package main

import (
	"math"
	"math/rand"
)

type Vector []float64

func MakeVector(n int) Vector {
	return make(Vector, n)
}

func MakeRandomVector(n int) Vector {
	V := make(Vector, n)
	for i := 0; i < n; i++ {
		for V[i] == 0 {
			V[i] = rand.NormFloat64()
		}
	}
	return V
}

func MakeDropoutVector(n int) Vector {
	V := make(Vector, n)
	for i := 0; i < n; i++ {
		if rand.Float64() >= Dropout {
			V[i] = 1 / (1 - Dropout)
		}
	}
	return V
}

func (A Vector) N() int {
	return len(A)
}

func (A Vector) Max() (int, float64) {
	id, max := 0, A[0]
	for i := 1; i < A.N(); i++ {
		if A[i] > max {
			id, max = i, A[i]
		}
	}
	return id, max
}

func (A Vector) Dot(B Vector) float64 {
	if A.N() != B.N() {
		panic("Incompatible Dimensions")
	}
	sum := 0.
	for i := 0; i < A.N(); i++ {
		sum += A[i] * B[i]
	}
	return sum
}

func (A Vector) Modulus() float64 {
	return math.Sqrt(A.Dot(A))
}