Answered
MATLAB telling me there are no real values to my step response when there are
Hi Sophie, It looks like that message will come up when calling step with a tf input with complex coefficients h = tf(1,[1+1i,...

3 years ago | 0

Answered
How to Obtain State Space Model from Bode Plot Data
Hi Muhammad, Here is the first part of the code: T2 = readtable('E7i_CSV.csv'); ...

3 years ago | 1

| accepted

Answered
Getting an equation from a signal transfer function
Hi Sifiso, Here is an example that might be helpful. Generate an input signal inputAudio = sweeptone(6,0.1); Fs = 44.1e3; N...

3 years ago | 0

Answered
How to avoid defining variable value with simulink.
No, this can't be done in Simulink, nor in the Control System Toolbox. With G1(s), G2(s), and H(s) define as symfun objects, you...

3 years ago | 0

Answered
Why I am not getting sample time in the discrete transfer function block.
Hi Gokula, The Discrete Transfer Fcn block is one of the Blocks for Which [Setting] Sample Time Is Not Recommended. Instead, Si...

3 years ago | 0

Answered
The problem is to obtain the eigen einergies of the Schrodinger equation for an array of l = 0:1: 5 and del = linspace(0,1,N)
hbar = 1; mu = 1;e = 1;De = 1;re = 1;alp = 0.01;N = 100; l = 0; del = 0; L = l.*(l+1); r = linspace(1,1.2,N);dr = r(2)-r(1); ...

3 years ago | 0

Answered
How do we choose matrices in state feedback control?
Hi Luc, For lqr, the B matrix multiplies the control input. As I don't know what the variables mean in your problem, I can only...

3 years ago | 1

| accepted

Answered
Why am I getting this error "Conversion to logical from sym is not possible." in line 18?
syms x syms y %f(x,y) = input("Enter the function of f(x,y): "); f(x,y) = x^4 + y^4 -2*x^2 + 4*x*y - 2*y^2; df_dx = diff(f(x...

3 years ago | 0

| accepted

Answered
Reducing symbolic expressions with assumptions, but NOT simplify?
Hi Aroni, Consider the simple expression syms x f(x) = sin(x)/sqrt(1-cos(x)^2) Simplify simplify(f) If we assume that x is...

3 years ago | 0

| accepted

Answered
I got error with "error using plot, vectors must be the same length"
Hi Tran, Next time, please copy/paste your code into the Question, which makes it much easier for people to help. Original cod...

3 years ago | 0

Answered
Jumps in signal connections - simulink
Hi Tobias, From the Matlab window: Click Preferences in the Environment ribbon. Select Simulink in the preferences window. C...

3 years ago | 0

| accepted

Answered
I need to put this block diagram in MATLAB (not in Simulink) and I do not know how to do it
Hi Carlos, Recheck the definiton of s2. Once you have that taken care of, I suggest you proceed with connect.

3 years ago | 0

Answered
I don't know how to introduce the block (s+6) in simulink
Hi Carlos, One option would be to use block diagram manipulation. For example (there is at least one other approach): a) chang...

3 years ago | 0

| accepted

Answered
Valid Shape FFT Deconvolution
Hi Benjamin, Here's an approach for the 'valid' convolution. Problem parameters: x = 1:7; nx = numel(x); h = 1:3; nh = numel...

3 years ago | 0

| accepted

Answered
Simulink - Saving Base Workspace Variables
One option is to use the Model Workspace: "Each model is provided with its own workspace for storing variable values."

3 years ago | 1

Answered
Matrices size difference within for loop and unable to perform assignment of elements
Hi mcp0228, The loop variable iNepochs will be a scalar value, hence the LHS of the assignment is a column vector. for iN...

3 years ago | 0

Answered
Why is Symbolic Math Toolbox Giving Decimal Answers?
Check your sympref The defaults are sympref Resulting in [sym(pi) sym(sqrt(3))] But, if you change this pref sympref('Floa...

3 years ago | 0

| accepted

Answered
Change content of Simulink Matlab Function block through console
Use MATLABFunctionConfiguration and modify the FunctionScript property.

3 years ago | 0

Question

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...

3 years ago | 1 answer | 0

1

answer

Answered
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,...

3 years ago | 1

| accepted

Answered
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 years ago | 0

| accepted

Answered
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 years ago | 1

Answered
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...

3 years ago | 0

| accepted

Answered
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...

3 years ago | 0

| accepted

Answered
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...

3 years ago | 0

| accepted

Answered
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 = -...

3 years ago | 1

| accepted

Answered
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); ...

3 years ago | 0

Answered
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; ...

3 years ago | 0

Answered
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 ...

3 years ago | 1

| accepted

Answered
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...

3 years ago | 0