Control System Toolbox™

evalfr - Evaluate frequency response at given frequency

Syntax

frsp = evalfr(sys,f)

Description

frsp = evalfr(sys,f) evaluates the transfer function of the TF, SS, or ZPK model sys at the complex number f. For state-space models with data , the result is

evalfr is a simplified version of freqresp meant for quick evaluation of the response at a single point. Use freqresp to compute the frequency response over a set of frequencies.

Example

To evaluate the discrete-time transfer function

at , type

H = tf([1 -1],[1 1 1],-1)
z = 1+j
evalfr(H,z)
ans =
  2.3077e-01 +  1.5385e-01i

Limitations

The response is not finite when f is a pole of sys.

See Also

bode, freqresp, sigma

estim

lti/exp