Help with MuPAD function (stats::covariance) error at Matlab

JP
2017 3 2
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更新时间：2017 3 2
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My code is below. Could you help me to avoid the below error?
syms x1 y1 x2 y2;
z=feval(symengine,'stats::covariance',[x1, y1],[x2, y2]);
>> ex
Error using mupadengine/feval (line 163)
Some data are of invalid type.
Error in ex (line 2)
z=feval(symengine,'stats::covariance',[x1, y1],[x2, y2]);

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Walter Roberson
Walter Roberson 2017-3-2

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This requires an advanced symbolic toolbox trick.
symLIST = @(varargin)feval(symengine,'DOM_LIST',varargin{:});
syms x1 y1 x2 y2
z = feval(symengine, 'stats::covariance', symLIST(x1, y1), symLIST(x2, y2));
when you see a MuPAD call documented with [] around the argument, then that is a DOM_LIST argument and you have to construct that specially from MATLAB. When you try to use normal [] list and pass that to MuPAD then what gets passed is DOM_MATRIX

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JP
JP 2017-3-2
Dear Walter Roberson; Thank you very much. Based on your answer, I changed my code a bit. But again, I have an error message. Could you help me figure out what's wrong? Thank you in advance!
symMATRIX= @(varargin)feval(symengine,'DOM_MATRIX',varargin{:});
syms m x;
r1=normrnd(0,1,[1,2]);
r2=normrnd(0,1,[1,2]);
x1=m*r1;
y1=x*r2 + m*r1;
z = feval(symengine, 'stats::covariance', symMATRIX(x1), symMATRIX(y1));
>>
Error using mupadengine/feval (line 163)
The number of data is incorrect.
Error in ex1 (line 8)
z = feval(symengine, 'stats::covariance', symMATRIX(x1), symMATRIX(y1));
Walter Roberson
Walter Roberson 2017-3-2
you need to use DOM_LIST for the interference

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