Help optimize code. Having trouble with eval, any better solutions?

Hi! I am trying to optimize a code and I could use some help. I ran the profiler and the eval function takes the most amount of time. I have to loop the code many times so any help speeding things up will be appreciated. The code below is a simple example of the part that takes the longest to execute. The code is pretty straight forward but anywho, I basically want to evaluate a function at a specific point as fast as possible. I have tried subs and matlabFunction but that didn't speed things up.

 x = sym('x',[2,1]);
 f = [x(1)-x(1)*cos(x(2)), x(2)-3*x(2)^2*cos(x(1))];
 J = jacobian(f,x);
 x0 = [2,1];
 N=length(x0); % Number of equations

 %%Transform into string
 fstr = map2mat(char(f));
 Jstr = map2mat(char(J));

 % replace every occurence of 'xi' with 'x(i)'
 Jstr = addPar(Jstr,N);
 fstr = addPar(fstr,N);

 x = x0;

 phi0 = eval(fstr)
 J    = eval(Jstr)

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 function str = addPar(str,N)

 % pstr = addPar(str,N)
 % Transforms every occurence of xi in str into x(i)
 % N is the maximum value of i
 % replace every occurence of xi with x(i)
 % note that we do this backwards to avoid x10 being
 % replaced with x(1)0

 for i=N:-1:1
    is = num2str(i);
    xis = ['x' is];
    xpis = ['x(' is ')'];
    str = strrep(str,xis,xpis);
 end

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 function r = map2mat(r)

 % MAP2MAT Maple to MATLAB string conversion.
 % Lifted from the symbolic toolbox source code
 %   MAP2MAT(r) converts the Maple string r containing
 %   matrix, vector, or array to a valid MATLAB string.
 %
 %   Examples: map2mat(matrix([[a,b], [c,d]])  returns
 %             [a,b;c,d]
 %             map2mat(array([[a,b], [c,d]])  returns
 %             [a,b;c,d]
 %             map2mat(vector([[a,b,c,d]])  returns
 %             [a,b,c,d]
 % Deblank.

 r(findstr(r,' ')) = [];

 % Special case of the empty matrix or vector
 if strcmp(r,'vector([])') | strcmp(r,'matrix([])') | ...
   strcmp(r,'array([])')
   r = [];
else
   % Remove matrix, vector, or array from the string.
   r = strrep(r,'matrix([[','['); r = strrep(r,'array([[','[');
   r = strrep(r,'vector([','['); r = strrep(r,'],[',';');
   r = strrep(r,']])',']'); r = strrep(r,'])',']');
end

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