Displaying 20 results from an estimated 3000 matches similar to: "waveform filtering"
2017 Nov 12
2
create waveform sawtooth
My tuneR sawtooth wave function generator is broken.
When I use the sine function, I get exactly what I expect: a sine wave whose frequency is defined by the freq parameter. In particular, higher frequencies have shorter wavelengths (more cycles per second means shorter waves). When I create a sawtooth wave, the opposite seems to occur: higher frequencies result in longer waves. But that?s not
2005 Aug 19
2
FFT, frequs, magnitudes, phases
Hi,
I'm in dire need of a fast fourier transformation for me stupid biologist,
i.e. I have a heartbeat signal and would like to decompose it into pure sin
waves, getting three vectors, one containing the frequencies of the sin
waves, one the magnitudes and one the phases (that's what I get from my data
acquisition software's FFT function).
I'd be very much obliged, if someone
2017 Nov 12
0
create waveform sawtooth
Ccing the maintainer if the tuneR package.
Looks to me like sawtooth (and square) don't behave as expected when using xunit="samples". Workaround is to use xunit="time" instead:
sawtooth(110,duration=1/100,samp.rate=sample_rate,xunit="time")
I looked at the code but found it to be opaque.
--
Sent from my phone. Please excuse my brevity.
On November 12, 2017
2005 Oct 19
2
Filter design in R?
Dr. Williams,
I ran across your inquiry on one of the R-help mailing lists regarding
digital filter design and implementation. I found no response to your
email in the archives and was wondering if you were able to find anything.
Thanks,
Israel
--
Israel Christie, Ph.D.
Email: ichristie at gmail.com
Phone: 865.766.0214
Mobile: 865.406.4615
2008 Oct 27
2
Stuck with FFT
Dear all,
Before I can get into serious Fourier analysis of Radon time-series I am
practising with 24hour and 24.8hour sinusoids to assist with my
interpretation of signals ittributed to tidal input to Radon time series.
I am stuck. I have tried researching this to no avail. I am awating a book
that should describe fourier transforms in detail and another one that
should discuss the R
2004 Jul 15
1
Spectrum Analyizer software
This was an interesting post from another list
I'm on. I think that with all of the echo
cancellation discussion happening, that someone
perhaps might be on the lookout for this type of
software, so this post was well-timed for
Asterisk uses. It is perhaps the case that those
of you working on volume/echo/etc stuff might
find this useful towards your goals.
JT
>To: [snip]
2007 Oct 10
1
average waveform over many cycles
I have 400 cycles of a noisy waveform. I would like to find the average
(over the 400 cycles) of one cycle. Please tell me to do it in R. Any
suggestions welcome!
Thanks very much for any help.
Bill
2009 Nov 28
2
fft and filtering puzzle
I am puzzled by a filtering problem using fft(). I don't blame R.
I have a waveform y consisting of the sum of 2 sinewaves having freqs f1 and f2.
I do s = fft() of y.
Remove s's spike at freq=f2
Do inverse fft on s.
The resulting waveform still has a lot of f2 in it! But the filtering
should have removed it all.
What is going on, and how to fix??
Thanks very much for any help.
Bill
2005 Feb 15
1
convolution of functions
Dear sir,
we would like to know if there exist any R package containing the
computational performance of the n-fold Stieljes' convolution of functions.
We look forward to hearing from you.
Thank you in advance.
____________________________________
M.Luz G?miz P?rez
Dpt. Estad?stica e Investigaci?n Operativa
Facultad de Ciencias
Universidad de Granada
Telf.: 958-243156
e-mail:
2008 May 27
5
MKL Patch
Alexander Chemeris wrote:
> Hi,
>
> On 5/27/08, Thorvald Natvig <thorvald at natvig.com> wrote:
>
>> And here's a patch for Intel Math Kernel Library. This allows commercial
>> users of Speex to use a high-speed FFT library that isn't GPL'd. (You do
>> need to pay for it though). This is 3 times faster than the default FFT in
>> speex, and
2004 Aug 10
3
Polycom IP 500 - MWI Not Working
Hello All,
I have Polycom IP 500 phones which I would like to have message waiting
indicators on. So far, I have my system running well but the problem I
am seeing is that MWI doesn't seem to tell my phone that it should
display a MWI state. The light does not show when you have message nor
is there any indicator on the text lines of a message waiting. The wiki
doesn't cover this
2006 Jun 10
2
R usage for log analysis
Hello,
Is there any software project that uses R to do log file analisys?
thanks
gabi
2003 May 31
4
faster mdct's
Hello Vorbis folks,
I'm one of the FFTW authors (www.fftw.org), and a few days ago I was
playing with our codelet generator for fun and modified it to spit out
hard-coded MDCTs of small sizes. The code (at
jdj.mit.edu/~stevenj/mdct_128nr.c) for 256 samples (128 outputs) seems to
be almost twice as fast as the Vorbis MDCT code for that size on my 2.2GHz
P-IV (gcc 3.2.2 and flags "-O1
2008 Jun 09
2
using spec.pgram
Hi everyone,
first of all, I would like to say that I am a newbie in R, so I apologize in
advance if my questions seem to be too easy for you.
Well, I'm looking for periodicity in histograms. I have histograms of
certain phenomenons and I'm asking whether a periodicity exists in these
data. So, I make a periodogram with the function spec.pgram. For instance,
if I have a histogram h, I
2005 Sep 08
2
Time Series Analysis: book?
There has been a few questions on the subject lately.
Is there any book on the subject, if possible with a computer processing flavor,
that you would highly recommend?
Many thanks in advance,
--
Jean-Luc
2003 Mar 11
3
fft help
Hi R-users:
I want to know if there is an easy way to obtain a Fourier Transform form
a vector or an array (just like fft does), but with a more density base.
I mean, if I have a vector of 512 of length, I want the Fourier
Transform to
be 1024, or 2048, etc, in length (de u domain). Or should I modify the
fft C code to do that?
If I want to modify the precision of the fft function, which
2006 Sep 11
3
Installation difficulty with "rimage"
Dear R people,
I am trying to install rimage using install.packages("rimage") but am
receiving the following errors despite having FFTW installed. I would
appreciate any help to get this fixed.
checking fftw.h usability... no
checking fftw.h presence... no
checking for fftw.h... no
configure: error: Sorry, can't find fftw header
ERROR: configuration failed for package
2009 Mar 05
2
Fast Fourier Transform w.r.t. CreditRisk+
Dear R Helpers,
Is there any literaure available (including R code) on Fast Fourier Transform being used in CreditRisk+? I need to learn how to apply the Fast Fourier Transform. I agree I am too vaue in my question and sincerely apologize for the same, but I am not able to understand as to where do I start for this particular assignment. I tried to search google for CRAN and Fast Fourier
2005 Feb 01
1
mdct.c optimization
I took function mdct_butterfly_8 and write out transformation matrix. Then I rewrote this matrix into sequence of additions and substractions (see attachement). As I suspected I got the same as in the original code but I swaped some rows to get little higher speed. I hope I'll do the same with 16 point butterfly function combined with 8 point butterflies in a month. Who still believe that this
2008 May 28
1
MKL Patch
On 5/28/08, Jean-Marc Valin <jean-marc.valin at usherbrooke.ca> wrote:
> > Yes, MKL is commercial software and you do need to pay for it, but
> > unlike FFTW it's not GPL. FFTW is useless for any closed-source program
> > that wishes to use Speex, so this is the non-GPL alternative.
>
> Considering that FFTW also sells licenses for non-GPL use, I tend to
>