# Round polynomial coeff symbolic

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amin ya on 8 Jul 2019
Answered: amin ya on 8 Jul 2019
As built in Matlab lacks this, I have written a code to find coeffitients that are very small:
function symRound=coeffRounder(symExp)
% search all elements of a matrix
for i=1:size(symRound,1)
for j=1:size(symRound,2)
[C,T]=coeffs(symRound(i,j));
isSmall=logical(abs(c)<1e-16);
C(isSmall)=0;
symRound(i,j)=dot(C,T);
end
end
symRound=symExp;
end
Is there any way to avoid this and solve the problem without this function?
This is caused because of
syms x
cos(-pi/2)*x
I also used the 2nd and 3rd syntax from here:
Pi = sym(pi, 'f') %if you want it treated as 884279719003555/281474976710656
Pi = sym(pi, 'd') %if you want it treated as symbolic 3.1415926535897931159979634685442
Non of them gives 0 for
syms x
cos(-pi/2)*x
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### Accepted Answer

amin ya on 8 Jul 2019
Ok, 3rd method works strangely.
Pi = sym('pi'); %if you want it treated as symbolic
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