vectors

func Add ¶

func Add(a []float64, b ...[]float64) []float64

Add adds b to a and returns a. b is unchanged. If a is nil, creates a new vector.

func Copy ¶

func Copy(a []float64) []float64

Copy returns a copy of the given vector.

func Dot ¶

func Dot(a, b []float64) float64

Dot returns the dot product of the input vectors.

func L1 ¶

func L1(a, b []float64) float64

L1 (Manhattan) distance. Equivalent to Lp(1).

func L2 ¶

func L2(a, b []float64) float64

L2 (Euclidean) distance. Equivalent to Lp(2).

func Lp ¶

func Lp(p int) func([]float64, []float64) float64

Lp returns an Lp distance function. Lp is calculated as follows:

Lp(v) = the p'th root of sum_i(v[i]^p)

For convenience, L1 (Manhattan)and L2 (Euclidean) are prepared package variables.

func Mul ¶

func Mul(a []float64, m float64) []float64

Mul multiplies the values of a by m and returns a.

func Norm ¶

func Norm(a []float64) float64

Norm returns the norm of the vector, in L2.

func Ones ¶

func Ones(n int) []float64

Ones returns a slice of ones of length n. Panics if n is negative.

func Sub ¶

func Sub(a []float64, b ...[]float64) []float64

Sub subtracts b from a and returns a. b is unchanged. If a is nil, creates a new vector.