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: tm_ct_to_dps.m
    path of file: ./repos/md-dmri/tools/tensor_maths
    
    the code of the file until where you have to start completion: function dps = tm_ct_to_dps(ct, dps, f_reshape, reg)
% function dps = tm_ct_to_dps(dt, dps, f_reshape)

    
function dps = tm_ct_to_dps(ct, dps, f_reshape, reg)
% function dps = tm_ct_to_dps(dt, dps, f_reshape)
%
% ct  - diffusion tensor covariance 4th order tensor(s) in 1x21 format
% dps - display parameter structure
%
% optional
% f_reshape - function to reshape output parameters
% reg       - regularization parameter
%
% output:
% dps.(V_MD, V_iso, VM_MD1, V_iso1, V_shear, V_shear1, ...
%        C_MD, C_mu, C_M, C_c, K_bulk, K_shear, MK, K_mu)

if (nargin < 2), dps = []; end