [[5, 6], [0, 0]]
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parser.eval('l[2, :] = [7, 8]'); // [[5, 6], [7, 8]]
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parser.eval('m = k * l'); // [[19, 22], [43, 50]]
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parser.eval('n = m[2, 1]'); // 43
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parser.eval('n = m[:, 1]'); // [[19], [43]]
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// get and set variables and functions
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console.log('\nget and set variables and function in the scope of the parser');
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var x = parser.get('x');
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console.log('x =', x); // x = 7
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var f = parser.get('f');
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console.log('f =', math.format(f)); // f = f(x, y)
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var g = f(3, 3);
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console.log('g =', g); // g = 27
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parser.set('h', 500);
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parser.eval('h / 2'); // 250
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parser.set('hello', function (name: string) {
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return 'hello, ' + name + '!';
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});
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parser.eval('hello("hero")'); // "hello, hero!"
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// clear defined functions and variables
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parser.clear();
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}());
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/*
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Fractions examples
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*/
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(function(){
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// configure the default type of numbers as Fractions
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math.config({
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number: 'fraction' // Default type of number:
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// 'number' (default), 'bignumber', or 'fraction'
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});
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console.log('basic usage');
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math.fraction(0.125); // Fraction, 1/8
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math.fraction(0.32); // Fraction, 8/25
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math.fraction('1/3'); // Fraction, 1/3
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math.fraction('0.(3)'); // Fraction, 1/3
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math.fraction(2, 3); // Fraction, 2/3
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math.fraction('0.(285714)'); // Fraction, 2/7
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console.log();
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console.log('round-off errors with numbers');
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math.add(0.1, 0.2); // number, 0.30000000000000004
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math.divide(0.3, 0.2); // number, 1.4999999999999998
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console.log();
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console.log('no round-off errors with fractions :)');
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math.add(math.fraction(0.1), math.fraction(0.2)); // Fraction, 3/10
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math.divide(math.fraction(0.3), math.fraction(0.2)); // Fraction, 3/2
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console.log();
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console.log('represent an infinite number of repeating digits');
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math.fraction('1/3'); // Fraction, 0.(3)
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math.fraction('2/7'); // Fraction, 0.(285714)
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math.fraction('23/11'); // Fraction, 2.(09)
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console.log();
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// one can work conveniently with fractions using the expression parser.
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// note though that Fractions are only supported by basic arithmetic functions
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console.log('use fractions in the expression parser');
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math.eval('0.1 + 0.2'); // Fraction, 3/10
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math.eval('0.3 / 0.2'); // Fraction, 3/2
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math.eval('23 / 11'); // Fraction, 23/11
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console.log();
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// output formatting
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console.log('output formatting of fractions');
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var a = math.fraction('2/3');
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console.log(math.format(a)); // Fraction, 2/3
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console.log(math.format(a, {fraction: 'ratio'})); // Fraction, 2/3
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console.log(math.format(a, {fraction: 'decimal'})); // Fraction, 0.(6)
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console.log(a.toString()); // Fraction, 0.(6)
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console.log();
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}());
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/*
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Matrices examples
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*/
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(function() {
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// create matrices and arrays. a matrix is just a wrapper around an Array,
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// providing some handy utilities.
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console.log('create a matrix');
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var a = math.matrix([1, 4, 9, 16, 25]); // [1, 4, 9, 16, 25]
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var b = math.matrix(math.ones([2, 3])); // [[1, 1, 1], [1, 1, 1]]
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b.size(); // [2, 3]
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// the Array data of a Matrix can be retrieved using valueOf()
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var array = a.valueOf(); // [1, 4, 9, 16, 25]
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// Matrices can be cloned
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var clone = a.clone(); // [1, 4, 9, 16, 25]
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console.log();
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// perform operations with matrices
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console.log('perform operations');
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math.sqrt(a); // [1, 2, 3, 4, 5]
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var c = [1, 2, 3, 4, 5];
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math.factorial(c); // [1, 2, 6, 24, 120]
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console.log();
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// create and manipulate matrices. Arrays and Matrices can be used mixed.
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console.log('manipulate matrices');
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var d = [[1, 2], [3, 4]]; // [[1, 2], [3, 4]]
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var e = math.matrix([[5, 6], [1, 1]]); // [[5, 6], [1, 1]]
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// set a submatrix.
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// Matrix indexes are zero-based.
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e.subset(math.index(1, [0, 1]), [[7, 8]]); // [[5, 6], [7, 8]]
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var f = math.multiply(d, e); // [[19, 22], [43, 50]]
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var g = f.subset(math.index(1, 0)); // 43
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console.log();
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// get a sub matrix
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// Matrix indexes are zero-based.
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console.log('get a sub matrix');
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var h = math.diag(math.range(1,4)); // [[1, 0, 0], [0, 2, 0], [0, 0, 3]]
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h.subset( math.index([1, 2], [1, 2])); // [[2, 0], [0, 3]]
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var i = math.range(1,6); // [1, 2, 3, 4, 5]
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i.subset(math.index(math.range(1,4))); // [2, 3, 4]
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console.log();
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// resize a multi dimensional matrix
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console.log('resizing a matrix');
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var j = math.matrix();
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var defaultValue = 0;
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j.resize([2, 2, 2], defaultValue); // [[[0, 0], [0, 0]], [[0, 0], [0, 0]]]
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j.size(); // [2, 2, 2]
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j.resize([2, 2]); // [[0, 0], [0, 0]]
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j.size(); // [2, 2]
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console.log();
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// setting a value outside the matrices range will resize the matrix.
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// new elements will be initialized with zero.
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console.log('set a value outside a matrices range');
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var k = math.matrix();
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k.subset(math.index(2), 6); // [0, 0, 6]
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console.log();
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console.log('set a value outside a matrices range, leaving new entries uninitialized');
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var m = math.matrix();
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defaultValue = math.uninitialized;
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m.subset(math.index(2), 6, defaultValue); // [undefined, undefined, 6]
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console.log();
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// create ranges
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console.log('create ranges');
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math.range(1, 6); // [1, 2, 3, 4, 5]
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math.range(0, 18, 3); // [0, 3, 6, 9, 12, 15]
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math.range('2:-1:-3'); // [2, 1, 0, -1, -2]
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math.factorial(math.range('1:6')); // [1, 2, 6, 24, 120]
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console.log();
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}());
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/*
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Sparse matrices examples
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*/
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(function() {
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// create a sparse matrix
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console.log('creating a 1000x1000 sparse matrix...');
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var a = math.eye(1000, 1000, 'sparse');
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// do operations with a sparse matrix
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console.log('doing some operations on the sparse matrix...');
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var b = math.multiply(a, a);
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var c = math.multiply(b, math.complex(2, 2));
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var d = math.transpose(c);
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|
var e = math.multiply(d, a);
|
|
|
|
// we will not print the output, but doing the same operations
|
|
// with a dense matrix are very slow, try it for yourself.
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|
console.log('already done');
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|
console.log('now try this with a dense matrix :)');
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|
}());
|
|
|
|
/*
|
|
Units examples
|
|
*/
|
|
(function() {
|
|
// units can be created by providing a value and unit name, or by providing
|
|
// a string with a valued unit.
|
|
console.log('create units');
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|
var a = math.unit(45, 'cm'); // 450 mm
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|
var b = math.unit('0.1m'); // 100 mm
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|
console.log();
|
|
|
|
// units can be added, subtracted, and multiplied or divided by numbers and by other units
|
|
console.log('perform operations');
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|
math.add(a, b); // 0.55 m
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|
math.multiply(b, 2); // 200 mm
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|
math.divide(math.unit('1 m'), math.unit('1 s')); // 1 m / s
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|
math.pow(math.unit('12 in'), 3); // 1728 in^3
|
|
console.log();
|
|
|
|
// units can be converted to a specific type, or to a number
|
|
console.log('convert to another type or to a number');
|
|
b.to('cm'); // 10 cm Alternatively: math.to(b, 'cm')
|
|
math.to(b, 'inch'); // 3.9370... inch
|
|
b.toNumber('cm'); // 10
|
|
math.number(b, 'cm'); // 10
|
|
console.log();
|
|
|
|
// the expression parser supports units too
|
|
console.log('parse expressions');
|
|
math.eval('2 inch to cm'); // 5.08 cm
|
|
math.eval('cos(45 deg)'); // 0.70711...
|
|
math.eval('90 km/h to m/s'); // 25 m / s
|
|
console.log();
|
|
|
|
// convert a unit to a number
|
|
// A second parameter with the unit for the exported number must be provided
|
|
math.eval('number(5 cm, mm)'); // number, 50
|
|
console.log();
|
|
|
|
// simplify units
|
|
console.log('simplify units');
|
|
math.eval('100000 N / m^2'); // 100 kPa
|
|
math.eval('9.81 m/s^2 * 100 kg * 40 m'); // 39.24 kJ
|
|
console.log();
|
|
|
|
// example engineering calculations
|
|
console.log('compute molar volume of ideal gas at 65 Fahrenheit, 14.7 psi in L/mol');
|
|
var Rg = math.unit('8.314 N m / (mol K)');
|
|
var T = math.unit('65 degF');
|
|
var P = math.unit('14.7 psi');
|
|
var v = math.divide(math.multiply(Rg, T), P);
|
|
console.log('gas constant (Rg) = ', format(Rg));
|
|
console.log('P = ' + format(P));
|
|
console.log('T = ' + format(T));
|
|
console.log('v = Rg * T / P = ' + format(math.to(v, 'L/mol'))); // 23.910... L / mol
|
|
console.log();
|
|
|
|
console.log('compute speed of fluid flowing out of hole in a container');
|
|
var g = math.unit('9.81 m / s^2');
|
|
var h = math.unit('1 m');
|
|
var v2 = math.pow(math.multiply(2, math.multiply(g, h)), 0.5); // Can also use math.sqrt
|
|
console.log('g = ' + format(g));
|
|
console.log('h = ' + format(h));
|
|
console.log('v = (2 g h) ^ 0.5 = ' + format(v2)); // 4.429... m / s
|
|
console.log();
|
|
|
|
console.log('electrical power consumption:');
|
|
var expr = '460 V * 20 A * 30 days to kWh';
|
|
console.log(expr + ' = ' + math.eval(expr)); // 6624 kWh
|
|
console.log();
|
|
|
|
console.log('circuit design:');
|
|
var expr = '24 V / (6 mA)';
|
|
console.log(expr + ' = ' + math.eval(expr)); // 4 kohm
|
|
console.log();
|
|
|
|
console.log('operations on arrays:');
|
|
var B = math.eval('[1, 0, 0] T');
|
|
var v3 = math.eval('[0, 1, 0] m/s');
|
|
var q = math.eval('1 C');
|
|
var F = math.multiply(q, math.cross(v3, B));
|
|
console.log('B (magnetic field strength) = ' + format(B)); // [1 T, 0 T, 0 T]
|
|
console.log('v (particle velocity) = ' + format(v3)); // [0 m / s, 1 m / s, 0 m / s]
|
|
console.log('q (particle charge) = ' + format(q)); // 1 C
|
|
console.log('F (force) = q (v cross B) = ' + format(F)); // [0 N, 0 N, -1 N]
|
|
|
|
/**
|
|
* Helper function to format an output a value.
|
|
* @param {*} value
|
|
* @return {string} Returns the formatted value
|
|
*/
|
|
function format (value: any): string {
|
|
var precision = 14;
|
|
return math.format(value, precision);
|
|
}
|
|
}());
|
|
|
|
|
|
/*
|
|
Expression tree examples
|
|
*/
|
|
(function(){
|
|
|
|
// Filter an expression tree
|
|
console.log('Filter all symbol nodes "x" in the expression "x^2 + x/4 + 3*y"');
|
|
var node = math.parse('x^2 + x/4 + 3*y');
|
|
var filtered = node.filter(function (node) {
|
|
return node.isSymbolNode && node.name == 'x';
|
|
});
|
|
// returns an array with two entries: two SymbolNodes 'x'
|
|
|
|
filtered.forEach(function (node) {
|
|
console.log(node.type, node.toString())
|
|
});
|
|
// outputs:
|
|
// SymbolNode x
|
|
// SymbolNode x
|
|
|
|
|
|
// Traverse an expression tree
|
|
console.log();
|
|
console.log('Traverse the expression tree of expression "3 * x + 2"');
|
|
var node1 = math.parse('3 * x + 2');
|
|
node1.traverse(function (node, path, parent) {
|
|
switch (node.type) {
|
|
// case 'OperatorNode': console.log(node.type, node.op); break;
|
|
case 'OperatorNode': console.log(node.type); break;//for now removing .op
|
|
case 'ConstantNode': console.log(node.type, node.value); break;
|
|
case 'SymbolNode': console.log(node.type, node.name); break;
|
|
default: console.log(node.type);
|
|
}
|
|
});
|
|
// outputs:
|
|
// OperatorNode +
|
|
// OperatorNode *
|
|
// ConstantNode 3
|
|
// SymbolNode x
|
|
// ConstantNode 2
|
|
|
|
|
|
// transform an expression tree
|
|
// console.log();
|
|
// console.log('Replace all symbol nodes "x" in expression "x^2 + 5*x" with a constant 3');
|
|
// var node2 = math.parse('x^2 + 5*x');
|
|
// var transformed = node2.transform(function (node, path, parent) {
|
|
// if (node.isSymbolNode && node.name == 'x') {
|
|
// return new math.expression.node.ConstantNode(3);
|
|
// }
|
|
// else {
|
|
// return node;
|
|
// }
|
|
// });
|
|
// console.log(transformed.toString());
|
|
// outputs: '(3 ^ 2) + (5 * 3)'
|
|
}());
|