Community Profile

# Birdman

1.093 total contributions since 2017

Someone who is interested in Mathematics, Control and Engineering. Also, music as a hobby.

View details...

Contributions in
View by

Question

Strange behavior of diff function with symbolic variables
Hello everyone, There is a strange behavior that I encountered while using diff function with symbolic variables, not functions...

3 días ago | 1 answer | 0

### 1

Assign different value of step response to a transfer function at different time intervals
You can do it with a Signal Builder. I attached the Simulink model. Take a look.

23 días ago | 0

how to plot constant gain with bode
To plot Bode of constant, define it as a transfer function but in the following way: Gs=tf(R1/(R1+R2),1); bode(Gs);

24 días ago | 0

| accepted

How to write time dependent exponential with simple Simulink blocks
Try this attached model.

24 días ago | 0

"solve " function returns inaccurate solutions
Try this: syms x assume(x,'real'); solx=vpasolve(x-sqrt(x+1)-sqrt(x-1)==0,x) or syms x assume(x,'real'); solx=vpa(solve(x...

alrededor de 1 mes ago | 0

matching from multiple arrays
One way: Result=double(ref & (ref==a{1} | ref==a{2} | ref==a{3}))

alrededor de 1 mes ago | 0

Just wondering how to I plot these functions into Matlab?
Try this: syms x(t) h(t) x(t)=piecewise(t>=-1 & t<=1,1,t<-1 | t>1,0) h(t)=rectangularPulse((t-1)/4) t=-5:0.01:5; ...

4 meses ago | 0

How to construct a vector from specific elements in a matrix
B=[A(1,2);A(2,3);A(3,1)]

5 meses ago | 1

| accepted

differentiation for a function
syms y(x) diff(diff(y,x)==x-y^2)

5 meses ago | 0

How to delay a boolean signal by an amount of time?
Simply, use a *Delay* block. See the attached pictures for details.

7 meses ago | 0

| accepted

I can I do logical indexing on a column
Is it possible for a value to be smaller than -8 and greater than 8 at the same time? Check your logical operator. You need _OR_...

7 meses ago | 0

| accepted

Of course it can be done. Check the attached files.

7 meses ago | 1

NEED HELP IN MATLAB GUI FOR FOLLOWING CODE
Check the attached zip file. In screenshot, you will see how to enter x and y vectors and you will see that you obtain the resul...

7 meses ago | 0

| accepted

Can I get the formula from the result value?
You may use *Curve Fitting Toolbox* for adapting formula(or function let's say) for your input and output values. There are seve...

7 meses ago | 0

| accepted

I have a row vector consisting of 200 engine speeds. I want to feed one value at a time into an alternator block. How do I do it?
Use *From Workspace* block. Define your data at your workspace, and also define a time vector. These two vectors should be nx1, ...

7 meses ago | 0

| accepted

Stuck with symbolic variables
You need to also convert your numerical array into *symbolic* so that things will be possible. For instance: c=sym(c) c(...

7 meses ago | 0

| accepted

function [CM KG]=STtosi(In,Ib) It is not working
Since you did not mention why the function is not working, it may have two reasons: - Firstly, you need to save your function...

9 meses ago | 0

| accepted

Why do I receive an error message about output arguments for my Embedded MATLAB Function in Simulink?
Simulink wants to know the initial value and size of your output at the very beginning of the simulation. Therefore, add D=0...

9 meses ago | 0

Summing the diagonal of a matrix "the other way"?
This can be done as follows: res=[sum(diag(fliplr(A),3)) sum(diag(fliplr(A),2)) sum(diag(fliplr(A),1)) sum(diag(fliplr(A)))]...

9 meses ago | 1

| accepted

Error states 'Subscript indices must either be real positive integers or logicals' when trying to complete this for loop?
You can not subscript *element zero* of an array. Change your for loop to for i = 1:numel(range) Ti_in(i) = Ti_in -((I...

9 meses ago | 0

can anybody help me with the error?
Make sure that _TrainFeature_ (I assume it is a function) is located in your current working directory.

9 meses ago | 0

How do I perform Partial differential equation by Simulink?
You can't. Only numerical derivatives with respect to time can be calculated in Simulink.

9 meses ago | 0

| accepted

What does 'y:' stand for in plot command?
It means a _dotted yellow line_. For that, you may check the documentation of *plot* command. That third input argument decides ...

9 meses ago | 0

| accepted

How to convert row to matrix with below format????
Something like this should work: A=[3 1 1 4]; Ans=zeros(max(size(A))); r=1:max(size(A)); c=A; idx=sub2ind(s...

9 meses ago | 1

How to plot signal continuously?
Consider the following approach: A=randi([1 5],1,120798); %this is demo data, you will use your own data instead of this T...

9 meses ago | 0

How to extract elements of a matrix coming as output from a simulink block?
See the attached example. I made necessary explanations on the Simulink model. Check the contents of the MATLAB Functions.

9 meses ago | 0

using find function and logical array
Because Z(Z==1) will produce 1 1 1 1 1 which is a new column vector generated from the initial line. ...

9 meses ago | 0

| accepted

When simulating the response to a specific input signal, the input data U must be a matrix with as many rows as samples in the time vector T, and as many columns as input channels.
Try the following code. By the way, I did not understand why you gave *zeros* as input, therefore I changed it with *ones* vecto...

9 meses ago | 0