## Forums Search for: Scilab

## [OT?] -- Unambiguous term for "graph"

inI haven't had any math in over 40 years. "graph" has always meant plotting Y as function of x. I'm going to be using "graph" to at least...

I haven't had any math in over 40 years. "graph" has always meant plotting Y as function of x. I'm going to be using "graph" to at least three distinct *audiences* 1. Scilab news group when discussing Metanet This should cause no problem as using term Metanet sets context. 2. An engineering newsgroup whose normal use would of use re plotting a function, but would also b...

## Which Scilab curve fitting approach is most applicable.

inUltimate Goal: Get a feel for pitfalls associated with changing sample rate. Immediate Goal: Create an artificial test signal which I...

Ultimate Goal: Get a feel for pitfalls associated with changing sample rate. Immediate Goal: Create an artificial test signal which I intuitively understand. Starting point: Audio CD of text being read. It was originally recorded for cassette tape distribution circa 1974. Identical Material later distributed on CD. Assume from looking at FFT that original was likely low pass limited a...

## Vector quantisation for clustering

inI am hoping to identify clusters within a set of vectors using vector quantisation. I have only just started looking into vector quantisation...

I am hoping to identify clusters within a set of vectors using vector quantisation. I have only just started looking into vector quantisation so I'd like to ask a couple of questions. I'm implementing the LBG algorithm in Scilab, and it has just occurred to me - what if I want to identify five clusters - or three? The LGB seems to work only for 2^x number of clusters am I right? Perhaps this...

## Confused by gross differences between spectra of similar signals

inIn another thread it was suggested I use Scilab's smooth() function to increase my effective sample rate (sample code was given). I applied...

In another thread it was suggested I use Scilab's smooth() function to increase my effective sample rate (sample code was given). I applied the code to my problem and got the desired effect. I performed an FFT on the smoothed data and did not get a spectrum of the expected character. I could couldn't find a programming error. I've created the test case below. ptd = 0:30; ptd = [p...

## How much trouble can a NEWBIE get into doing SIMPLISTIC filter in frequency domain

in[ has background related to [NEWBIE question] How do I filter a digitized signal ] I have a real [only] input {voice in .WAV format) I...

[ has background related to [NEWBIE question] How do I filter a digitized signal ] I have a real [only] input {voice in .WAV format) I do a Scilab fft on it. I multiply the resulting frequency domain by a "filter function" *CASE 1* Value of filter is either 1 or zero depending on frequency The filter will have same value over intervals of at least 1/12 octave There will be mult...

## Newbie needs help optimizing quantized FIR LPF coefficients

inHi, I want to implement a speed-critical FIR LPF (order about 50-60) in a 16bit MCU (MSP430), but it's MAC accumulator is only 32 bits, so...

Hi, I want to implement a speed-critical FIR LPF (order about 50-60) in a 16bit MCU (MSP430), but it's MAC accumulator is only 32 bits, so it could overflow with bad results if I don't scale down the coefficients so the peak value is about 7000 (decimal). I've installed SciLab hoping to find a way to optimize the coefficients, but I can't find anything in Signals that directly relates. Is ...

## Power Chords

inSo, I'm trying to generate power chords in Scilab, and I'm just hearing ugly buzzing sounds. The closest I come to real power chords is if I...

So, I'm trying to generate power chords in Scilab, and I'm just hearing ugly buzzing sounds. The closest I come to real power chords is if I allow things to distort heavily. f = 500; // Hz t = (0:22050)/22050; y = 0.5 * (sin(2 * %pi * f * t) + sin(2 * %pi * 1.5 * f * t)); playsnd(y); Clues for the clueless? -- Tim Wescott Wescott Design Services http://www.wescottdesig...

## custom IIR filter

inI'm designing a custom IIR filter that has a specific transfer function (not standard chev or any other filter). I have it modeled in scilab...

I'm designing a custom IIR filter that has a specific transfer function (not standard chev or any other filter). I have it modeled in scilab and have a linear system which I can plot. Were I'm lost is how to take the linear system (16th order system) and break it down into 4 bi-quad sections. My first thoughts were I would just pump it through the pfss (partial fraction decomposition) funct...

## lms-dfe implementation

Hi experts, I am a usual ng lurker but now it is time to make my first question, as I am stuck on a lms-dfe implementation issue. I use the...

Hi experts, I am a usual ng lurker but now it is time to make my first question, as I am stuck on a lms-dfe implementation issue. I use the textbook equations (implemented in Scilab) to estimate, via LMS, the filters coefficients. I do a classical LMS to estimate the fwd filter coeffs, still being in training mode, so I have: d=known desired signal (training sequence) X=input to the eq...

## [NEWBIE question] How do I filter a digitized signal

inI'm starting with chapters 5 and 6 of the 2nd edition of Rick's _Understanding Digital Signal Processing_ . I have no problem with...

I'm starting with chapters 5 and 6 of the 2nd edition of Rick's _Understanding Digital Signal Processing_ . I have no problem with explanations using summation operator ( CAP SIGMA ). How do I filter a digitized signal? I *think* I'm looking for a matrix representation. I'm using Scilab. I have an extremely large linear vector as input. How do I apply filter? Size input vector > > >

## Spectrum analysis (FFT) of partial waves / scilab

inHi, Could someone recommend the best spectrum analysis software package - or method - for dealing with signals having only partial waves? I've...

Hi, Could someone recommend the best spectrum analysis software package - or method - for dealing with signals having only partial waves? I've been using SigView's FFT function on such signals, but the results are unexpected. I've tried applying filters/windows, varying the sample rate, and other things, but to no avail... If I pass in sustained signals comprising multiple wavelengths, e.g. ...

## Vocal glissandro as swept frequency source

inI've become interested in viewing and describing formants. I've written a Scilab program that is a cross between a traditional spectrogram and a...

I've become interested in viewing and describing formants. I've written a Scilab program that is a cross between a traditional spectrogram and a waterfall display. I was looking on the web for a solo vocal glissandro to use as a test source. The object of the test is twofold. Does my program give useful display? Initial test looks good. Second can I identify formants from it? Anyone ...

## what filter to use in Scilab for I/Q demodulation of a signal

inI'm trying to find the imaginary and real parts (I and Q) of a bandpass signal (i'll call this bandpass signal "s"). To find the imaginary...

I'm trying to find the imaginary and real parts (I and Q) of a bandpass signal (i'll call this bandpass signal "s"). To find the imaginary part, i first multiply the bandpass signal (s) by sin(2*pi*t*fc), where t is the time in seconds and fc is the center frequency of the signal's energy distribution. s * sin(2*pi*t*fc) = m Next, i need to low pass filter this signal (m). This filtering...

## Good old Hilbert Transform question

inHello everyone, just a little question about the good old Hilbert Transform. - Goal: obtain analytic signal (a(n)+j?(n)) from an in-phase...

Hello everyone, just a little question about the good old Hilbert Transform. - Goal: obtain analytic signal (a(n)+j?(n)) from an in-phase signal (a(n)); - Tool: Blackfin BF537. I get a sampled signal, and i compute it's hilbert transform using a FIR filter with coefficients obtained using Matlab/Scilab's "Hilb" function. -Problem: I have to create the analytic signal in a numeric fashion.....

## Good software list to enhance productivity of DSP designers.

inHello All, So far we had discussions on listing good books on DSP and also some free books available online. Let us start this...

Hello All, So far we had discussions on listing good books on DSP and also some free books available online. Let us start this discussion thread, on which free softwares DSP designers use to enhance their productivity? Like for example octave/scilab/rlab or others. Please also mention that if the software runs only on windows /linux or both, and some useful features of ...

## Generate noise with specific crest factor

inHi all, It's been a couple of years since I last visited comp.dsp. But now I finally have a dsp related question :) I need to generate noise...

Hi all, It's been a couple of years since I last visited comp.dsp. But now I finally have a dsp related question :) I need to generate noise with a specific crest factor, so I tested in SciLab with: 1. Generate a vector of uniformly distributed random numbers (noise if you will) in the range [-pi/2,+pi/2] 2. Feed that into sin(...) and get a vector with range [-1,+1] Seems to work pretty...

## Is octave good to do image processing?

inHello All, I found octave to be good for signal processing applications. But is octave good for doing image processing too? The...

Hello All, I found octave to be good for signal processing applications. But is octave good for doing image processing too? The reason why I am asking this, is sometimes back I was using scilab for image processing applications. when I ventured more in depth I found it to be dead slow for processing large amounts of data, and specially if there were any ...

## converting Matlab's

Hi, I'm trying 2 realize the function "butter" as iin matlab, using scilab. So instead of [a, b]=butter(ord,[int1* 2/Freq int2*2/Freq]); I...

Hi, I'm trying 2 realize the function "butter" as iin matlab, using scilab. So instead of [a, b]=butter(ord,[int1* 2/Freq int2*2/Freq]); I write the following: hz=iir(ord,'lp', 'butt', [int1/Freq int2/Freq], [0 0]); a=coeff(denom(hz));a=a($:-1:1); b=coeff(numer(hz));b=b($:-1:1); and I don't get the same results as in matlab. What do I do to get the same results? p.s. I'...

## Scilab, Laplace transform, root-locus and transient response

I created a web with problems and examples of transient response (steady-state error, response to ramp, response to step, response to impulse,...

I created a web with problems and examples of transient response (steady-state error, response to ramp, response to step, response to impulse, peak time, settling time, maximum overshoot, Routh's stability ),root-locus (damping ratio, undamped natural frecuency) and Laplace Transform http://cpbas.webcindario.com/eng/control/TransientResponse/index.php

## [VERY ot] WIKI page creation/editing _TEXT_ introduction

inIs there a *TEXT* based (rather than *hyper link*) intro/tutorial on creating and editing pages? Is that plain English? I've gotten...

Is there a *TEXT* based (rather than *hyper link*) intro/tutorial on creating and editing pages? Is that plain English? I've gotten *strange* replies to similarly phrased question. SEE: http://groups.google.com/groups?&as_ugroup=comp.soft-sys.math.scilab&as_usubject=wiki&as_uauthor s=owlett or http://groups.google.com/groups?&as_ugroup=24hoursupport.helpdesk&as_usubject=wiki&as_uauthors