Answered
how to do symbolic type negation ?
Accoding to the doc page for assume(), maybe assume(~in(x,'integer')) will do what you want? I couldn't test it because my ve...

5 years ago | 0

| accepted

Answered
How to Find out the port/signal name which is connected to a particular input in a block
Can be done in two steps: signals = get_param(block,'InputSignalNames'); signals{double(string(get_param(block,'Port')))} whe...

5 years ago | 0

| accepted

Answered
Plotting the absolute value.
plot(abs(Fx))

5 years ago | 0

| accepted

Answered
what are the name of the two components in simulink
The one at the top looks like Bus Selector The one at the bottom is Add You can always right click on a block and click Help t...

5 years ago | 0

Answered
CDF of log pearson
Not familiar with the disribution, but can offer the following about this code: % data Q=[23.81 33.98 62.01 140.45 184.91 ...

5 years ago | 0

| accepted

Question

Why Does int() of rectangularPulse Return NaN?
syms t real x(t) = rectangularPulse(0,1,t); int(x(t),t,0,5) int(x(t),t,0,inf) int(x(t),t,-10,10) int(x(t),t,-inf,inf) Any ...

5 years ago | 1 answer | 0

1

answer

Answered
To Get Correct FFT Result the length(x) must be An Integral Multiple of 100?
The desired plot will be obtained when N, the number of elements of t, is an integer multiple of the ratios Fs/Fn, where Fs is t...

5 years ago | 2

| accepted

Answered
How to vectorize this for loop
For starters, why use symsum at all? Doesn't sum() do exactly what is needed? for t = 1:12054 k = 0:(12054 - t); L(t)...

5 years ago | 1

| accepted

Answered
Bode Plot's Phase Margin Decimal Precision
If you just want the actual phase (and other) margin to more accuracy and don't care about the pop-up data tip, use doc allmarg...

5 years ago | 0

Answered
vector direction calculation in order to remove impact of magnitude
I think you want something like this: mag = sqrt(u.^2 + v.^2); newu = u./mag; newv = v./mag; % now use newu and newv as inpu...

5 years ago | 0

Answered
How to model and simulate large nonlinear coupled mechanical systems effectively?
I think steps 2 and 3 can be replaced with: doc odeToVectorField If not, post a simple example to illustrate the problem.

5 years ago | 0

Answered
Very small u control values in LQR initial response
For this dicussion, I'm going to just use x and u as the symbols for the state and control variables of the linearized model, in...

5 years ago | 0

| accepted

Question

Is There a Way to Find all Shadowed Functions on the matlabpath?
I'm dealing with a code base of m-files all in one folder and sub-folders. I'm worried that different sub-folders contain files...

5 years ago | 1 answer | 0

1

answer

Answered
How to solve intergal for analytical form of ambiguity function
I was not able to get Matlab to return a solution in the expected form of the answer. But we can show that Matlab's solution is ...

5 years ago | 0

| accepted

Answered
How to determine if a signal in Simulink is within upper and lower limit bounds over a specified number of samples?
I'm going to assume that the signal in question is already sampled. Here's one approach. There are others. Input the signal to...

5 years ago | 0

| accepted

Answered
How to define the order of states and inputs of a state space model in Model Linearizer
If using the linearize() function, the inputs and outputs will be in the order specified in the io argument. The state ordering...

5 years ago | 0

| accepted

Answered
Is there a better method to plot the inverse Laplace of a function?
The copy/paste approach shouldn't be needed. For many functions, fplot() usually does the trick: syms s t U(s)=1/(s+1); u(t)...

5 years ago | 1

| accepted

Answered
Why a function can't get itself in Simulink after two consecutive differentiation and two integration operations？
For the top (continuous) branch, keep in mind that the Derivative block is a numerical approximation and it's output will be ver...

5 years ago | 1

| accepted

Question

Should Behavior of sub2ind() be Different for Symbolic and Numeric Inputs?
maxrows = 1; r = 1; a = 1; c = 1; ii = false; D = zeros(3,3,maxrows) % D is a double D(sub2ind([3,3,maxrows],a(ii),a(ii),r(ii)...

5 years ago | 1 answer | 0

1

answer

Answered
Empty linear analysis workspace after linearising model
linsys1 isn't empty. It's a static gain of zero. Double click the Derivative block. If the Parameter ("Coefficient c ....") i...

5 years ago | 0

| accepted

Answered
Euler's method code
The code that is posted solves a differential equation of the form y'(x) = f(x,y), y(0) = y0 and compares it to the exact solu...

5 years ago | 0

Answered
Finding curve length of vector r(t)=<2t, t^2, 1/3t^3> Given0<=t<=1
It looks like the equation for "magnitude" is incorrect Why is magnitude the sqrt of the sum of the squares of each individual ...

5 years ago | 0

Answered
How to explicit a matlab equation by using the symbolic toolbox?
Looks like there are two solutions for V based on reasonable assumptions: syms rho V CD0 K W S T positive syms gamma real eqn...

5 years ago | 0

| accepted

Answered
diff function rearranges symbolic expression leading to non-vanishing terms
Why not just use collect() and coeffs() on the elements of dxdt? If the system is affine in u, then those should give the desir...

5 years ago | 1

| accepted

Answered
DC gain discrete-time transfer function error
I think the problem is just inaccuracy of the numerical computation of the freuqency response at very small frequencies. Keep i...

5 years ago | 0

| accepted

Answered
Roots of a polynomial with variables
Don't know the scope of the actual problems of interest, but for the two examples in the question: syms x y sol = solve(3*x*y ...

5 years ago | 0

Answered
Boundary Value Problem\ Symbolic solution
Need to use sym(pi) syms y(t) cond = [y(0)==0,y(1)==0]; X = dsolve(diff(y,t,2)+sym(pi)^2*y==0,cond)

5 years ago | 1

| accepted

Answered
Heun's method stiff ODE
Correct implementation of Heun's method, as I understand it, is given below and compare to the analytic solution and other equat...

5 years ago | 2

| accepted

Answered
How to solve a system of second order nonlinear differential equations with boundary conditions
I was not able to solve the problem for the boundary conditions specified at t=2. But I was able to get a resonable looking sol...

5 years ago | 0

Question

What is the Best Way to Deal with an Empty Line Object?
Suppose I have some data: x = 1:10; y = 1:10; Now I want to plot three lines based on three logical index vectors. i1 = x<=3;...

5 years ago | 2 answers | 0

2

answers