Revision: 303
http://sourceforge.net/p/python-control/code/303
Author: repa
Date: 2014-07-06 17:06:44 +0000 (Sun, 06 Jul 2014)
Log Message:
-----------
Slightly increase the epsilon value for margin computation frequency,
many type 2 systems (on Windows, 32 bit pythonxy, but not on 64 bit Linux
which I tested on) got cross over margins calculated at frequencies
around 1e-11
Modified Paths:
--------------
trunk/src/margins.py
Modified: trunk/src/margins.py
===================================================================
--- trunk/src/margins.py 2014-06-16 08:38:23 UTC (rev 302)
+++ trunk/src/margins.py 2014-07-06 17:06:44 UTC (rev 303)
@@ -80,13 +80,14 @@
# idea for the frequency data solution copied/adapted from
# https://github.com/alchemyst/Skogestad-Python/blob/master/BODE.py
# Rene van Paassen <ren...@gm...>
-def stability_margins(sysdata, deg=True, returnall=False, epsw=1e-12):
+def stability_margins(sysdata, deg=True, returnall=False, epsw=1e-10):
"""Calculate gain, phase and stability margins and associated
crossover frequencies.
Usage
-----
- gm, pm, sm, wg, wp, ws = stability_margins(sysdata, deg=True)
+ gm, pm, sm, wg, wp, ws = stability_margins(sysdata, deg=True,
+ returnall=False, epsw=1e-10)
Parameters
----------
@@ -101,7 +102,7 @@
returnall=False: boolean
If true, return all margins found. Note that for frequency data or
FRD systems, only one margin is found and returned.
- epsw=1e-12: float
+ epsw=1e-10: float
frequencies below this value are considered static gain, and not
returned as margin.
@@ -114,7 +115,7 @@
one crossover frequency is detected, returns the lowest corresponding
margin.
When requesting all margins, the return values are array_like,
- and all margins are returns for linear systems not equal to FRD
+ and all margins are returned for linear systems not equal to FRD
"""
try:
|
