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: chop.m
    path of file: ./repos/chop
    
    the code of the file until where you have to start completion: function [c,options] = chop(x,options)
%CHOP    Round matrix elements to lower precision.
%   CHOP(X,options) is the matrix obtained by rounding the elements of

    
function [c,options] = chop(x,options)
%CHOP    Round matrix elements to lower precision.
%   CHOP(X,options) is the matrix obtained by rounding the elements of
%   the real array X to a lower precision arithmetic with one of several
%   forms of rounding.  X should be single precision or double precision
%   and the output will have the same type.  The structure options
%   controls various aspects of the rounding.
%   1. The arithmetic format is specified by options.format, which is one of 
%       'q43', 'fp8-e4m3'       - NVIDIA quarter precision (4 exponent bits,
%                                 3 significand (mantissa) bits),
%       'q52', 'fp8-e5m2'       - NVIDIA quarter precision (5 exponent bits,
%                                 2 significand bits),
%       'b', 'bfloat16'         - bfloat16,
%       'h', 'half', 'fp16'     - IEEE half precision (the default),
%       's', 'single', 'fp32'   - IEEE single precision,
%       'd', 'double', 'fp64'   - IEEE double precision,
%       'c', 'custom'           - custom format.
%      The custom (base 2) format is defined by options.params, which is a
%      2-vector [t,emax] where t is the number of bits in the significand
%      (including the hidden bit) and emax is the maximum value of the
%      exponent.  The minimu exponent is taken to be emin = 1 - emax and
%      the IEEE floating-point number representation is assumed, so that
%      emax and the number of  bits e in the exponent are related by
%      emax = 2^(e-1) - 1.  The values of t and emax are built-in forthe 
%      other formats and will automatically be returned in options.params.
%      options.format = 'd' is intend