Respondida
looking for an efficient way to activate all fprintf in the function
Probably not what you are looking for, but a quick way may be to just do a search and replace all (i.e., search for: "fprintf" r...

más de 11 años hace | 0

Respondida
How to manipulate Plot Legend to show markers and colours seperatly?
It can be done... you will have to do some finagling, but it can be done. Here is an example where we have 2 different datasets ...

más de 11 años hace | 8

Respondida
How to check if a file of certain type exists in folder?
You could try doing something like: dir_struct = dir( fullfile(your_path,'*pdf') ); if numel(dir_struct) == 0 % then ...

más de 11 años hace | 0

Respondida
Plotting lognormal data on this type of graph?
The key ended up being *norminv*. Here is an example output of the program I made (see below for *probit* function): >> pro...

más de 11 años hace | 0

| aceptada

Pregunta

Plotting lognormal data on this type of graph?
I would like to plot data on a graph similar to that illustrated in the figure below (except it is upside-down from my conventio...

más de 11 años hace | 2 respuestas | 0

2

respuestas

Respondida
I have a rather large matrix. The data was sampled at 100 Hz. I want to the data to look like it was sampled at 5 Hz
Use *resample* - This is an example of why you may not want to take every Nth amplitude: <<https://lh5.googleusercontent.com/...

más de 11 años hace | 0

Respondida
use FFT in matlab and get phase plot
Here are the frequencies associated with the output from FFT: Nt = % Number of time samples Fs = ...

más de 11 años hace | 0

| aceptada

Respondida
Area of a Spectrum
The area under your curve should just be: N = numel(x); dt = 1/fs; df = fs/N; y = fft(x)*dt; area_y = sum(abs(y))*d...

más de 11 años hace | 0

| aceptada

Respondida
How to get back complete signal after doing IFFT
Can you provide an example of how you are performing the fft? Something like: a = your_dataset_in_the_time_domain; size_a ...

más de 11 años hace | 0

Respondida
How to run 3D FFT?
Have you checked out *fftn*?

más de 11 años hace | 0

Respondida
ifft and fft problem
Did you mean to use "fs_s" instead of "f_s" here: h1_s_hat = abs(fs_s.*ifft(ifftshift(h1_s_FT))); I guess that's why you...

más de 11 años hace | 0

| aceptada

Respondida
[DISCONTINUED] MATLAB Answers Wish-list #2 (and bug reports)
I kind of wish that when we scrolled through the answers to questions (especially when there are many "answers" like this one), ...

más de 11 años hace | 0

Respondida
Is there a built-in function that determines whether X/Y coordinates give valid polygon?
My attempt: % Assume polygon is valid answer = 1; % Set tolerance tol = 0.001; % Random set...

casi 12 años hace | 0

Pregunta

Is there a built-in function that determines whether X/Y coordinates give valid polygon?
If I have a vector of X-coordinates and a vector of Y-coordinates, is there a function that determines whether a valid polygon i...

casi 12 años hace | 3 respuestas | 1

3

respuestas

Respondida
How do you centre your plot at '0' on the X-axis after performing a Fourier transform?
*fftshift* might be what you are looking for. Does this example help? dt = 0.1; % Fs = 1/dt; N = 16; t = (0:N-1)*dt; ...

casi 12 años hace | 0

Respondida
how is a Shock response spectrum estimated
You might take a look at this FEX submission: <http://www.mathworks.com/matlabcentral/fileexchange/7398-shock-response-spectr...

casi 12 años hace | 0

| aceptada

Respondida
2D spectral energy density using fft2 - energy in spatial domain unequal to that in wavenumber domain
*[EDIT 7/06]* M=8;N=16; N=8;M=16; dx=0.1;dy=0.2; f = randn(M,N); % Energy in time domain energy_f = sum(sum(f.^2...

casi 12 años hace | 1

| aceptada

Respondida
How can I choose a subset of k points the farthest apart?
Added a few more tests (including your latest) and added your data (instead of just random dataset), which may be of interest. R...

casi 12 años hace | 0

Respondida
Simple question for GUI
Also wanted to add a good resource for those who want to learn how to program a variety of things in Matlab GUIs: <http://www...

casi 12 años hace | 0

| aceptada

Respondida
Bandpass Filter By Using Butter
Okan - Ambient noise is like random noise... the frequency domain response (if you were to plot the abs of the frequency domain ...

casi 12 años hace | 0

Respondida
How can I choose a subset of k points the farthest apart?
Went with a "simple" way - tried to maximize the sum of the distances between each point in the sub-set of "n" below (similar to...

casi 12 años hace | 0

Respondida
Legend Problem
Matlab is only doing what you tell it to. One of the places where you define your figure, you have your "hold on" just after you...

casi 12 años hace | 0

Respondida
[DISCONTINUED] MATLAB Answers Wish-list #2 (and bug reports)
Has someone already addressed the change from having our most recent answers listed first to (now) where our oldest answers are ...

casi 12 años hace | 1

Respondida
FFT
Your first amplitude represents 0 frequency. When your data has 0 mean, your first amplitude should also be 0.

casi 12 años hace | 0

Respondida
derivative using FFT properties
Based on the website below: <http://www.cl.cam.ac.uk/teaching/2000/ContMaths/JGD-notes/node11.html> I believe you would do...

casi 12 años hace | 0

| aceptada

Respondida
cycles/pixel to cycels/degree
See this link: <http://www.cogs.susx.ac.uk/courses/acv/matlab_demos/fft_image_demo.html> About half way down: F = fft...

casi 12 años hace | 0

Respondida
FFT of an image
See my answer here for a coded up description of what the 2D Fourier transform does using a random 2D image as an example (shoul...

casi 12 años hace | 1

| aceptada

Respondida
why real part of fft (exp(at)) is negative in some parts in contrary to analytical calculation of fft(exp(at))?
Try plotting the *abs* result from FFT. Basically, you will not get a purely real, all positive frequency spectrum unless your t...

casi 12 años hace | 0

Respondida
Area of a triangle
How about *polyarea*? >> x = [0, 0, 4]; >> y = [0, 3, 0]; >> area1 = polyarea(x,y) area1 = 6 >> area2 =...

casi 12 años hace | 2

| aceptada

Respondida
fft2: Frequency and wavenumber
Take a look at my post here for an idea of what is output from FFT2: <http://www.mathworks.com/matlabcentral/answers/24965-ff...

casi 12 años hace | 0

| aceptada