MATLAB: Converting 2×1 Symbolic array to 2×1 Numeric matrix in Matlab

fileconversionMATLABmatrixsymbolicsymbolic2numeric

I have a 2×1 symbolic array (2×1 sym):
C =
    -(l1*(- l2*m2*sin(fi1 - fi2)*fidot2^2 + gr*m1*sin(fi1) + 2*gr*m2*sin(fi1)))/2
                         -(l2*m2*(l1*sin(fi1 - fi2)*fidot1^2 + gr*sin(fi2)))/2
here l1, l2, fi1, fi2, gr and etc. are symbolic variables.
I need to convert C symbolic array to 2×1 numeric matrix in a separate function tab in Matlab, where l1, l2, fi1, fi2 and etc. are given already.
I made a txt file with following commands:
smth=char(C);
    fileID = fopen('C.txt','rt');
    fprintf(fileID,'%s',smth);
    fclose(fileID);
and it made a txt file with following content:
 matrix([[-(l1*(gr*m1*sin(fi1) + 2*gr*m2*sin(fi1) - 
    fidot2^2*l2*m2*sin(fi1 
    - fi2)))/2], [-(l2*m2*(gr*sin(fi2) + fidot1^2*l1*sin(fi1 - fi2)))/2]])
But, I couldn't find a way to convert it back to numeric matrix.
What could be a way to convert symbolic matrix to numeric matrix?

Best Answer

As madhan ravi said, use the subs function. Its whole purpose is to substitute values for symbolic variables into an expression. Alternately, if you want to convert the symbolic expression into a function file that you can call with values for the variables, use the matlabFunction function to generate that function file.
Related Question