On Fri, Jul 31, 2020 at 3:28 PM shall689 <sahallacy@hotmail.com> wrote:
Hello,
I am using Octave 5.2 and control pkg 3.2.0. When I try to plot the step
response of a transfer funciton, octave is returning error: set:
"dataaspectratio' must be finite. It also returns "warning:
opengl_renderer: data values greater than float capacity. (1) scale data, or
(2) use gnuplot.
The octave I am using only has two available graphics toolkits: qt and fltk.
graphic_toolkit() returns qt.
What is the best way to fix this issue?
I don't have Octave on the computer that I am using to type this message, so
I don't have the exact transfer function, so I manually copied the transfer
function (shown below).
4.63e-12s^7+1.346e-07*s^6-0.02167*s^5-632.2*s^4+1.04e8*s^3
+3.035e12*s^2+1.284e16*s+3.225e20
---------------------------------------------------------------------------------------------------------------
6.25e-18*s^8+6.136e-12*s^7+2.875e-7*s^6-0.01399*s^5-448.9*s^4+1.057e8*s^3+3.068e12*s^2+1.293e16*s+3.241e20
Stephen
6.25e-18 is so small.
The 2nd point is:
In control theory there are dominant poles and zeros and non dominant ones.
I would suggest that you disregard the poles that are far away from the origin.