<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:arial,helvetica,sans-serif;font-size:10pt"><div>Hi Anders,<br><br>I you plot the freq response of iir you see that the max value is around 0.75 same as your graphic shows.. I will take a closer look at the iir response.. <br><br>Regards,<br><br><span style="font-size: 10pt;">Julio Gonzalez-Saenz<br>
www.part-time-scientists.com<br>
www.neex-technologies.com</span><br></div><div style="font-family: arial,helvetica,sans-serif; font-size: 10pt;"><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><font face="Tahoma" size="2"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> Anders Sneckenborg <anders@simbalsyd.se><br><b><span style="font-weight: bold;">To:</span></b> "users@lists.scilab.org" <users@lists.scilab.org><br><b><span style="font-weight: bold;">Sent:</span></b> Thu, 15 April, 2010 7:14:38<br><b><span style="font-weight: bold;">Subject:</span></b> SV: [scilab-Users] lowpassfilter<br></font><br>
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<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);">Hi
again</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">I edited the code (removed dead code) and here it is again. It
will execute exactly as before but without the disturbing dead code. </span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">//---------------------------</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">f1 = 0.1; //Hz</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">tSamp = 0.01; //s</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">tMax = 200;</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">t = 0:tSamp:tMax;</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">y = sin(2*%pi*f1*t); </span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">Order = 1;</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">Fcutoff = 0.1;</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">Fs = 1/tSamp;</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">hz = iir(Order,'lp','butt',[Fcutoff/Fs 0],[0 0]);</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">sl = tf2ss(hz);</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">yf = flts(y,sl);</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">plot(t,y,'-b');</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">plot(t,yf,'-r');</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">//---------------------------</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US">/Anders</span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US"> </span></p>
<p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);" lang="EN-US"> </span></p>
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<p class="MsoNormal"><b><span style="font-size: 10pt; font-family: "sans-serif";">Från:</span></b><span style="font-size: 10pt; font-family: "sans-serif";"> Julio
Gonzalez-Saenz [mailto:julio.gonzalez@ymail.com] <br>
<b>Skickat:</b> den 14 april 2010 22:42<br>
<b>Till:</b> users@lists.scilab.org<br>
<b>Ämne:</b> Re: [scilab-Users] lowpassfilter</span></p>
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<p class="MsoNormal"><span style="font-size: 10pt;">Hi Anders,<br>
<br>
Can you please double check the semicolon on the function y definition? You
also have a f1 and f2 but only f1 is defined..<br>
<br>
Regards,<br>
<br>
<br>
Julio Gonzalez-Saenz<br>
www.part-time-scientists.com<br>
www.neex-technologies.com</span></p>
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<p class="MsoNormal"><span style="font-size: 10pt;"> </span></p>
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<p class="MsoNormal"><span style="font-size: 10pt;"> </span></p>
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<p class="MsoNormal" style="margin-bottom: 12pt;"><b><span style="font-size: 10pt; font-family: "sans-serif";">From:</span></b><span style="font-size: 10pt; font-family: "sans-serif";"> Anders Sneckenborg
<anders@simbalsyd.se><br>
<b>To:</b> "users@lists.scilab.org" <users@lists.scilab.org><br>
<b>Sent:</b> Wed, 14 April, 2010 22:19:29<br>
<b>Subject:</b> [scilab-Users] lowpassfilter </span><span style="font-size: 12pt; font-family: "serif";"></span></p>
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<p class="MsoNormal">Hi</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><span lang="EN-US">When running the following script I
expected the filtered signal to have an amplitude of 0.5. </span></p>
<p class="MsoNormal"><span lang="EN-US">My intention was to lowpassfilter a signal
with the same frequency as the cutoff frequency. Am I doing something
wrong? </span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">//---------------------------</span></p>
<p class="MsoNormal"><span lang="EN-US">f1 = 0.1;
//Hz</span></p>
<p class="MsoNormal"><span lang="EN-US">tSamp = 0.01; //s</span></p>
<p class="MsoNormal"><span lang="EN-US">tMax = 200;</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal">t = 0:tSamp:tMax;</p>
<p class="MsoNormal">y = 1*sin(2*%pi*f1*t); + 0.5*sin(2*%pi*f2*t);</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">Order = 1;</p>
<p class="MsoNormal">Fcutoff = 0.1;</p>
<p class="MsoNormal">Fs = 1/tSamp;</p>
<p class="MsoNormal">hz = iir(Order,'lp','butt',[Fcutoff/Fs 0],[0 0]);</p>
<p class="MsoNormal"><span lang="EN-US">sl = tf2ss(hz);</span></p>
<p class="MsoNormal"><span lang="EN-US">yf = flts(y,sl);</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">plot(t,y,'-b');</span></p>
<p class="MsoNormal"><span lang="EN-US">plot(t,yf,'-r');</span></p>
<p class="MsoNormal"><span lang="EN-US">//---------------------------</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">Best regards</span></p>
<p class="MsoNormal"><span lang="EN-US">Anders</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
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<p class="MsoNormal"><span style="font-size: 12pt; font-family: "serif";"> I</span></p>
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