Community Profile

# Paul

Last seen: Today 自 2011 起处于活动状态

All

#### Content Feed

Can the Symbolic Math Toolbox Be Used to Prove Matrix Identities?
With the following defintions syms s A = symmatrix('A',3); B = symmatrix('B',[3 1]); C = symmatrix('C',[1 3]); L = symmatri...

1 day 前 | 1 个回答 | 0

### 1

getLoopTransfer is giving the same open loop transfer functions for two different systems
Hi Janki, I'd have to go through the math on the two calls to getLoopTransfer to determine if that result makes sense. Offhand,...

2 days 前 | 1

| 已接受

using hasSymType(expression, 'constants') returns true when no constants
Hi Andrew, Both of those examples seem to be in accordance with doc hasSymType and children, except that children returns a cel...

3 days 前 | 0

| 已接受

Can't get symbolic numbers.
Hi Austin, Seems to work here as you expect. sym(1/5) sym(1/5,'r') But the preceeding results are based on the default sympr...

3 days 前 | 1

FFT is shifting my artificial signal?
Hi Zach, a) create the X vector with spacing based on the sampling frequency, Fs b) create the wave vector with sinusoids comp...

5 days 前 | 0

| 已接受

Assigning certain seed value to Simulink Uniform Random Number block in programmatic way
Hi JW, That looks like a typographical error in the doc (which is odd, I've always imagined stuff like that is generated automa...

7 days 前 | 0

| 已接受

Number of filter taps in Gaussian filter design
Hi Jay, The doc page for gaussdesign states "The number of symbols between the start and end of the impulse (span) and the num...

8 days 前 | 0

| 已接受

Inconsistency between the FFT results and the analytic spectrum of a Gaussian function
Hi Sherwin, fft assumes the input sequence starts at k = 0, so we have to apply ifftshift on the input to fft. fs = 10; t = -...

12 days 前 | 1

| 已接受

How to plug x^2+y^2 in to euler's Method
Hi Michael, Focusing only on the error message ... this line is the source of the error f(i) = x.^(2).*(i)+y.^(2).*(i); ...

12 days 前 | 0

Solving symbolic third order polynomial
Hi Axel, What is the source for the equations in red? Here is Matlab's solution: syms q(t) a0 a1 a2 a3 q0 q1 dq0 dq1 t0 t1; ...

16 days 前 | 0

How to identify transfer function of a motor with IODelay?
Hi Erik, Here's what I tried: Load the data load forum.mat Run the script so I can operate on the same variables. Take note ...

16 days 前 | 1

| 已接受

Solving symbolically for variables that are equal to several equations
Hmm. Don't know why solve doesn't find a solution, syms xi v r a mu spec_eng1 = [xi == (v^2)/2-mu/r, xi == -mu/(2*a)] solve(s...

19 days 前 | 0

I am trying to get my function to return two variables to the workspace. It is a very simple function. What am I doing wrong.
If you want both outputs returned, use ouput arguments on the call [m,n] = save_13(1,2) When you call a function without outpu...

19 days 前 | 0

Simulink - output of a block as an another block parameter
Hi Wiktor, Some Simulink blocks have parameters that can be specified either internally or externally, such as the Integrator b...

19 days 前 | 0

Hello, I want to use the LPC function to achieve AR pre-whitening, will the AR coefficient obtained by fftfilt filtering signal is a residual signal?
Hello Yx Y, Based only on reading the lpc example, it would seem that the call to fftfilt should be xest = fftfilt([0 -a(2:end...

20 days 前 | 0

Using Fourier Series write a MATLAB function to synthesize the wave-form in problem (2-19), Assume A = 4mV. Your function should take n ( # of harmonics ) and produce a plot
Hi Evan First, check your code that defines one period of v(t). It''s probably easier to define v(t) using piecewise syms t T...

20 days 前 | 0

Use of syms, piecewise & conv commands
Hi Ben, First you have to decide if you want to solve the problem for a closed form expression using symbolic tools, like syms ...

20 days 前 | 0

| 已接受

how to get the correct plot of function sin(N+1)*pi*x^2/sin(pi*x)^2 with different N
Hi Daniel, I think you are correct that the limit of y as x approaches any integer is (N+1)^2. However, all the compuations are...

22 days 前 | 0

Repeat array onto the same row
A=[1,2,3,4] horzcat(A,A) horzcat(A,A(1:floor(numel(A)/2))) % or use ceils depending on how you want to handle the case where ...

23 days 前 | 1

| 已接受

How to plot FFT?
Hi Sara, The frequency vector needs to be corrected. And for this data it's helpful to subtract out the mean before taking the...

23 days 前 | 0

| 已接受

Fourier analysis of an spwm signal
Hi Mosharof, Load the data load spwm_one_cycle.mat Plot the differences between time samples. We see that the data is not equ...

25 days 前 | 0

transform the cell 'string' containing strings into a single string
load string.mat who string string_new = join(horzcat(string{:})) Probably not a good idea to have a variable named string, w...

26 days 前 | 1

Hi Niusha Here is the first part of the code: Fs = 1e3; t = 0:0.001:1-0.001; x = cos(2*pi*100*t)+sin(2*pi*202.5*t); xdft = ...

26 days 前 | 1

| 已接受

calculate wrong or "/" work different
Hi pipor The ldivide, .\ and mldivide, \, which is what you're actually using here, for the scalar case are mathematically (tho...

29 days 前 | 0

| 已接受

How to get the eigenvalues of a transfer funciton matrix
Hi 宇航 杨, Considering that question 1 is about the "eigenvalues of a transfer function matrix", I would say that defining what t...

1 month 前 | 0

Why does frequency spectrum gets flipped in STFT compared to the one generated from FFT?
Using random data rng(100); Matrix = rand(1000,1); Compute the stft [s,f,t] = stft(Matrix,5000/3,Window=rectwin(32),OverlapL...

1 month 前 | 0

| 已接受

Stability margins for a cascaded system with getLoopTransfer functions
Hi Daam, To get the stability margins at 'e', I believe this is correct: Le = getLoopTransfer(CL,'e',-1); % open-loop function...

1 month 前 | 1

| 已接受

Fourier transform of an impulse response function
Hi Jason, syms t tau f real % SYSTEM I'd use heaviside, but piecewise works too. h = piecewise(t>=0, 0.01005*(exp(-t))*si...

1 month 前 | 0

I have 4 input channels (time series) and two output channels (time series) form test. I would like to calculate transfer function using tfestimate (MIMO).
Hi Dhiren, Have you tried the 'mimo' option of tfestimate (link to doc page) ?

1 month 前 | 0

Does Error Message Depend on Whether or Not Function is Executed Inside Try/Catch?
I put in a service request to Tech Support on this question. Their answer was that the error that's returned to the user does, o...

1 month 前 | 1

| 已接受