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94 lines
3.3 KiB
JavaScript
94 lines
3.3 KiB
JavaScript
// matrices
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// load math.js
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var math = require('../math.js');
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/**
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* Helper function to output d value in the console. Value will be formatted.
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* @param {*} value
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*/
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function print (value) {
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console.log(math.format(value));
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}
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// create matrices and arrays. d matrix is just d 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]);
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print(a); // [1, 4, 9, 16, 25]
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var b = math.ones([2, 3]);
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print(b); // [[1, 1, 1], [1, 1, 1]]
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print(b.size()); // [2, 3]
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// the Array data of d Matrix can be retrieved using valueOf()
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var array = a.valueOf();
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print(array); // [1, 4, 9, 16, 25]
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// Matrices can be cloned
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var clone = a.clone();
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print(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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print(math.sqrt(a)); // [1, 2, 3, 4, 5]
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var c = [1, 2, 3, 4, 5];
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print(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]];
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print(d); // [[1, 2], [3, 4]]
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var e = math.matrix([[5, 6], [1, 1]]);
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print(e); // [[5, 6], [1, 1]]
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// set d submatrix
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e.set([2, [1, 2]], [[7, 8]]);
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print(e); // [[5, 6], [7, 8]]
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var f = math.multiply(d, e);
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print(f); // [[19, 22], [43, 50]]
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var g = f.get([2, 1]);
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print(g); // 43
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console.log();
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// get d sub matrix
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console.log('get a sub matrix');
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var h = math.diag(math.range(1,3));
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print(h); // [[1, 0, 0], [0, 2, 0], [0, 0, 3]]
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print(h.get([[2, 3], [2, 3]])); // [[2, 0], [0, 3]]
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console.log();
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// resize d multi dimensional matrix
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console.log('resizing a matrix');
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var i = math.matrix();
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i.resize([2, 2, 2]);
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print(i); // [[[0, 0], [0, 0]], [[0, 0], [0, 0]]]
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print(i.size()); // [2, 2, 2]
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i.resize([2, 2]);
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print(i); // [[0, 0], [0, 0]]
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print(i.size()); // [2, 2]
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i.set([3, 2], 6);
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print(i); // [[0, 0], [0, 0], [0, 6]]
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print(i.size()); // [3, 2]
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console.log();
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// create ranges
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console.log('create ranges');
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print(math.range(1,5).toArray()); // [1, 2, 3, 4, 5]
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print(math.range(0, 3, 15).toArray()); // [0, 3, 6, 9, 12, 15]
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print(math.range('2:-1:-2').toArray()); // [2, 1, 0, -1, -2]
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print(math.factorial(math.range('1:5'))); // [1, 2, 6, 24, 120]
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console.log();
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console.log('use the expression parser');
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var parser = math.parser();
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print(parser.eval('d = [1, 2; 3, 4]')); // [[1, 2], [3, 4]]
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print(parser.eval('e = zeros(2, 2)')); // [[0, 0], [0, 0]]
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print(parser.eval('e(1, 1:2) = [5, 6]')); // [[5, 6], [0, 0]]
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print(parser.eval('e(2, :) = [7, 8]')); // [[5, 6], [7, 8]]
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print(parser.eval('f = d * e')); // [[19, 22], [43, 50]]
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print(parser.eval('g = f(2, 1)')); // 43
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print(parser.eval('g = f(:, 1)')); // [[19], [43]]
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console.log();
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