Question

FFT of a single sinusoid showing noise ?!

Hi, I have a signal which I am sampling so at least 10 wavelengths or 10 time periods can be plotted. It then works out how...

1 year ago | 2 answers | 0

Question

uitable - how to extract negative numbers (but there is also empty cells) from a ui table in GUIDE

Hi, I am having issues extracting data from a ui table in GUIDE. The ui table has empty cells and also negative numbers. I ne...

1 year ago | 1 answer | 0

Question

GUIDE - How to use variables that are calculated in Button 1, in Button 2?

I am finding it difficult to understand how this is done, I have read some posts and answers on it but I am even more confused w...

1 year ago | 1 answer | 0

Question

Intermodulation products (third order) from MATLAB and FFT are too low

Hi, The intermodulation products I get from an FFT are too low but they scale correctly against my wanted frequency signal po...

1 year ago | 5 answers | 0

Answered

Intermodulation products (third order) from MATLAB and FFT are too low

Hi, Its attached. * It contains the controls at the start. * Then it has the transfer curve data, AM-AM and AM-PM. *...

Intermodulation products (third order) from MATLAB and FFT are too low

Hi, Its attached. * It contains the controls at the start. * Then it has the transfer curve data, AM-AM and AM-PM. *...

1 year ago | 0

Question

Polyfit with odd powers only?

Hi, I am trying to get a polyfit with only odd powers - so polyfit will not work because it has odd and even. I do not ha...

1 year ago | 2 answers | 0

Answered

Incorrect phase from fourier transform

Hi David, Thanks. Answers accepted. I've rewritten my third order intercept code a few times and this is part of it, reconstruct...

Incorrect phase from fourier transform

Hi David, Thanks. Answers accepted. I've rewritten my third order intercept code a few times and this is part of it, reconstruct...

1 year ago | 0

Question

Incorrect phase from fourier transform

Hi, * I make a few sinusoids of different frequencies with different phase offsets. * Add them to make a waveform * Fast F...

1 year ago | 2 answers | 0

Question

Phase angle is producing an error

Hi, I am getting a phase error on my waveform it is not quite reaching +pi or -pi in some cases(not everytime which I find stra...

2 years ago | 0 answers | 0

Question

Place polyfit values in a matrix using a loop

Hi I want to capture all the values from the polyfit function in a matrix when it is in a loop. for a=1:length(x) te...

2 years ago | 1 answer | 0

Question

No Second Order Harmonics in FFT

Hi, I have a script that generates a waveform (sum of sinusoids) and puts it through an AM-AM transfer curve (the input ampli...

2 years ago | 0 answers | 0

Question

How to represent waveform (sum of sinusoids) in complex notation

Hi, I have a sum sinusoids to make a waveform, each sinusoid has a different phase attached to it. clear f = ...

2 years ago | 1 answer | 0

Question

Plot a circle and a vector moving around it

Hi Draw a circle, then plot multiple vectors from the origin to the outline of the circle angle = 0:0.05:2*pi x ...

2 years ago | 2 answers | 0

Answered

Find elements from A in B and get the index of found element in B

I am interested in what Jo says, but I don't think that's the issue? I have tried what others have written above and it does not...

Find elements from A in B and get the index of found element in B

I am interested in what Jo says, but I don't think that's the issue? I have tried what others have written above and it does not...

2 years ago | 0

Question

Find elements from A in B and get the index of found element in B

Hi I have two arrays, A and B, A has 12,000 elements and B has 260,000 elements. I need to find every instance when an ele...

2 years ago | 5 answers | 0

Question

Adding Random phase causes fft anomalies?

Hi If I add random_phase to my waveforms then the fft goes skewy - basically it breaks down and is not producing what it shou...

2 years ago | 2 answers | 0

Question

fft working but end time of waveform distorting result

Hi, I am having a problem that my amplitudes are being affected when I change the end time that my waveform is sampled for. ...

2 years ago | 0 answers | 0

Question

Plotting a Surf of my waveform

Hi, my waveform is sampling = 1 / (1*10^6); t = 0: sampling :0.05 ; %Sample Rate f = (30 : 1 : 35)* (10^3); %Freque...

2 years ago | 1 answer | 0

Question

GUIDE - add windowed tabs manually or in using this tool?

Hi, I have figure that is output that I made with GUI, it has push buttons, tables, plots etc.... but now I want to have mult...

2 years ago | 0 answers | 0

Question

Tricky frequency spacing loop

I have a tricky loop, well I think its quite tricky... maybe its not for you * I have 1000 Hz of bandwidth. * I need to p...

2 years ago | 0 answers | 0

Answered

Memory leak from waveform plotting at high frequency

No idea what you mean by that. It crashes withn range above about 1Khz for example 1Ghz to 1.1Gz. I just want to be able to p...

Memory leak from waveform plotting at high frequency

No idea what you mean by that. It crashes withn range above about 1Khz for example 1Ghz to 1.1Gz. I just want to be able to p...

2 years ago | 0

Question

Memory leak from waveform plotting at high frequency

Hi I'm having problems with 16gb of RAM on my computer being taken up calculating the below. I know its because of t and ...

2 years ago | 3 answers | 0

Question

Combine a waveform from a set of sine waves which are linearly increasing in frequency

Hi, I generate and plot multiple waveforms which have increasing frequency. I want to combine them at each time interval of t...

2 years ago | 1 answer | 0

Question

String or Number to a time format

I have the following stored in an array called timearray thats been imported form a csv file 22:30:26:718 The format is ...

2 years ago | 1 answer | 0

Question

Find and read a value in an excel spreadsheet

Hi, If I create two arrays in MATLAB that represent and store the column name and row names of a table, I want to then find t...

2 years ago | 1 answer | 0

Question

Array to table not working after forming matrix

altitude = [ 5 10 15 20 25 30 35 40 45 50 55 60 65 ]; flux_up = [ 35 55 80 110 125 130 140 150 155 175 225 275 325]; ...

2 years ago | 2 answers | 0

Answered

Peak analysis of spectrum

Hi, I have used this but I need to insert a section of code that will be another filter for selection of peaks. The extra selec...

Peak analysis of spectrum

Hi, I have used this but I need to insert a section of code that will be another filter for selection of peaks. The extra selec...

2 years ago | 0