为什么 savepath 在 Matlab 中重置用户路径？

Question

条件：不成功userpath与addpath和savepath
差异条件：无法在此处以 sudo/root 身份启动 Matlab
支持： MATLAB 不打算由超级用户- 服务台运行。
设置

echo "export MATLAB_USE_USERWORK=1" >> $HOME/.bashrc    
matlab -nodesktop -nosplash -r \ 
    "userpath('/home/masi/Documents/bin/matlab/'); exit;"

导致用户userpath为空的情况（ '' ）

• 测试代码 1

   userpath('/home/masi/Documents/bin/matlab/') home='/home/masi/'; savepath(fullfile(home, 'pathdef.m')); % ~/pathdef.m originally but reject because expansion of ~ not working userpath

  输出

  ''

  预期输出

  '/home/masi/Documents/bin/matlab/:'

  启动 Matlab 后从 Matlab 的提示中完成重复

  >> userpath ans = /home/masi/Documents/bin/matlab/: >> home='/home/masi/'; >> savepath(fullfile(home, 'pathdef.m')); >> userpath ans = ''

• 测试代码2

   if (userpath == '') userpath('/home/masi/Documents/bin/matlab/') addpath('/home/masi/Documents/Math/') savepath '/home/masi/pathdef.m' end % Visualising path in Home > Environment > Set Path

  输出： /home/masi/Documents/Math/留在路径中，但/home/masi/Documents/bin/matlab/不在。 预期输出：都留在路径中。

• 测试代码 3

   % Edit the Matlab preference file as root. [Kusalananda] % My startup.m userpath('/home/masi/Documents/bin/matlab/') addpath('/home/masi/Documents/Math/') savepath '/home/masi/startup.m' % Visualising path in Home > Environment > Set Path

  输出： /home/masi/Documents/Math/留在路径中，但/home/masi/Documents/bin/matlab/不在。 预期输出：都留在路径中。

• 测试代码 4

   % Use MATLABPATH environment variable instead. [Kusalananda]

  如何？

MATLAB：2016a
系统：Linux Ubuntu 16.04 64 位
硬件：Macbook Air 2013-mid
相关：在 Linux 中设置 wfdb此处官方脚本不完整

Answer 1

我无法稳定地维护系统中的用户userpath ，因此在功能开始时起作用的解决方案

checkSystemMemory();    
%% TODO Virtual memory; enable virtual memory on HDDs.
% http://askubuntu.com/q/799834/25388 

home=char(java.lang.System.getProperty('user.home')); % all systems
if (isempty(userpath))
    userpath(fullfile(home, 'Documents/bin/matlab/') ) 
    % list software locations in the project location
    addpath(fullfile(home, 'Documents/Math/') )
    % list software locations in the centralised location
    addpath(fullfile(home, 'Documents/Programming/Matlab/export_fig-master/') )

    % http://stackoverflow.com/a/38188945/54964
    if ( not( com.mathworks.services.Prefs.getStringPref('CurrentKeyBindingSet') == 'Windows' ) ) 
        com.mathworks.services.Prefs.setStringPref('CurrentKeyBindingSet', 'WindowsDefaultSet.xml')
    end 

    % Event errors else with touchpad scroll
    !synclient HorizTwoFingerScroll=0

    %savepath '/home/masi/pathdef.m'
    savepath(fullfile(home, 'startup.m'));
end

function checkSystemMemory()
%% Java for rdsamp - restart for the change to take effect if necessary.
% https://physionet.org/physiotools/matlab/wfdb-app-matlab/faq.shtml
% http://se.mathworks.com/matlabcentral/answers/92813-how-do-i-increase-the-heap-space-for-the-java-vm-in-matlab-6-0-r12-and-later-versions
% http://stackoverflow.com/a/35971040/54964
isSetHeapSizeMemoryMax = com.mathworks.services.Prefs.getIntegerPref('JavaMemHeapMax');  % MB
if (isSetHeapSizeMemoryMax < 2000)
    com.mathworks.services.Prefs.setIntegerPref('JavaMemHeapMax', 2048); % MB
    fprintf('Quitting Matlab Function because memory %d is insufficient.', ...
         isSetHeapSizeMemoryMax);
    return
end
assert(java.lang.Runtime.getRuntime.maxMemory/1e9 >= 1.9, 'Java heap size too small');

end