You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: strsub.m
    path of file: ./repos/mpsim/lib/util/type
    
    the code of the file until where you have to start completion: function out = strsub (in, ind, len)

    
function out = strsub (in, ind, len)
%STRSUB: Extract substrings in input string.
%   OUT = STRSUB(IN, IND, LEN) returns the substring starting at initial 
%   index IND and optional length LEN.  The input string IN can be a cell
%   array, in which case the indices IND, LEN can be vectors. See examples
%   at the bottom.

    if ~iscell(in)
        if isvector(in)
            if (nargin < 3)
                out = in(ind:end