impinvar This function converts analog filter with coefficients b and a to digital, conserving impulse response. [b, a] = impinvar (b, a) [b, a] = impinvar (b, a, fs) [b, a] = impinvar (b, a, fs, tol) b: real or complex valued scalar or vector a: real or complex valued scalar or vector, order should be greater than b fs: real or complex value, default value 1Hz tol: real or complex value, default value 0.0001 This is an Octave function. This function converts analog filter with coefficients b and a to digital, conserving impulse response. This function does the inverse of impinvar.