islinphase Checks given system function is linearphase or not flag = islinphase(b,a) flag = islinphase(sos) flag = islinphase(...,tol) b Coefficients of numerator polynomial of system function a Coefficients of denumerator polynomial of system function sos Second order section matrix of order Kx6 tol Tolerence in similarities between two numbers in phase response flag This function returns logical 1 if system is linear phase (flag = 1) Otherwise it returns logical 0 (flag = 0) This function takes input a System function in terms of numerator and denumerator coefficients or in second order section (sos) matrix and checks for system having Linear Phase Response or not Checking given system function is linear-phase or not \begin{eqnarray} H(z) = z^{-1} + 2 z^{-2} + 2 z^{-3} + z^{-4} \end{eqnarray}