MATLAB: I have a problem with unwrap

errorsignalunwrap

I want to plot phase of a signal with unwrap code but when i run it, matlab shows me this error:
Error using sym/diff (line 36)
The second and third arguments must either be variables or a variable and a nonnegative integer
specifying the number of differentiations.
Error in unwrap>LocalUnwrap (line 85)
dp = diff(p,1,1); % Incremental phase variations
Error in unwrap (line 65)
q(indf,j) = LocalUnwrap(p(indf,j),cutoff);
Error in Q1 (line 40)
unwrap(phase_1)
How can I fix this problem?

Best Answer

unwrap() is only defined for numeric values, not for symbolic values.