Scilab IIR filter, Bode plot trouble

Started by msvilans.dsp in comp.dsp8 years ago 5 replies

Dear Comp.DSP, I am using Scilab 5.3.0 (64-bit) to experiment with digital IIR filter design. When I create a Bode plot of the filter...

Dear Comp.DSP, I am using Scilab 5.3.0 (64-bit) to experiment with digital IIR filter design. When I create a Bode plot of the filter response, the magnitudes don't appear to make sense. I created a low pass filter, and plotted the magnitudes on a linear scale, using the frmag() function. The response for the passband frequencies was at 1.0, as expected. In a Bode plot of the same function, ...


Scilab question: cat takes too long w/ large amounts of data, what's an alternative function?

Started by maxplanck in comp.dsp12 years ago 1 reply

In Scilab, I'm using cat in a for loop to concatenate column matrices produced by the for loop. The problem is that since i'm working with audio...

In Scilab, I'm using cat in a for loop to concatenate column matrices produced by the for loop. The problem is that since i'm working with audio data, the matrices are long, and cat takes longer every time the for loop runs because it's handling more data each time the for loop runs. Are there any alternative functions that i could use instead of cat, which will be faster? Perhaps a funct...


Frecuency response and Scilab

Started by cpbasur in comp.dsp10 years ago

I updated the web: Problems and examples of frequency response (Bode diagram, Nyquist diagram, phase margin, gain margin, lead compensator,...

I updated the web: Problems and examples of frequency response (Bode diagram, Nyquist diagram, phase margin, gain margin, lead compensator, lag compensator, lag-lead, Nichols chart, static velocity constant error, resonant peak magnitude, resonant peak frequency, bandwidth) by Scilab (bode, syslin, logspace, nyquist, g_margin, p_margin, show_margins,repfreq, dbphi, tf2ss, chart, black, m_circle, ...


Re: fftw and derivative. once again

Started by Jerry Avins in comp.dsp8 years ago

On Sunday, January 9, 2011 6:52:09 PM UTC-5, Tim Wescott wrote: ... > You're not using any frequency limiting -- are you sure you're not...

On Sunday, January 9, 2011 6:52:09 PM UTC-5, Tim Wescott wrote: ... > You're not using any frequency limiting -- are you sure you're not just > amplifying the heck out of your noise? > > In Scilab: > > --> N = 4096; n = 0:N-1; > > --> nn = pmodulo(n + N/2, N) - N/2; > > --> x = exp(-nn.^2 / 100000); xd = ifft(fft(x) .* (-nn .^ 2)); > > --> clf; plot2d(n, [x' xd']) > > gives


Re: OT:advise for developing Codecs

Started by Jerry Avins in comp.dsp8 years ago

Matlab, Scilab, Mathematica, C#, C++, assembler, Forth, Java, and Fortran are implementation details. Ignore them at first. If you don't want to...

Matlab, Scilab, Mathematica, C#, C++, assembler, Forth, Java, and Fortran are implementation details. Ignore them at first. If you don't want to use somebody else's library, start by learning exactly what the program needs to accomplish. If it were a hardware project, you would begin with a block diagram. Jerry


Pi approximation games

Started by Tim Wescott in comp.dsp7 years ago 137 replies

Instead of doing productive work, I just spent a few enjoyable minutes with Scilab finding approximations to pi of the form m/n. Because I'm...

Instead of doing productive work, I just spent a few enjoyable minutes with Scilab finding approximations to pi of the form m/n. Because I'm posting to a couple of nerd groups, I can be confident that most of you probably know 22/7 off the tops of your heads. What interested me is how spotty things are -- after 22/7, the error drops for a bit until you get down to 355/113 (which, if yo...


Large FFT --- NOT radix-2

Started by Richard Owlett in comp.dsp15 years ago 25 replies

Any pointers to doing non-radix 2 FFT's. Specifically I wish to do 44100 pt FFT's on 16 bit data. Simplicity of coding OUTWEIGHS speed! [...

Any pointers to doing non-radix 2 FFT's. Specifically I wish to do 44100 pt FFT's on 16 bit data. Simplicity of coding OUTWEIGHS speed! [ Scilab is slow but adequate ]


MATLAB clones?

Started by Airy R. Bean in comp.dsp15 years ago 4 replies

For those of us not blessed with free access to Matlab based upon job or Alma Mater, what is a good choice in the clones? www.scilab.org is...

For those of us not blessed with free access to Matlab based upon job or Alma Mater, what is a good choice in the clones? www.scilab.org is given as a good one, but I cannot get to it from here in the evenings, for some reason (although tracert get to it in 35 msecs)


testing dft filterbank implementation

Started by Anonymous in comp.dsp12 years ago

i've written a dft filterbank (analysis) using c++ and wondering how to test it. if any one know an implementation using scilab or c/c++ please...

i've written a dft filterbank (analysis) using c++ and wondering how to test it. if any one know an implementation using scilab or c/c++ please let me know.


DSP Development Tools On The Web

Started by Tim Wescott in comp.dsp12 years ago

I'm working on yet another article, and as usual I'm asking the community for help. This is a departure for me in that I'm planning on...

I'm working on yet another article, and as usual I'm asking the community for help. This is a departure for me in that I'm planning on reviewing web-based resources for DSP optimization and profiling -- yet I'm not a big one for using anything other than first principals plus a math package like SciLab. I know I've seen suggestions for filter packages and other things fly by -- what ...


SciPy and DSP

Started by Giulio Petrucci in comp.dsp11 years ago 15 replies

Hi there, I'm trying different alternatives in order to choose a software for scientific calculation, expecially for the resulution of...

Hi there, I'm trying different alternatives in order to choose a software for scientific calculation, expecially for the resulution of (simple) DSP problems. Currently I'm using Scilab. Anyway I'd like to learn to use SciPy too bt I wasn't able to find any useful "for-dummies" documentation about DSP in SciPy. Do you have any interesting link? Thanks in advance! Ciao, Giulio ...


Plotting log magnitude of FFT of a rectangular pulse

Started by Richard Owlett in comp.dsp15 years ago 2 replies

I was trying to reproduce something similar to Figure 3-25b in Rick's book (second edition) in Scilab. My code...

I was trying to reproduce something similar to Figure 3-25b in Rick's book (second edition) in Scilab. My code is a(1:899)=1; a(900:1000)=0; plot2d( [1:1000], abs(fft(a,-1)), logflag="nl") What could be wrong ; < ( I tried to attach a jpg of the result, but comp.dsp refused it )


peak continuation algorithm

Started by juli...@yahoo.com in comp.dsp12 years ago 8 replies

Hi, For my final university project, i'm working on audio pitch shifting using the FxEngine framework from smprocess and scilab. To succeed...

Hi, For my final university project, i'm working on audio pitch shifting using the FxEngine framework from smprocess and scilab. To succeed in my project, I'm looking for papers, links about the peak continuation algorithm. Thanks for your help, julius


SciLab

Started by Dirk Bruere at NeoPax in comp.dsp12 years ago 3 replies

Quick Q Can this be used as a replacement for MatLab in VisualAudio filter development? -- Dirk http://www.onetribe.me.uk - The UK's...

Quick Q Can this be used as a replacement for MatLab in VisualAudio filter development? -- Dirk http://www.onetribe.me.uk - The UK's only occult talk show Presented by Dirk Bruere and Marc Power on ResonanceFM 104.4 http://www.resonancefm.com


Vizualize speech

Started by Richard Owlett in comp.dsp16 years ago 2 replies

I've installed Scilab, I act on advice eventually ;} My goal is to get a feel for what speech "looks like" ; personal education [ If successful...

I've installed Scilab, I act on advice eventually ;} My goal is to get a feel for what speech "looks like" ; personal education [ If successful I may rediscover fire and reinvent a few wheels. ] I have a large speech file [ from CD of some one reading ]. I have experimented enough to plot a "power" spectra of a segment of the recording. {stacksize chosen to load input file with room to sp...


A 3D alternative to spectrogram

Started by Richard Owlett in comp.dsp11 years ago

There have occasionally been threads here on visual presentation of displaying time sequential spectra. Spectrograms (gray scale or color) are...

There have occasionally been threads here on visual presentation of displaying time sequential spectra. Spectrograms (gray scale or color) are very popular. [e.g. http://en.wikipedia.org/wiki/Image:Praat-spectrogram-tatata.png ] I sat for many hours in front of RF spectrum analyzers, so I'm not oriented to that format. Scilab is free and has reasonable graphics, so I wrote my own. ...


HELP - submatrix incorrectly defined ;(

Started by Richard Owlett in comp.dsp13 years ago 1 reply

I originally posted this to the Scilab group assuming i just had a syntax error. While waiting for a response, I started wondering if I was...

I originally posted this to the Scilab group assuming i just had a syntax error. While waiting for a response, I started wondering if I was also headed for some DSP specific pitfalls. Comments welcome. *********** I know I'm making a basic (no pun intended) error. But i just can not find the proper syntax. My code is: sheets = readxls('E:\parasitic.xls') s1=sheets(1); ...


[OT??] {32 vs 64 bit} &/or {single vs multi core} ???

Started by Richard Owlett in comp.dsp7 years ago 6 replies

{also posted to a Linux group} In the "real world", is there a difference for an average/typical user. I'm contemplating the move from...

{also posted to a Linux group} In the "real world", is there a difference for an average/typical user. I'm contemplating the move from Windows to Linux. Coward that I am, I'm considering separate hardware as testbed. I spend most of my time in text editing and web surfing - doubt any advantage there. My other interest include Scilab, Scioslab, and gnuplot. I would run and display disp...


QR Decomposition with a twist

Started by Tim Wescott in comp.dsp9 years ago 7 replies

I'm working on a nav problem, and I'm looking for some computational efficiencies. I'm carrying position and velocity information in...

I'm working on a nav problem, and I'm looking for some computational efficiencies. I'm carrying position and velocity information in earth-centered, earth- fixed coordinates, and I have a need to do some post-processing in north- east-down coordinates. I'm using Scilab's QR decomposition at the moment. I can do this decomposition on a 3 x 2 matrix with the position vector and the eart...


about IIR Filter implementation...

Started by zeugnim in comp.dsp12 years ago 2 replies

hi, This is my first filter implementation and is made in Scilab, also the design of the 3ord Chebyshev Type I IIR Filter (with the iir...

hi, This is my first filter implementation and is made in Scilab, also the design of the 3ord Chebyshev Type I IIR Filter (with the iir function). I actually have 3 filters, so i can use them as an equalizer for an audio application. I´m using Direct Form I Realization. Since I have to implement this on a 24bit Fixed-Point DSP I had to scale my coefficients by a factor of 256 (same as shifting...