eigsPlus provides an enhanced, alternative version to the MATLAB routine
        eigs, supported on
        MATLAB R2012b and later and Octave, providing the following
        features:
        
eigs routine,
                which will return the eigenvalues as a diagonal matrix when
                eigenvectors are always requested.
            eigs would throw an error; on these versions,
                eigsPlus will instead throw a warning.
                On R2017a, eigs also adopted the same convention of
                throwing a warning instead of an error.  However, on R2017b,
                eigs no longer throws a warning or an error.  To
                maintain consistency, as of R2017b, eigsPlus also
                no longer throws a warning. Recall in the case that no Ritz
                value converges, the returned eigenvalues and eigenvectors will
                be empty.
            flag, has been
                repurposed to return the number of iterations that is incurred;
                the user can always equivalently check if the number of
                eigenvalues returned is less than what the user requested by
                checking the dimensions of the eigenvalue and/or eigenvector
                output arguments.
                For R2017a and earlier, this is the number of ARPACK iterations.
                On newer releases, this is the number of Krylov Schur iterations
                but note that for problems with symmetric positive definite B
                matrices using shift-invert, the Krylov Schur method may be
                restarted once, if the first fails; in this case, the number of
                iterations is the sum of two attempts.
            opts.isreal = false to force the complex ARPACK
                routines to be used even if matrix A is real and opts.v0 is either
                real or complex.  MATLABs's eigs would throw an error in either of
                these cases.  eigsPlus will throw an error in either of these cases
                if opts.isreal is either not provided or if it is set to true.
            
patch command, supporting
                    patches created with diff -u, must
                    be available on the system terminal
                md5 command must also be available on the
                    system terminal
                patch and md5
            commands should already be present.
            Windows users may need to install these tools themselves.
            
        
                        makeEigsPlus();
                    
                    to install eigsPlus for the currently running version of
                    MATLAB.  It will either print a confirmation of successful
                    installation or throw an error detailing why eigsPlus
                    could not be installed.
                makeEigsPlus() to update your
                eigsPlus installation.  The eigsPlus command
                will throw an error if eigsPlus is not installed for
                the currently running version of MATLAB.
            
                help eigsPlus
                help makeEigsPlus
                help cleanEigsPlus
            
        eigs, call the
            eigsPlus command, which share identical input arguments.
            While the output arguments of eigsPlus are not exactly
            identical to the output arguments of eigs, migrating preexisting
            code should still be extremely straightforward.
            
                Note that the first call to
                eigsPlus may be a slightly longer than subsequent
                calls, due to initialization cost.  Though this is likely
                to be insignificant, it is nonetheless prudent to make sure
                eigsPlus is called at least once before conducting
                sensitive timing experiments.
            
        If you publish work that either refers to or makes use of
        eigsPlus, please cite both its name and version number,
        e.g. eigsPlus v2.1.  Note that eigsPlus, in monospaced
        font, refers to the command/routine, not the name of the
        software package.
    
eigsPlus is licensed under the GNU Affero General Public License, version 3.