vecnorm: p-norm of a vector

In splus2R: Supplemental S-PLUS functionality in R

Description

Computes the p-norm of a vector

Usage

vecnorm(x, p=2)

Arguments

x	the vector whose norm is sought (either numeric or complex).
p	a number or character string indicating the type of norm desired. Possible values include real number greater or equal to 1, Inf, or character strings "euclidean" or "maximum". Default: 2.

Value

requested p-norm of input vector.

See Also

rnorm.

Examples

## compare 2-norm calculations 
x <- rnorm(100)
sqrt(sum(x*x))
vecnorm(x)

## compare 2-norm of series which sums to Inf. The 
## vecnorm returns a finite value in this case. 
x <- rep(sqrt(.Machine$double.xmax), 4)
sqrt(sum(x*x))
vecnorm(x)

## 1-norm comparison 
sum(abs(x))
vecnorm(x, p=1)

## L-infinity norm comparison 
max(abs(x))
vecnorm(x, p=Inf)

Example output

[1] 11.26178
[1] 11.26178
[1] Inf
[1] 2.681562e+154
[1] 5.363123e+154
[1] 5.363123e+154
[1] 1.340781e+154
[1] 1.340781e+154

splus2R documentation built on May 2, 2019, 5:24 p.m.