Envelope of I/Q data

In finding the envelope of the I/Q data set (which is a complex data set, Inphase /Quadrature data) I cannot use envelop(x) in MATLAB, as it requires the real-valued "X" in MATLAB, so got an error. Does anyone have a suggestion for solving this, finding envelope from I/Q data? Thanks,

If your signal is an analytical signal, then envelope(real(X)) would simply be your answer. This would be identical to using the Hilbert transform to extract the Quadrature part of the signal from the Inphase part. If your signal is not analytical, your envelope would simply be: $$G = \sqrt{I^2 + Q^2}$$