gnum

func Abs ¶

func Abs[N constraints.Signed](n N) N

Abs returns the absolute value of n.

For floats use math.Abs.

func Add ¶

func Add[S ~[]N, N Number](a S, b ...S) S

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

func Add1 ¶

func Add1[S ~[]N, N Number](a S, m N) S

Add1 adds m to a and returns a.

func ArgMax ¶ added in v0.5.0

func ArgMax[S ~[]E, E constraints.Ordered](s S) int

ArgMax returns the index of the maximal value in the slice or -1 if the slice is empty.

func ArgMin ¶ added in v0.5.0

func ArgMin[S ~[]E, E constraints.Ordered](s S) int

ArgMin returns the index of the minimal value in the slice or -1 if the slice is empty.

func Cast ¶

func Cast[S ~[]N, T ~[]M, N Number, M Number](a S) T

Cast casts the values of a and places them in a new slice.

func Copy ¶

func Copy[S ~[]N, N any](a S) S

Copy returns a copy of the given slice.

func Corr ¶

func Corr[S ~[]N, N Number](a, b S) float64

Corr returns the Pearson correlation between the a and b.

func Cov ¶

func Cov[S ~[]N, N Number](a, b S) float64

Cov returns the covariance of a and b.

func Diff ¶

func Diff[N Number](a, b N) N

Diff returns the non-negative difference between a and b.

func Dot ¶

func Dot[S ~[]N, N Number](a, b S) N

Dot returns the dot product of the input vectors.

func Entropy ¶

func Entropy[S ~[]N, N Number](a S) float64

Entropy returns the Shannon-entropy of a. The elements in a don't have to sum up to 1.

func ExpMean ¶ added in v1.3.0

func ExpMean[S ~[]N, N Number](a S) float64

ExpMean returns the exponential average of the slice. Non-positive values result in NaN.

func Idiv ¶ added in v0.5.0

func Idiv[T constraints.Integer](a, b T) T

Idiv divides a by b, rounded to the nearest integer.

func L1 ¶

func L1[S ~[]N, N Number](a, b S) N

L1 returns the L1 (Manhattan) distance between a and b. Equivalent to Lp(1) but returns the same type.

func L2 ¶

func L2[S ~[]N, N Number](a, b S) float64

L2 returns the L2 (Euclidean) distance between a and b. Equivalent to Lp(2).

func LogFactorial ¶ added in v1.3.0

func LogFactorial(n int) float64

LogFactorial returns an approximation of log(n!), calculated in constant time.

func Lp ¶

func Lp[S ~[]N, N Number](p int) func(S, S) float64

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

Lp(v) = (sum_i(v[i]^p))^(1/p)

func Max ¶

func Max[S ~[]N, N constraints.Ordered](s S) N

Max returns the maximal value in the slice or zero if the slice is empty.

func Mean ¶

func Mean[S ~[]N, N Number](a S) float64

Mean returns the average of the slice.

func Min ¶

func Min[S ~[]N, N constraints.Ordered](s S) N

Min returns the maximal value in the slice or zero if the slice is empty.

func Mul ¶

func Mul[S ~[]N, N Number](a S, b ...S) S

Mul multiplies a by b and returns a. b is unchanged. If a is nil, creates a new vector.

func Mul1 ¶

func Mul1[S ~[]N, N Number](a S, m N) S

Mul1 multiplies the values of a by m and returns a.

func NQuantiles ¶ added in v1.3.0

func NQuantiles[T any](a []T, n int) []T

NQuantiles returns the elements that divide the given slice into n equal parts (up to rounding), including the first and last elements.

For example, for n=2 it returns the first element, the middle, and the last element.

func Norm ¶

func Norm[S ~[]N, N constraints.Float](a S) float64

Norm returns the L2 norm of the vector.

func Ones ¶

func Ones[S ~[]N, N Number](n int) S

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

func Quantiles ¶ added in v1.3.0

func Quantiles[T any](a []T, qq ...float64) []T

Quantiles returns the elements that divide the given slice at the given ratios.

For example, 0.5 returns the middle element, 0.25 returns the element at a quarter of the length, etc. 0 and 1 return the first and last element, respectively.

func Std ¶

func Std[S ~[]N, N Number](a S) float64

Std returns the standard deviation of a.

func Sub ¶

func Sub[S ~[]N, N Number](a S, b ...S) S

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

func Sub1 ¶

func Sub1[S ~[]N, N Number](a S, m N) S

Sub1 subtracts m from a and returns a.

func Sum ¶

func Sum[S ~[]N, N Number](a S) N

Sum returns the sum of the slice.

func Var ¶

func Var[S ~[]N, N Number](a S) float64

Var returns the variance of a.