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# Questions tagged [magnitude]

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62 views

### Confusion understanding Fourier series line spectra?

I am reading book signals and systems Laboratory with MATLAB where I am studing chapter 5, Fourier series and i trying to understand magnitude spectrum and phase spectrum but i have certain confuisons ...
• 871
1 vote
45 views

### Scaling of FFT2 magnitude in image-processing

I got the following code: ...
• 157
62 views

58 views

### Draw the poles and zeros in the z plane for a system with poles at 0.45±j1.06 and zeros at 0.58±j2.06 Also plot the magnitude response of the system

Can you guys share 1 resource that solves similar type of this problem. This is not do my homework post. I just want a place which solves this type of problem. If you have pdf in book or sth, do share ...
32 views

### Stable and causal system

How many stable and causal systems with the same magnitude response are there? I know this relates to an all pass system for two rational transfer functions but am not sure about the specifics of this
1 vote
113 views

### Why do the DTFT and FFT give me completely different results for magnitude at a specific frequency?

I am trying to write a program to compute the magnitude and phase of a specific, non-integer frequency component (i.e. given a sampled finite signal of length $N$, I want to know the magnitude and ...
196 views

### Non-zero DFT components where zero is expected?

I am implementing DFT in Octave. Here's my code: ...
61 views

### Blackman window magnitude attenuation

I am trying to compute the fundamental phasor using sliding window DFT. I have employed a Blackman window in conjunction i.e $$\sum_{k=0}^{L_{DFT}-1}x(k) w(k) e^{-j2\pi k/N}$$ where $x(k)$ is the ...
• 15
160 views

### Moving average filter output magnitude in simulink

I was using the Moving average filter provided by simulink. I set the window length equal to 31 samples and i was using a fixed step solver with a step size of $\frac{1}{(50\times24)}$. I used a unit ...
• 15
151 views

### SMA, SVM and PSD python

I'm looking for python functions (package) to calculate SMA (signal magnitude area), SVM (signal vector magnitude) and PSD (Power Spectral Density). The goal is to extract features from an ...
• 1
10k views

### Calculate the magnitude and phase of a signal at a particular frequency in python

I have a signal for which I need to calculate the magnitude and phase at 200 Hz frequency only. I would like to use Fourier transform for it. I am very new to signal processing. And this is my first ...
• 153
1 vote
99 views

### Magnitude response of mirrored (with respect to unit circle) poles and zeros

I just want to check that my understanding about the following paragraph from Optical Filter Design and Analysis by Christi K. Madsen, Jian H. Zhao is correct: A filter’s magnitude response is equal ...
1 vote
279 views

### Squared magnitude of the Z-transform

I am basically new to the $z$-transform and there are some points regarding its square magnitude that I do not understand. Basically I do not understand how in slide 4 of PDF, they arrive at the ...
816 views

### How to convert magnitude to dB in matlab

I exported a diagram from FDTD simulation, and now I want to change the magnitude to dB, here is the exported codes: ...
1 vote
77 views

### Terminology for instantaneous phase of magnitude component of complex signal

In my field, we deal with data that are originally complex-valued. Typically, researchers convert their data from real + imaginary to magnitude + phase, and then discard the phase data (i.e., we ...
• 13
77 views

### Working with a sound's magnitude instead of amplitude

I'm working on a project, where we're recording sound with a piezo-disc which looks a little something like this: Now, unless we're doing something horribly horribly wrong, I've discovered that we're ...
• 111
420 views

### Impulse response from frequency response in Matlab

I am trying to design equalization filter and therefore I want to define my own amplitude and phase response and then to obtain the impulse response of the filter. I thought that the output of the ...
• 41
1 vote
158 views

### What does this paragraph mean?

I'm reading this paper about about an algorithm to measure image sharpness, and am confused by these sentences in the 6th paragraph: It is well known that the attenuation of high-frequency content ...
• 195
1 vote
77 views

### What is the "Energy" equivalent of the Magnitude Spectrum

I have a semantic issue regarding the discrete spectrum $X[k]$ of a time domain signal with limited length $x[n]$, so we're talking about the FFT. Now, when I what to compare the bandwidth and ...
1 vote
1k views

### How do the magnitude and phase spectrum of an imaginary function look like?

Say I have the function $$x(t)=j \operatorname{rect}(t)$$ Is the phase spectrum even or odd? I am confused whether the phase spectrum is an odd/even function of $\omega$ (angular frequency, Fourier ...
198 views

### Why is there a negative in front of the phase response equation for this complex exponential?

first time on here! I'm working through "Digital Signal Processing using MATLAB" by Vinay and Proakis. Good book. I am stuck on this example tho. Shouldn't the imaginary part in the denominator (...
• 61
2k views

### Understanding FFTs for simple Sin / Cos

this is my first question in this forum, and although I read several threads on this side and googled a lot I could not find the answer to my question (maybe it is too basic)? For anyone reading this ...
• 63
3k views

### Calculating the magnitude spectrum and phase spectrum

From a window function $x(t)=u(t+2)-u(t-2)$, we can get the Fourier Transform $X(j\omega)=\frac{2\sin(2\omega)}{\omega}$. Then, I want to calculate its magnitude spectrum and phase spectrum. The ...
• 23
84 views

### Relationship between DFT input sequence and magnitude

Assuming there is a sequence that could look like this: $$x[n] = \{1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0,1, 1, 0, 0, 1, 1, 0, 0,1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0\}$$ Using this sequence, I want to ...
• 113
52 views

### FFT frequency-magnitude not correct when a positive gain EQ point is applied

I have a measurement system, which applies a log sine sweep as stimulus to a DUT and records the return signal. I then extract the impulse response, and perform an FFT on this to examing phase and ...
• 149
378 views

### Correctly scaling FFT of different lengths

I have been looking at using two FFTs of different lengths and displaying the output magnitudes on the same graph (a shorter length window for the higher frequencies, and a longer one for lower ...
• 149
I have a filter, with coefficients given by $$W=\sin((2*\pi*2*F_f*k/F_s)/(2*\pi*2*F_f*k/F_s))*h[k]$$, where $F_f$ is the filter reference frequency, $k$ runs from $-N/2$ to $N/2$ ($N$ is the order ...