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<font face="Courier New">Dear All,<br>
<br>
I need to have examples of rationals with very close poles and
zeros, but the simp engine simplifies them. This is awkward, since
the simp documentation says there is no threshold, so other than
identical poles and zeros shouldn't be simplified. Actually this
is the case with complicated rationals created from electrical
network analysis of some filters, but not with the more
transparent example below.<br>
<br>
My second attempt to reproduce the problem in my simple numeric
example has been to use the command simp_mode to disable any
simplification. But it doesn't work as expected--and described.
For instance</font><span style="color:rgb(0,0,0);"></span><span
style="color:rgb(0,0,0);">, the code<br>
<br>
N</span> <span style="color:rgb(92,92,92);">=</span> <span
style="color:rgb(50,185,185);">poly</span><span
style="color:rgb(74,85,219);">(</span><span
style="color:rgb(74,85,219);">[</span><span
style="color:rgb(188,143,143);">1</span> <span
style="color:rgb(188,143,143);">2</span> <span
style="color:rgb(188,143,143);">3</span> <span
style="color:rgb(188,143,143);">3.000009</span> <span
style="color:rgb(188,143,143);">5</span><span
style="color:rgb(74,85,219);">]</span><span
style="color:rgb(0,0,0);">,</span> <span
style="color:rgb(188,143,143);">"</span><span
style="color:rgb(188,143,143);">s</span><span
style="color:rgb(188,143,143);">"</span><span
style="color:rgb(74,85,219);">)</span><span
style="color:rgb(0,0,0);"><br>
D</span> <span style="color:rgb(92,92,92);">=</span> <span
style="color:rgb(50,185,185);">poly</span><span
style="color:rgb(74,85,219);">(</span><span
style="color:rgb(74,85,219);">[</span><span
style="color:rgb(188,143,143);">1.0000001</span> <span
style="color:rgb(188,143,143);">3.0000003</span> <span
style="color:rgb(188,143,143);">4</span> <span
style="color:rgb(188,143,143);">6</span><span
style="color:rgb(74,85,219);">]</span><span
style="color:rgb(0,0,0);">,</span> <span
style="color:rgb(188,143,143);">"</span><span
style="color:rgb(188,143,143);">s</span><span
style="color:rgb(188,143,143);">"</span><span
style="color:rgb(74,85,219);">)</span><span
style="color:rgb(50,185,185);"><br>
simp_mode</span> <span style="color:rgb(188,143,143);">=</span> <span
style="color:rgb(188,143,143);">%f</span><span
style="color:rgb(0,0,0);">;</span><span style="color:rgb(0,0,0);"><br>
H</span> <span style="color:rgb(92,92,92);">=</span> <span
style="color:rgb(0,0,0);">N</span><span
style="color:rgb(92,92,92);">/</span><span
style="color:rgb(0,0,0);">D</span><span style="color:rgb(0,0,0);"></span><br>
<br>
yields these results:<br>
<br>
--> N<br>
N = <br>
-90.00027 +213.00055s -184.00037s² +74.000099s³ -14.000009s⁴ +s⁵<br>
--> D<br>
D = <br>
72.000014 -126.00002s +67.000005s² -14s³ +s⁴<br>
--> H<br>
H = <br>
<br>
-30.000093 +31.000066s -10.00001s² +s³ <br>
-------------------------------------- <br>
24.000006 -10.000001s +s² <br>
<br>
As can be seen, even if I disabled automatic simplification, the
result is not the raw quotient N/D but a "simplified" version.<br>
<br>
Any idea? Is it a bug?<br>
<br>
Regards,<br>
<br>
Federico Miyara <br>
<span style="color:rgb(0,0,0);"></span>
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