Add norm of matrix #57
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targos
reviewed
Jul 18, 2017
src/abstractMatrix.js
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| * @param {string} type - "frob" (default) ou "max" return resp. the Frobenius norm and the max norm. | ||
| * @return {number} | ||
| */ | ||
| norm(type = 'frob') { |
src/abstractMatrix.js
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| @@ -924,6 +924,25 @@ export default function AbstractMatrix(superCtor) { | |||
| } | |||
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| /** | |||
| * Returns the norm of a matrix. | |||
| * @param {string} type - "frob" (default) ou "max" return resp. the Frobenius norm and the max norm. | |||
src/abstractMatrix.js
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| var result = 0; | ||
| if (type === 'max') { | ||
| return this.max(); | ||
| } else { // by default, norm = "frobenius" |
src/abstractMatrix.js
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| } | ||
| return Math.sqrt(result); | ||
| } | ||
| } |
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else {
throw new RangeError(`unknown norm type: ${type}`);
}
| @@ -110,6 +110,16 @@ describe('utility methods', () => { | |||
| expect(() => m2.det()).toThrow(/square/); | |||
| }); | |||
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| it('norm Frobenius', () => { | |||
| var m1 = new Matrix([[1, 1, 1], [3, 3, 3], [1, 1, 1]]); | |||
| expect(m1.norm()).toBeCloseTo(5.7445626465380286, 2); | |||
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maybe add a case where "frobenius" is passed explicitly
src/abstractMatrix.js
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| } else { // by default, norm = "frobenius" | ||
| for (var i = 0; i < this.rows; i++) { | ||
| for (var j = 0; j < this.columns; j++) { | ||
| result = result + Math.abs(this.get(i, j)) * Math.abs(this.get(i, j)); |
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You don't need to take the absolute value. The square value will always be positive.
targos
approved these changes
Jul 18, 2017
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Feature which enables to do A.norm() or A.norm("max") to compute the Frobenius norm or the max norm of the Matrix A.