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Scilab Help >> Linear Algebra > Matrix Analysis > rank

rank

rank

Syntax

[i]=rank(X)
[i]=rank(X,tol)

Arguments

X

real or complex matrix

tol

nonnegative real number

Description

rank(X) is the numerical rank of X i.e. the number of singular values of X that are larger than norm(size(X),'inf') * norm(X) * %eps.

rank(X,tol) is the number of singular values of X that are larger than tol.

rank([]) returns 0.

The default value of tol is proportional to norm(X). As a consequence rank([1.d-80,0;0,1.d-80]) is 2 !.

Examples

rank([1.d-80,0;0,1.d-80])
rank([1,0;0,1.d-80])

See also


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