Update README.md

README.md

@@ -15,14 +15,16 @@ import tfest
 # y: output
 te = tfest.tfest(u, y)
 # n_zeros, n_poles
-te.estimate(3, 4)
+te.estimate(3, 4, time=1)
 te.get_transfer_function()
 ```
+"time" is simulation length in seconds.
 To plot its bode diagram:
 ```python
 te.plot_bode()
 ```
-Default method to calculate the frequency response Y/U is cross density/ power density, if you want to use frequency/frequency just set the method to "fft" and specify the time length of the simulation (in seconds, default is 1):
+Default method to calculate the frequency response Y/U is H1 estimator, if you want to use H2 or frequency/frequency just set the method to "h2" or "fft" and specify the time length of the simulation (in seconds, default is 1):
 ```python
+te.estimate(3, 4, method="h2", time=1)
 te.estimate(3, 4, method="fft", time=1)
-```
+```