Question B.13.4: We also can use MATLAB to convert G(z) to G(s) when G(s) is ...

We also can use MATLAB to convert G(z) to G(s) when G(s) is not in cascade with a z.o.h. First, we create a sampled LTI transfer function, as discussed in ch13p3. The command F=d2c(H,’zoh’) transforms H(z) to F(s) in cascade with a z. o.h., where H(z) = ((z – 1)/z)z{F(s)/s}. If we consider F(s) = sG(s), the command solves for sG(s) given H(z). Finally, sG(s)/s = G(s) yields the final result. In summary, form H(z), where H(z) = ((z – 1)/z)G(z). Use F=d2c (H, ‘zoh’ ) to find F(s) = sG(s). Divide the result by s and obtain G(s). We convert G(z) = z/(z – 0.3) into G(s). You will enter T, the sampling interval, through the keyboard.