| minkowski {fastmatrix} | R Documentation |
Computes a p-norm of vector x using BLAS. The norm can be the one (p = 1)
norm, Euclidean (p = 2) norm, the infinity (p = Inf) norm. For other
values p >= 1 the underlying Fortran code is based on ideas of BLAS Level 1.
minkowski(x, p = 2)
x |
a numeric vector. |
p |
a number, specifying the type of norm desired. Possible values include
real number greater or equal to 1, or Inf, Default value is |
Method of minkowski calls BLAS functions dasum (p = 1), dnrm2
(p = 2), idamax (p = Inf). For other values, a Fortran subroutine
using unrolled cycles is called.
The vector p-norm, a non-negative number.
# a tiny example x <- rnorm(1000) minkowski(x, p = 1) minkowski(x, p = 1.5) minkowski(x, p = 2) minkowski(x, p = Inf) x <- x / minkowski(x) minkowski(x, p = 2) # equal to 1