function random() {
	let seed = 12345; // fixed seed

	return function() {
		seed = ( seed * 16807 ) % 2147483647;
		return ( seed - 1 ) / 2147483646;
	};
}

const randomFix = random();

export default class Vector {
	
	constructor( length, fillValue = 0 ) {
		this.data   = new Array( length );
		for ( let i = 0 ; i < length ; i++ ) {
			this.data[ i ] = fillValue;
		}
	}

	get length() {
		return this.data.length;
	}

	static dot( a, b ) {
		let sum = 0;
		for ( let i = 0 ; i < a.length ; i++ ) {
			sum += a.data[ i ] * b.data[ i ];
		}
		return sum;
	}

	static softmax( vec ) {
		const max = Math.max( ...vec.data );
		const exps = new Array( vec.length );
		let sum = 0;
		for ( let i = 0 ; i < vec.length ; i++ ) {
			exps[ i ] = Math.exp( vec.data[ i ] - max );
			sum += exps[ i ];
		}
		const result = new Vector( vec.length );
		for ( let i = 0 ; i < vec.length ; i++ ) {
			result.data[ i ] = exps[ i ] / sum;
		}
		return result;
	}
}