MATLAB is a high-level language and interactive programming environment for numerical computation and visualization developed by MathWorks. MATLAB can be used when performing tasks such as signal processing and communications, image and video processing, computational finance, and computational ... ...

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Given a data set of random values in MATLAB, how do I plot its PDF?

Suppose I have the following code in MATLAB: ...
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Implementing High Pass Filter in Simulink

I am trying to implement the following block diagram using Simulink in Matlab. I am having trouble getting the high pass filters to work properly. To do the filtering, I am using the First and ...
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1answer
18 views

Matlab: variable-dependent dot product in anonymous function

I have an anonymous function like this one: f = @(t) 5.*cos(t) + 10.*sin(t); f([1,2]) ans = 11.1162 7.0122 Is it possible to define f using a dot product ...
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9 views

Invoking function with given coefficient in matlab

I have a $test.m$ with a function document $duff.m$ $test.m$ clc clear all [t,x]=ode23('duff',[0 100],[0 0]); y=size(x); plot(t,x); and $duff.m$ function ...
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Solving Duffing equation by Matlab ode23

How can I use Matlab to solve numerically this duffing equation with known $\kappa, \Gamma, \omega$..thanks.. $$x'' +\kappa x' +x -x^3 =\Gamma \cos\omega t$$ I have only few knowledge of Matlab..
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1answer
15 views

Some operation like determinant

we have determinant operation that is like below: $ det(\begin{bmatrix} a & b & c \\ d & e & f \\ g & h & i \\ \end{bmatrix}) $= $ (-1)^{1+1}a(ei-fh)+ ...
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1answer
23 views

Analytical solution for bound state energies of infinite well

I am trying to find bound state energies assuming infinite potential. I have been told it can be done by analytically solving Right Hand Side and Left Hand Side of an equation such as: ...
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47 views

How to find nonnegative solutions of a linear system?

I have a $M$ equation and $N$ variables like this : $ \begin{bmatrix} 3 & 0 & 1 & 0 & -1 & -3 & 2\\ 1 & 2 & 0 & 4 & 0 & 0 & -1\\ 1 & 1 & 0 ...
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15 views

Speed of Fisher Kolmogorov Wave equation in Matlab [on hold]

I have a working code for the Fisher Kolmogorov equation. Now I want to find the speed at which the wave is propagating. And that calculation would be : (x coordinate of U at time t+ delta t) - x ...
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1answer
14 views

How to plot median with 10% and 90% percentiles

I have to make a plot of same data (I do it in Matlab). On the x-axis the time (in seconds) and on the y-axis the response time (in ms). Now I have to do it with "Median with 10% and 90% ...
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24 views

Pleas help me MATLAB! [closed]

I want to build an algorithm about following; z=linspace(1+i, 10+5i); a=z^2; plot(a) ??? Error using ==> mpower Inputs must be a scalar and a square matrix. It is easy to plot z^2 by hand... but ...
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32 views

How to calculate a complex integral with branch cut?

I want to calculate this integral: $$\int_{-\infty}^{\infty} \frac{\exp\left(-i\sqrt{(\xi^2 - k^2)(y -y')} -i\xi(x - x')\right)}{-i\sqrt{\xi^2 - k^2}}d\xi$$ I can not calculate this integral, I can ...
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21 views

Simulating a controlled dynamical system

I am try to simulate a controlled dynamical system of the form $$\dot{x}=f(x,\phi(x)),$$ where $\phi$ is the controller. To do so, I am using Octave (an open source version of Matlab). My commands ...
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18 views

Matlab Code about evaluating Newton Polynomials

I am trying to write a code for evaluating a newton polynomial with coefficients $a = [a_0 , ... , a_n]$, and nodes $x = [x_0 , ... , x_n]$ at the vector $t$, using nested multiplication. ...
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20 views

how does the following parameters affect the peak ( radius ,theta) of the its frequency spectrum?

The following is the similar magnified picture to the second image that it indicates the parameter i am going to talk about. Suppose i am going to fourier transform (DFT) of the following picture ...
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32 views

How to plot fourier series in matlab

For homework (with no prior experience in matlab, guh.) I'm asked to do the following: Plot the (2N + 1)-term approximation $$\sum\limits_{k=-N}^N{a_ke^{jk\omega_0t}}$$ where $a_k = ...
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1answer
17 views

Why is matlab giving me a single answer when I divide by a vector?

I'm attempting to do a stem plot of $\frac{sin(k2D\pi)}{k\pi}$ in matlab. Following is my procedure: ...
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4answers
49 views

matlab get lower triangular matrix without loop and build in function

I tried to get the lower triangular n x n matrix without using any loop or build in function (except size()). is it even possible? I tried something like this: ...
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14 views

How to work around this apparent bug in fmincon (Matlab)?

I try to determine a maximum likelihood estimate using the Matlab routine fmincon. This routine needs as input an initial 'guess' $x_0$. For some values of $x_0$ it gets stuck in an infinite loop, ...
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26 views

PDE using $\theta$ method in Matlab

I'm trying to solve this problem numerically in Matlab: $ \left\{ \begin{array}{rl} \frac{\partial P}{\partial t} &= \frac{\partial^2 P}{\partial x^2} \ \ \ (\star) \\ P(x,0) &= 1 \\ ...
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34 views

MATLAB linear interpolation

I'm trying to write a MATLAB program to do linear interpolation and to check its accuracy. I have to input $x_0$ and $x_1$ and then generate the data values using $y=e^x$. Then, for a variety of ...
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1answer
20 views

Iterative Scheme-Programming Matlab

I don't know if this is going to seem like a dumb question, I am new to this and to matlab, but I'm trying to construct an iterative scheme in MATLAB to compute $\sqrt(b)$ for a given b>0, and program ...
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2answers
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function with moving average on matlab

Do a function that maintains moving average, the function gives the average of all the numbers that have been put in the function. does anyone know how to do this ?
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84 views

what is the probability to find the a sequence of 5 or more continuous heads in coin tossing 100 times?

If an unbiased coin is tossed 100 times, what is the probability to find the a sequence of 5 or more continuous heads in the experiment? My Professor says there is no exact way (may be he meant easy ...
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30 views

Plotting null and column space of C

I can't figure out how to properly plot the null and column space of a certain matrix $C = \begin{pmatrix} 6 & -12 & 6 \\ 12 & -36 & 18 \\ 18 & -36 & 18 \end{pmatrix} ...
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Matlab Code for substituting numbers in variable matrix

In Matlab, if we input a number matrix say [1 2; 3 4; 5 6], then what should i do so that the output would be of the form $ [(x_i-z)^b \hspace{5mm} y_i]$ where $z$ and $b$ are just variables. ...
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1answer
14 views

Matlab %e meaning

What does %e mean in matlab? I.e: x = %1.25e I know if you put an e at the end it adds 0s, so does it have something to do with that?
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1answer
34 views

How can I plot a 2D figure in MATLAB by “connecting the dots”?

I'm an amateur at MATLAB and I know how to do the basic stuff such as plotting functions, writing M files, functions, for loops, etc but I've be tasked to do something I have never done before. I ...
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1answer
10 views

Working with piecewise answer in MATLAB

Sometimes MatLab gives me answer in piecewise notation, like this: piecewise([1 < x, 0], [abs(x) < 1, -(log(x - 1) - 1)*(x - 1)]) Is it possible to take ...
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28 views

How do I compose a voronoi diagram?

I am trying to understand the algorithm of plotting a voronoi diagram. Here is a code I developed using whatever I could get off wikipedia. However the implementation is very slow and the complexity ...
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21 views

Resize an image along rows only or columns only in matlab

I'm writing a function in matlab to zoom or shrink an image using bicubic interpolation. However, my function resizes an image along both rows and columns. What if I want to enlarge the image along ...
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11 views

Localizing Region-Based Active Contours

I am working in Lankton paper Localizing Region-Based Active Contours that has to do with localized active contours and especially in mean separation energy part. I am stuck in a point that I cannot ...
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20 views

Creating a tridiagonal matrix in Matlab with smaller matrices

This is the problem. Given a matrix B = \begin{bmatrix} 6&-1&0\\-1&6&-1\\0&-1&6 \end{bmatrix}. and I = 3 x 3 identity matrix, how can I construct D = \begin{bmatrix} ...
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reducing data that are very close to one another

so, I have this problem. I have to do image analysis to get the boundary of an image. I perform image analysis to get a boundary representation of the object. The problem is, there is an overlap of ...
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1answer
57 views

MATLAB Mathematics Question

I have an exam coming up and I need help. Please give full coding and explain. I find code very confusing. Thank you very much :) Euler’s Method a. In the Matlab command window, write a procedure ...
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15 views

How to correctly apply Newton-Raphson method to Forward Euler method?

I have a differential equation X' = -X - (X^2)/5. I want to solve the differential using Forward Euler Method and then finding the root of it using Newton-Raphson Method. I'm using MatLab for this. So ...
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2answers
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Differential Equation Model ODE45 Matlab

The following system of differential equations is intended to be solved with the usage of matlabs ode45 function: $\frac{d\theta}{dt} = w(t)$ $\frac{dw}{dt} = \frac{1}{0.85s}(160 rad/s*u(t) - ...
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1answer
21 views

Use eig and svd syntax in matlab to find complex eigenvalues of a matrix

For matrix $A= \left( \begin{array}{c} 1 & 1 \\ -1 & 1 \\ \end{array} \right) $ when I calculate the eigenvalues (without matlab) , I find $\lambda_1=1+1i$ and $\lambda_1=1-1i$ and when I ...
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12 views

Intial conditions for second order differential equations using MATLAB

I'm trying to solve the following differential equation using MATLAB's ode45 $$ y'' = \alpha (e^{-y} -1) - \beta (e^{y} - 1) $$ for given values of $\alpha$ and $\beta$. However I have the initial ...
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41 views

How to Extract the dual feasible search directions for the primal-dual potential reduction algorithm?

I am trying to implement the 4.4 Primal-dual potential reduction algorithm introduced in M.S Lobo et al.. Here is a screenshot depicts the algorithm flow: As ...
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28 views

Solve linear system with matlab

In my problem, $A$ is a $m \times n$ matrix with $m \geq n$ and $\mathrm{rank}(A)= n$. Let $\Gamma$ be the $(m+n) \times n$ matrix defined by : $$ \Gamma = \begin{bmatrix} A \\ \mathrm{I_{n}} ...
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36 views

10 random observations

I have to generate $10$ random numbers with mean $= 22.6$ and standard deviation $= 2.4$. Then I have to see if the $10$ observations appear to be normally distributed. When I generate $10$ random ...
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1answer
18 views

Computing Polygonal Surface in Matlab

I am given a bunch of points in 3D-space and want to analyze their convex hull. What I am interested in is what kinds of polygons appear on the surface of the convex hull (probably mostly triangles, ...
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1answer
31 views

Partial Fraction Expansion in MATLAB

I am to use MATLAB to find the partial fraction expansion of the following function. Can this be done in that format or do I have to manipulate the function? Note: This must be done using pure MATLAB ...
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Finding where plots may cross with octave / matlab

I have several data points that are plotted below and I would like to find the frequency value when the amplitude value crosses 4. I've included an example along with the data points in the example ...
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31 views

Boundary Conditions for a Finite Difference Approximation of a Sixth Derivative

I am trying to use a finite difference scheme to numerically solve sixth order parabolic equations such as \begin{equation} u_t = u_{xxxxxx} \end{equation} with symmetry conditions \begin{equation} ...