CODEWITHSUNDEEP
rmathvector
Peter Linton
Peter Linton

Reputation: 11

L_0 norm in R, how to perform

Does anyone know how to calculate the L_0 norm of a vector in R. You can't do the usual sum(x^p)^(1/p) when p=0 so I was unsure if there was an easy way to do this. Thanks!

Upvotes: 1

Views: 601

Answers (1)

Love-R
Love-R

Reputation: 818

It really depends how you define the L_0 norm. There is not a clear consensus.

From wikipedia: ℓ0 "norm" by David Donoho — whose quotation marks warn that this function is not a proper norm — is the number of non-zero entries of the vector x. Many authors abuse terminology by omitting the quotation marks. Defining 0^0 = 0,

just use sum(x != 0)

Upvotes: 4

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