Answered

Different output from pwelch and my own implementation of welch

At first glance the blue line looks like the square of the purple line. Looking at your code confirms this, pwelch is calculati...

Different output from pwelch and my own implementation of welch

At first glance the blue line looks like the square of the purple line. Looking at your code confirms this, pwelch is calculati...

2 years ago | 0

Answered

Question about PSD calculation using FFT

The fft results in a spectra that includes positive and negative frequencies. Don't ask me to explain what a negative frequency...

Question about PSD calculation using FFT

The fft results in a spectra that includes positive and negative frequencies. Don't ask me to explain what a negative frequency...

3 years ago | 0

| accepted

Answered

How to compute fft of the rat's licking time?

There has to be good a joke there somewhere... So your data is a set of timestamps when rat licks? Is this coming from a pr...

How to compute fft of the rat's licking time?

There has to be good a joke there somewhere... So your data is a set of timestamps when rat licks? Is this coming from a pr...

3 years ago | 0

Answered

-6211 DDC_StorageCouldNotBeOpened

I am actually running into a very similar issue. I have some TDMS files that can be opened, some others (usually longer files) ...

-6211 DDC_StorageCouldNotBeOpened

I am actually running into a very similar issue. I have some TDMS files that can be opened, some others (usually longer files) ...

4 years ago | 0

Answered

Analyzing landsurface using FFT

If you have a data point every meter, then that is your "sampling rate", 1 sample/meter. Your fft will result in frequency bins...

Analyzing landsurface using FFT

If you have a data point every meter, then that is your "sampling rate", 1 sample/meter. Your fft will result in frequency bins...

4 years ago | 0

Answered

Create an empty array of size (MxN) for xlswrite.

If you are writing to excel then you probably want to use a cell array, Array = cell(2592,2);

Create an empty array of size (MxN) for xlswrite.

If you are writing to excel then you probably want to use a cell array, Array = cell(2592,2);

4 years ago | 0

Answered

How can I import an excel workbook's SHEET TITLE?

use the xlsfinfo function to read the names of all the sheets in an excel file.

How can I import an excel workbook's SHEET TITLE?

use the xlsfinfo function to read the names of all the sheets in an excel file.

4 years ago | 0

Answered

How to create a band pass filter

you discuss a bandpass filter but you are applying a lowpass filter... Aside from that, the order really depends on what type...

How to create a band pass filter

you discuss a bandpass filter but you are applying a lowpass filter... Aside from that, the order really depends on what type...

4 years ago | 0

| accepted

Answered

In regards to finding phase difference using matlab inbuilt cpsd function.

angle(Pxy) is the correct way to do this. The phase of the cross spectra is looking at the difference between the channels so t...

In regards to finding phase difference using matlab inbuilt cpsd function.

angle(Pxy) is the correct way to do this. The phase of the cross spectra is looking at the difference between the channels so t...

4 years ago | 0

Answered

Power Spectral Density Estimates Using FFT

There are different ways of looking at it but the PSD is often written as: (fft*conj(fft))/(bin_width*NFFT^2) (fft*conj(ff...

Power Spectral Density Estimates Using FFT

There are different ways of looking at it but the PSD is often written as: (fft*conj(fft))/(bin_width*NFFT^2) (fft*conj(ff...

4 years ago | 1

Answered

Power spectral density of gaussian white noise

The "density" in PSD means that the power is normalized to something, usually 1 Hz, but in this case it is the Nyquist frequewn...

Power spectral density of gaussian white noise

The "density" in PSD means that the power is normalized to something, usually 1 Hz, but in this case it is the Nyquist frequewn...

4 years ago | 0

Answered

RMS power in signal: time series vs frequency series. PSD/RMS definition?

Your equations are a little muddled, and there are three basic errors. # There is a factor of 2 on the your fft result, I ass...

RMS power in signal: time series vs frequency series. PSD/RMS definition?

Your equations are a little muddled, and there are three basic errors. # There is a factor of 2 on the your fft result, I ass...

4 years ago | 0

Answered

How to get 2nd minimun value from matrix?

It is a little cumbersome but for any array x, this should work: min(x(x~=min(x(:))))

How to get 2nd minimun value from matrix?

It is a little cumbersome but for any array x, this should work: min(x(x~=min(x(:))))

4 years ago | 1

Answered

Problem in opening HDF5 file

after to get hinfo, stop and see what is in that structure. It will list the group and dataset hiearchy.

Problem in opening HDF5 file

after to get hinfo, stop and see what is in that structure. It will list the group and dataset hiearchy.

4 years ago | 0

Answered

Problem in opening HDF5 file

what is returned by hinfo? do you have 2 groups with a data channel in the second group?

Problem in opening HDF5 file

what is returned by hinfo? do you have 2 groups with a data channel in the second group?

4 years ago | 0

Answered

How can I filter white noise to obtain signal with desired PSD?

If you randomize the phases you will end up with a Gaussian distribution because the magnitude at every point will be a random c...

How can I filter white noise to obtain signal with desired PSD?

If you randomize the phases you will end up with a Gaussian distribution because the magnitude at every point will be a random c...

4 years ago | 0

Answered

How can I filter white noise to obtain signal with desired PSD?

you are trying to generate a time history with a specified spectral content, such that a PSD from the output will match the init...

How can I filter white noise to obtain signal with desired PSD?

you are trying to generate a time history with a specified spectral content, such that a PSD from the output will match the init...

4 years ago | 0

Answered

initial phase angle calculation

You can't expect them to be zero degrees just because there is no signal defined there. With no content at those frequencies, ...

initial phase angle calculation

You can't expect them to be zero degrees just because there is no signal defined there. With no content at those frequencies, ...

4 years ago | 0

Answered

initial phase angle calculation

I ran your code it and seems to be working as-is. -30 and -90 deg at 10 and 50Hz

initial phase angle calculation

I ran your code it and seems to be working as-is. -30 and -90 deg at 10 and 50Hz

4 years ago | 0

| accepted

Answered

Calculate an Input Signal using tfestimate, FFT and IFFT

I recently went through a similar exercise and so I can provide some answers.. _1. Is it possible to calculate the Transfer ...

Calculate an Input Signal using tfestimate, FFT and IFFT

I recently went through a similar exercise and so I can provide some answers.. _1. Is it possible to calculate the Transfer ...

4 years ago | 1

Answered

Compress only selected variables when saving to .mat

I know this is old, but I have been doing some similar work recently since I could tell it was taking longer than it should to l...

Compress only selected variables when saving to .mat

I know this is old, but I have been doing some similar work recently since I could tell it was taking longer than it should to l...

4 years ago | 0

Answered

How does Vrms of raw noise signal compare to power spectral density?

The square root of the integral of the PSD will equal the rms amplitude of the original time history. The integral of the PSD i...

How does Vrms of raw noise signal compare to power spectral density?

The square root of the integral of the PSD will equal the rms amplitude of the original time history. The integral of the PSD i...

5 years ago | 0

Question

Enlarged windows text size wrecking havoc on my GUI.

I have fairly complex signal processing GUI that is used within my company and I had issue with one user and I finally figured o...

5 years ago | 0 answers | 0

Solved

Who Has the Most Change?

You have a matrix for which each row is a person and the columns represent the number of quarters, nickels, dimes, and pennies t...

5 years ago

Solved

Finding Perfect Squares

Given a vector of numbers, return true if one of the numbers is a square of one of the other numbers. Otherwise return false. E...

5 years ago

Solved

Find the sum of all the numbers of the input vector

Find the sum of all the numbers of the input vector x. Examples: Input x = [1 2 3 5] Output y is 11 Input x ...

5 years ago

Solved

Indexed Probability Table

This question was inspired by a Stack Overflow question forwarded to me by Matt Simoneau. Given a vector x, make an indexed pro...

5 years ago

Answered

Plot a line over spectrogram

I've done this before, I believe the trick is to set the Z-value for your line so that is always above the spectrogram.

Plot a line over spectrogram

I've done this before, I believe the trick is to set the Z-value for your line so that is always above the spectrogram.

5 years ago | 0

| accepted