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Diffstat (limited to 'macros/ellipap.sci')
| -rw-r--r-- | macros/ellipap.sci | 103 |
1 files changed, 59 insertions, 44 deletions
diff --git a/macros/ellipap.sci b/macros/ellipap.sci index 7b4c1ae..d360d2e 100644 --- a/macros/ellipap.sci +++ b/macros/ellipap.sci @@ -1,46 +1,61 @@ -function [z, p, g] = ellipap (n, Rp, Rs) -//Designs a lowpass analog elliptic filter. -//Calling Sequence -//[z, p, g] = ellipap (n, Rp, Rs) -//[z, p] = ellipap (n, Rp, Rs) -//z = ellipap (n, Rp, Rs) -//Parameters -//n: Filter Order -//Rp: Peak-to-peak passband ripple -//Rs: Stopband attenuation -//Description -//This is an Octave function. -//It designs a lowpass analog elliptic filter of nth order, with a Peak-to-peak passband ripple of Rp and a stopband attenuation of Rs. -//Examples -//[z, p, g] = ellipap (5, 10, 10) -//z = -// -// 0.0000 + 2.5546i 0.0000 + 1.6835i -0.0000 - 2.5546i -0.0000 - 1.6835i -// -//p = -// -// -0.05243 + 0.63524i -0.01633 + 0.96289i -0.05243 - 0.63524i -0.01633 - 0.96289i -0.07369 + 0.00000i +// Copyright (C) 2018 - IIT Bombay - FOSSEE // -//g = 0.0015012 - -funcprot(0); -lhs = argn(1) -rhs = argn(2) -if (rhs < 3 | rhs > 3) -error("Wrong number of input arguments.") -end - -select(rhs) - - case 3 then - if(lhs==1) - z = callOctave("ellipap", n, Rp, Rs) - elseif(lhs==2) - [z, p] = callOctave("ellipap", n, Rp, Rs) - elseif(lhs==3) - [z, p, g] = callOctave("ellipap", n, Rp, Rs) - else - error("Wrong number of output argments.") - end - end +// This file must be used under the terms of the CeCILL. +// This source file is licensed as described in the file COPYING, which +// you should have received as part of this distribution. The terms +// are also available at +// http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt +// Author:Sonu Sharma, RGIT Mumbai +// Organization: FOSSEE, IIT Bombay +// Email: toolbox@scilab.in + +function [z, p, g] = ellipap (n, Rp, Rs) + //Produces a lowpass analog prototype elliptic filter. + + //Calling Sequence + //[z, p, g] = ellipap (n, Rp, Rs) + + //Parameters + //n: Filter Order + //Rp: Peak-to-peak passband ripple (in dB) + //Rs: Stopband attenuation (in dB) + + //Description + //It gives a lowpass analog elliptic prototype filter of nth order, with a Peak-to-peak passband ripple of Rp dB and a stopband attenuation of Rs dB. + + //Examples + //[z, p, g] = ellipap (4, 3,10) + //Output : + // g = + // + // 0.3162 + // p = + // + // - 0.2071 - 0.8587i + // - 0.0042 - 0.9990i + // - 0.2071 + 0.8587i + // - 0.0042 + 0.9990i + // z = + // + // - 1.3121i + // - 1.0063i + // 1.3121i + // 1.0063i + + funcprot(0); + lhs = argn(1) + rhs = argn(2) + if (rhs < 3 | rhs > 3) + error("Wrong number of input arguments.") + end + + Rpf = 10 ^ (-Rp/20); //passband pick to pick ripple in fraction + rp = 1 - Rpf ; //analpf function compitable passband ripple (delta-p) + Rsf = 10 ^ (-Rs/20); //stop band pick to pick ripple in fraction + rs = Rsf ; //analpf function compitable stop band ripple (delta-s) + [hs,p,z,g]=analpf(n,"ellip",[rp rs],1); //cutoff frequency of 1 rad/sec for prototype filter + p = p' ; + z = z' ; + g = abs(g); + endfunction |