This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English version of the page.

Note: This page has been translated by MathWorks. Click here to see
To view all translated materials including this page, select Country from the country navigator on the bottom of this page.


Compute linear response characteristics


S = lsiminfo(y,t,yfinal)
S = lsiminfo(y,t)
S = lsiminfo(...,'SettlingTimeThreshold',ST)


S = lsiminfo(y,t,yfinal) takes the response data (t,y) and a steady-state value yfinal and returns a structure S containing the following performance indicators:

  • SettlingTime — Settling time

  • Min — Minimum value of Y

  • MinTime — Time at which the minimum value is reached

  • Max — Maximum value of Y

  • MaxTime — Time at which the maximum value is reached

For SISO responses, t and y are vectors with the same length NS. For responses with NY outputs, you can specify y as an NS-by-NY array and yfinal as a NY-by-1 array. lsiminfo then returns an NY-by-1 structure array S of performance metrics for each output channel.

S = lsiminfo(y,t) uses the last sample value of y as steady-state value yfinal. s = lsiminfo(y) assumes t = 1:NS.

S = lsiminfo(...,'SettlingTimeThreshold',ST) lets you specify the threshold ST used in the settling time calculation. The response has settled when the error |y(t) - yfinal| becomes smaller than a fraction ST of its peak value. The default value is ST=0.02 (2%).


collapse all

Create the following continuous-time transfer function:


sys = tf([1 -1],[1 2 3 4]);

Calculate the impulse response.

[y,t] = impulse(sys);

impulse returns the output response y and the time vector t used for simulation.

Compute the response characteristics using a final response value of 0.

s = lsiminfo(y,t,0)
s = struct with fields:
    SettlingTime: 22.8700
             Min: -0.4268
         MinTime: 2.0088
             Max: 0.2847
         MaxTime: 4.0733

You can plot the impulse response and verify these response characteristics. For example, the time at which the minimum response value (MinTime) is reached is approximately 2 seconds.


Introduced in R2006a