Community Profile # Fabio Freschi

### Politecnico di Torino

Last seen: 8 days ago Active since 2014

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Population growth in 7 years
Below you can find the output of the following code % rate r = 0.0063; % years t = 7; % initial population a = 5e6; t =...

1 month ago | 1

Question

Problem with Simscape variable visibility
Hi all, I have created a simulink model of a circuit using simscape electrical elements. I have also created two callbacks, Ini...

6 months ago | 1 answer | 0

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how to find parallel of resistors
Maybe it's too late for the OP, but for the records, I usually use an anonymous function with multiple inputs % ananymous paral...

8 months ago | 0

Nonlinear equation numerical solution
% params C = 1.2; D = 9420; E = -2.0; B = 0.1973; y0 =...

1 year ago | 0

Plotting a taylor series function of x^(1/3) centred at x=1728
One option is to use the built-in taylor function in symbolic math toolbox. If you want to use your strategy, there are some is...

1 year ago | 0

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Memory efficient alternative for meshgrid?
This is how to make the three-loop version analogous to the meshgrid version % some dummy values N = 300; x = linspace(1,10,N...

1 year ago | 0

Sorting Equal Elements of Matrix into Groups in Cell Array
I had the same problem to detect isolated nodes in a graph: conncomp is the matlab command that gets the job done: % create the...

1 year ago | 0

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Error using / Matrix dimensions must agree...
f is a vector, as well as W. So you must use the dotted version of the division (that is ./ that performs the operation elementw...

1 year ago | 0

Question

Copy Matlab Command Window without diary
Hi everyone, I would like to add an optional function command at the end of a script that logs the command window to a file. I...

1 year ago | 2 answers | 0

### 2

Is it possible to create a program on matlab that's works on android?
Sort of https://it.mathworks.com/help/supportpkg/android/run-on-target-hardware.html?s_tid=CRUX_lftnav

1 year ago | 0

How to improve my code speed (for loop)
By profiling, the most computational intensive operations are x=T*(probe-ut)'; y=T*(gallery-ut)'; That calculation is inside ...

1 year ago | 0

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How to optimize only 2 variables in an objective function with 3 variables?
In this case you can set the upper and lower bound for that specific variable to the same value. Maybe it is not efficient but i...

1 year ago | 0

How to optimize only 2 variables in an objective function with 3 variables?
Why don't you remove theta from your objective function definition and call different_function inside function? function object...

1 year ago | 0

How to change a column vector into a square a matrix?
Not as elegant as it could be but it works, especially for small matrices % matrix dimension n = 3; % your entries (here du...

1 year ago | 0

Calculate acceleration from velocity and time fron excel
acceleration = diff(data.Velocity)./diff(data.Time); Note that this vector has one entry less than the original ones, so you ma...

1 year ago | 0

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Subscripted assignment dimension mismatch.
You can use repmat and create a char array function bigstring = string_multiplication(str,N) bigstring = repmat(str,N,1); ...

1 year ago | 0

Simulation errors when multiplying matrices
I start a new clean answer You don't have to use the index i inside your matrix like you are doing in your code: in that way yo...

1 year ago | 0

Solving Complex Matrix Operations
You can do this in a for loop or using arrayfun % your A vector A = rand(1,1001); % dummy vector % calculation of the matr...

1 year ago | 0

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Replicate values in a matrix i-1 times
Quick and dirty for loop A=[1; 4; 8; 3; 2; 6] B = []; for i = 1:length(A) B = [B; repmat(A(i),i,1)]; end You can als...

1 year ago | 0

Find independent variables that minimize function
If you have only lower and upper bounds, use them directly in fmincon % your function fun = @(x) ((x(1)-real(0.5*(x(1)-(sqrt(x...

1 year ago | 0

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Simulation errors when multiplying matrices
Inside the loop in the first instruction Vn(:,i) is 5x1 but T is 5x5. Matlab now (starting in 2016, I guess) implicitly expands ...

1 year ago | 0

Weighted fit using fmincon
How about to repeat the samples of the points you want to weight more?

1 year ago | 1

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how to find the optimal value of a matrix that minimize a function?
If I understand correctly the problem can be recast to the following A*W = B*H = F; [a11 a12; a21 a22]*[w1 w2 0 0; 0 0 w3 w4] ...

1 year ago | 0

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plot 2 3D vectors in Matlab
% vectors a = [1 2 -3]; b = [-3 12 -13]; % starting point C0 = [0 0 0]; % put vector in a matrix, to make the code more...

1 year ago | 0

Error using sparse Index into matrix must be positive.
Simply remove "-1" from the definition of R. randi returns pseudorandom integers between 1 and the first inupt. The entries of C...

1 year ago | 0

How to solve time and space deriavtive using ode45?
Have a look at pdepe: it solves 1-D parabolic and elliptic PDEs

1 year ago | 0

Finite Difference Matrix Help
Edit: I changed my answer including a reference and the second order derivative The coefficients for central differences of dif...

1 year ago | 0

improved Euler integration scheme (possible code error) in matlab
I think it should be "-" p(1) = (-z(1)*(1-(z(2)))); p(2) = z(2)*(1-(z(1)));

1 year ago | 0