mat: add BandDense.Norm
MODIFY
mat/band.go
mat/band.go
@@ -7,6 +7,8 @@ package mat
import (
"gonum.org/v1/gonum/blas"
"gonum.org/v1/gonum/blas/blas64"
+ "gonum.org/v1/gonum/lapack"
+ "gonum.org/v1/gonum/lapack/lapack64"
)
var (
@@ -285,6 +287,23 @@ func (b *BandDense) Zero() {
}
}
+// Norm returns the specified norm of the receiver. Valid norms are:
+// 1 - The maximum absolute column sum
+// 2 - The Frobenius norm, the square root of the sum of the squares of the elements
+// Inf - The maximum absolute row sum
+//
+// Norm will panic with ErrNormOrder if an illegal norm is specified.
+func (b *BandDense) Norm(norm float64) float64 {
+ if b.IsEmpty() {
+ panic(ErrZeroLength)
+ }
+ lnorm := normLapack(norm, false)
+ if lnorm == lapack.MaxColumnSum || lnorm == lapack.MaxRowSum {
+ return lapack64.Langb(lnorm, b.mat)
+ }
+ return lapack64.Langb(lnorm, b.mat)
+}
+
// Trace computes the trace of the matrix.
func (b *BandDense) Trace() float64 {
r, c := b.Dims()

mat: add BandDense.Norm