eigs (Matlab function) Subset of eigenvalues and eigenvectors

## Matlab / Scilab equivalent

Matlab | Scilab
    d = eigs(A)
    d = eigs(A, k)

    d = eigs(A, k, sigma)
        % sigma:
        % 'largestabs' (default)
        % 'smallestabs'
        % 'largestreal'
        % 'smallestreal'
        % 'bothendsreal'
        % 'largestimag'
        % 'smallestimag'
        % 'bothendsimag'
        % scalar
        % (No equivalent)
        % (No equivalent)
        % (No equivalent)

    d = eigs(A, k, sigma, Name, Value)

    d = eigs(A, k, sigma, opts)
        % opts.issym  = 1
        % opts.tol
        % opts.maxit (= 300)
        % opts.p
        % opts.v0
        % opts.disp
        % opts.fail
        % opts.spdB
        % opts.cholB
        % opts.permB
        % (No equivalent)

    d = eigs(A, B, ..)
    d = eigs(Afun, n, ..)
    [V, D] = eigs(..)
    [V, D, flag] = eigs(..)
    d = eigs(A)
    d = eigs(A, [], k)

    d = eigs(A, [], k, sigma)
        // sigma:
        // 'LM' : Largest Magnitudes (default)
        // 'SM' : Smallest Magnitudes
        // 'LR' : Largest Real parts
        // 'SM' : Smallest Real parts
        // (No equivalent)
        // 'LI' : Largest Imaginary parts (real non-symmetric or complex problems)
        // 'SI' : Smallest Imaginary parts (real non-symmetric or complex problems)
        // (No equivalent)
        // scalar
        // 'LA' : Largest Algebraic eigenvalues (real symmetric problems).
        // 'SA' : Smallest Algebraic eigenvalues (real symmetric problems).
        // 'BE' : half from each end of the spectrum (real symmetric problems).

    // No equivalent. Sets and uses the opts structure instead

    d = eigs(A, [], k, sigma, opts)
        // opts.issym   (= %t) : used with Afun
        // opts.tol
        // opts.maxiter (= 300)
        // opts.ncv       : Number of Lanczos basis vectors
        // opts.resid     : starting residual vector
        // (No equivalent)
        // (No equivalent)
        // (No equivalent)
        // opts.cholB
        // (No equivalent)
        // opts.isreal (= %t) : used with Afun

    d = eigs(A, B, ..)
    d = eigs(Afun, n, ..)
    [D, V] = eigs(..)    // D still as first output
    // No equivalent

## See also

- eig
- spec
- bdiag