# How do I make fprintf to show symbolic math?

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Rustem on 14 Feb 2018
Commented: Walter Roberson on 28 May 2020
I am solving for sigma_y and I used the solve function and symbolic math. In the end I need fprintf to display the formula in the form 'v*sigz', but it doesn't do this with the current fprintf. The pictures are there to better explain what I am doing.
syms epsy E sigy v sigx sigz
epsy = 0
sigx = 0
eqn = epsy == (1/E)*(sigy-(v*(sigx+sigz)))
sigy = solve(eqn,sigy)
fprintf('%0.2f mm.\n',sigy)

Walter Roberson on 14 Feb 2018
fprintf('%s mm.\n', char(sigy))
##### 2 CommentsShowHide 1 older comment
Walter Roberson on 25 May 2020
You cannot fprintf symbolic expressions in "pretty" formats. fprintf can only output characters in the first 16 bits of the Unicode planes.
https://www.compart.com/en/unicode/U+2093 shows subscript x in Unicode. However there is no subscript y.
Anything like the tall { cannot be created in Unicode.
The closest you can get in such cases is to emit encodings of the equations, such as using latex or MathML.

Lam Nguyen Van on 28 May 2020
Help me! I want to creat a Symbolic Matrix:
A = [ε ε ε;
ε ε ε]
I used the command, but:
syms A epsilon
epsilon = [ char(949) char(949) char(949)
char(949) char(949) char(949) ]
epsilon (2)
epxilon = sym('epsilon', [2 3])
A = zeros (2, 3);
for i = 1:6
epsilon = char(949);
A(i) = epsilon;
end
A
Walter Roberson on 28 May 2020
You cannot do it in a nicely printable form in normal MATLAB .m files.
However in Live Script, you get a nice display if you use
syms epsilon
A = ones(2,3) * epsilon