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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22 views

DFT of vector $(0, 1, 2, 3)$

The problem is that my answer is different from answer i get in MATLAB. My answer is $(6, -2-2i, -2, -2+2i)$ while MATLAB answer is $(6, -2+2i, -2, -2-2i).$ In MATLAB i use command ...
1
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0answers
21 views

Math notation for expressions using logical (binary) masks on images (matrix)

I need to write up what I have written in matlab: I have an image (that is, a matrix) $K$ and some other matrix of the same size $M$ which acts as a mask which represents the values I would like to ...
2
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1answer
14 views

improving symbolic generation of objective function for optimization

I am currently using matlab to solve an optimization problem. I am generating the objective function using the symbolic toolbox. I planned use the symbolic toolbox to calculate the gradient and ...
2
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0answers
35 views

Creating an ellipsoidal 3D surface

I am trying to find the equation of a 3D ellipsoidal surface. I have thought of two approaches which are schematically shown below: By revolving an elliptical arc over a 3D elliptical path: Or by ...
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1answer
40 views

MATLAB curve fitting - least squares method - wrong “fit” using high degrees

Anyone here that could help me with the following problem? The following code calculates the best polynomial fit to a given data-set, that is; a polynomial of a specified degree. Unfortunately, ...
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1answer
15 views

Compute $\left(a_{i}A+B\right)^{-1},\qquad i=1,\ldots,N$ efficiently?

I need to compute the inverse matrix: $$(a_i A+B)^{-1}, \qquad i=1,\ldots,N$$ where $N$ is a large number. $A$ and $B$ are general $M\times M$ matrices independent of $i$. The only thing that ...
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1answer
31 views

How to define a meshgrid (x,y) between the intersection of two oblique lines.

How can I create a meshgrid to draw a 3d surface in a domain (zone 1) defined by the intersection of two oblique lines in Matlab (see attached figure)1. The variables 0
2
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0answers
79 views

how to use Matlab ifft to calculate the following integral? [duplicate]

$$R(t)=\int_{-\infty}^\infty\dfrac{\omega e^{i\omega t}}{(3-\omega^2)^{2}+4\omega^2}\,d\omega$$ where t is a integer and $t>0$ I used to calculate this integral by numerical integral,but it seems ...
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2answers
45 views

How to use Monte Carlo method to find volume?

So the question asks to use the Monte Carlo method to find the volume of an irregular figure defined as: ...
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34 views

fixed point iteration code [on hold]

So as I was working out my math with the following equations using the fixed point iteration, I stumbled to wonder if one can ever write a C program, MATLAB (or the likes) for such math. So my ...
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1answer
18 views

Matrix Factorization of lower triangular and unit upper triangular.

So I have a matrix. $$A =\begin{bmatrix} 8 && -3 && 2 && -1\\ -3 && 8 && 0 && 2\\ 2 && 0 && 8 && -3\\ ...
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1answer
22 views

Gauss quadrature on tetrahedron

I have the Weights ${\bf w}=[w_1\,w_2\, w_3\, w_4]=[0.25, 0.25, 0.25, 0.25]/6$ and the points ${\bf x_1}=[0.1381966011250105 , 0.1381966011250105 , 0.1381966011250105]$ ${\bf ...
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25 views

Guassian quadrature

Consider the polynomial $L \in P_5$ defined by $$L(x)=\frac{d}{dx^3}(1-x^2)^4$$ My question is to use a technique similar to the one used in the analysis of the Gaussian quadrature to show that Q has ...
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1answer
19 views

Replaces data in a matrix with Matlab

A is a matrix (6 ×6) defined as: A= [0.25 0.35 0.46 0.56 0.67 0.78; 0.25 0.37 0.49 0.61 0.73 0.86; 0.25 0.38 0.52 0.66 1.80 1.94; 0.25 0.40 ...
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0answers
9 views

Optimization of nested models

Hi everyone, I'm programming in Matlab and I have the following optimization problem in calibrating several nested model specifications. Summary: I have two models ($1$ and $2$, $1$ is nested in ...
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1answer
18 views

iterated matrix multiplication in scilab\matlab [closed]

Please help me with my code. I can't write the iteration in codes ...
0
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1answer
12 views

MINLP optimization with matlab reaching different solutions every run

I have written a program for optimizing a set of generators. I have hourly price and cost data and need to figure out when a generator should run or just stay off. I describe the problem in more ...
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0answers
14 views

Polynomial Interpolant [duplicate]

I need to find the polynomial using divided differences with respect to these conditions: $ p(1) = 2 $ $ p(2) = 4 $ $ p(3) = 8 $ $ p'(2) = 4ln(2) $ How do I deal with the condition on the first ...
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1answer
14 views

matlab MINLP optimization with ga

I have written a program for optimizing a set of generators. I have hourly price and cost data and need to figure out when a generator should run or just stay off. There are additional constraints but ...
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0answers
14 views

How to change 1D Metropolis into 2D?

I've written a MATLAB function to generate random numbers from a given univariate distribution using the Metorpolis algorithm. Here it is: ...
0
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1answer
21 views

integer linear programing in matlab with the symbolic toolbox

I am writing a program to optimize a set of generators. I have hourly data and but dont want to necessarily optimize the whole time series. For a similar problem in the past I used the symbolic ...
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1answer
112 views

Matlab simulation of dog chasing a rabbit pursuit curve.

Hi I'm really struggling with this problem of mine. A rabbit is running along the x-axis (0->∞) with a constant velocity vr and a dog chases the rabbit starting at some point L (0...∞) on the y-axis ...
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1answer
59 views

How to draw a 3-D surface between two straight lines [closed]

How can I draw a 3-D surface between two straight lines in Matlab: X=0:0.05:0.25; y1=2*x+1; y2=5*x-2; z=function(x,y)
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0answers
18 views

Matlab Newton's Method Non-linear system

There is something wrong with this program and I cannot seem to find it. I am trying to calculate the solution of a non-linear system using Newton's method. Matlab keeps saying there is a problem with ...
2
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3answers
36 views

MATLAB: matrix multiplication with exponentiation

Normal matrix multiplication computes $C=A*B$, such that $C_{ij}=\sum_k{A_{ik}*B_{kj}}$ I want to compute D, such that $D_{ij}=\sum_k{e^{A_{ik}*B_{kj}}}$ Basically I want to exponentiate each ...
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2answers
5 views

Generating points from bi variate normal mixture densities

I am asked to generate 200 and 1000 points from a bi-variate normal mixture densities. I am trying to understand the algorithm, not just the matlab code (I have to write it, not use an existing ...
1
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1answer
15 views

plotting cone on matlab

Plot the portion of the cone $z=sqrt((x − 1)^2 + y^2)$ inside the cylinder $r = 2$ This is my matlab code. However, I get an error with the ezsurf line. Any ideas as to what I might be doing wrong? ...
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3answers
28 views

determine unit outward normal vector on a curve

It is necessary for me to find unit outward normal vector for the curve: $$\gamma=(x(t),y(t))$$ where $$x(t)=(0.6)\cos(t)-(0.3)\cos(3t)$$ and $$y(t)=(0.7)\sin(t)+(0.07)\sin(7t)+(0.1)\sin(3t)$$ I ...
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0answers
28 views

Dense packing of circles in unit circle, matlab code

I'm having real difficulties with a packing problem: Given M circles with equal radius r, determine the maximum radius such that all the circles can be fitted into the unit circle, without overlap. ...
0
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1answer
10 views

Log-scale in MATLAB's fplot [closed]

How can one use logarithmic scale when using matlabs fplot? Is it possible?
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0answers
9 views

Simulate and present normal distribution [migrated]

My task is to compare different methods of simulating normal distribution. For example, I use following code, to generate 2 vectors, each 1000 values (Box-Muller method): ...
0
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1answer
16 views

Incomplete Cholesky decomposition conjugate gradient method in Matlab

I have a problem in finding the numerical material that describing in detail for incomplete Cholesky combined with conjugate gradient method by using Matlab. Someone can help me? Many thank in ...
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1answer
23 views

Matlab solution for non-homogenous heat equation using finite differences

Given the following PDE (non-homogenous heat equation): $$ u_t(x,t) = c^2u_{xx}(x,t) + f(x,t) $$ $$ u(0,t) = u(l,t) = 0 $$ $$ u(x,0) = g(x) $$ $$ 0 < x < l ; t > 0 ; c > 0 $$ I wrote the ...
0
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1answer
23 views

Matlab Recursion Loop

I need to create a loop to answer part c of the following linear algebra question. I'm new to Matlab so this is extremely confusing. I'm not sure how to make a loop that "counts" from 0-25 in order to ...
0
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0answers
30 views

Searching solution for solving huge linear system in MATLAB or C

I am encountering a problem that my MATLAB code ran and an error occurs and shows that it is out of memory. My code is using finite element method to solve some complicated kind of integral equation ...
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1answer
24 views

Least Squares in Matlab

I'm stuck on part (d) I'm not sure how to code it so that it approximates that function in matlab. I'm also not sure if my (a) thru (c) are correct. But this is what I have so far. ...
0
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2answers
26 views

Matlab code for creating matrix

I have a problem, I am working with numerical approximations. Now i have $-1=x_0<x_1 <...<x_n=1$ with $x_i=x_{i-1}+h$ and $h=2/n$. Now given a function $f$ , I want to find $f(x_i)$ for ...
0
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1answer
21 views

creating a tridiagonal matrix in scilab/matlab

I want to create a tridiagonal matrix in scilab/matlab such that it uses for loops. I dont know how to create the matrix but here is what i have started ...
2
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0answers
31 views

Phase retrieval via SDP (semidefinite program) of 2D test image (Matrix completion)

In SDP based phase retrieval we have intensity measurement (abs(FFT2(x))^2) of the form A(xo) = |ak,x|^2 =b^2, phase retrieval is then find x that obeys A(xo)=b The quadratic measurements can be ...
0
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1answer
36 views

analytic/euler/runge kutta solutions comparison problem

i've been trying to solve 1st order differential equations with dsolve, euler andy runge kutta methods and compare them on graphics. for simplification, dy means dy/dx: first equation is y' = ...
1
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1answer
31 views

How to find the zeros of an integral?

I am having trouble finding the roots of an integral. For example $F(c)=\int_a^b{(x^2-c^2)}dx$ for some finite interval $[a,b]$. The problem is that I am trying to do this using numerical analysis. ...
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1answer
18 views

Matlab help to construct matrices with specified rank and such that each eigenvalue is real

I am reading this paper, where at page $68$, section 3.3 (numerical examples for the Drazin inverse), the randomly generated matrix with specified rank and with the property that each eigenvalue is ...
1
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1answer
29 views

Linear Algebra Matlab matrix loop?

I'm new to both linear algebra and Matlab, so naturally I'm probably asking an obvious question. If someone could attempt to explain to me in layman's terms how to go about answering this question in ...
1
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0answers
18 views

Discretization of a convolution integral for constrained optimization problem

I'm working on a constrained optimization problem in which an unknown forcing function, $u(\eta)$, is in the integrand of a convolution integral. To find an optimal shape for $u(\eta)$, the integral ...
1
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1answer
23 views

Hand calculation of magnitude of transfer function doesn't equal what MATLAB says…

I have a simple transfer function, given by: $$\frac{140,000}{s(s+100)}$$ I'm attempting to calculate the magnitude at $\omega$ = 100 rad/s. So I plug in, I get $\frac{140,000}{20,000}$ = 7 Then I ...
0
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1answer
15 views

Random sampling using Metropolis vs. Accept-Reject

I'm working on a project comparing the accept-reject (von Neumann) and Metropolis methods of sampling. I'm generating a sample of size $N$ from a normal distribution $N(1,(\frac{1}{2})^2)$. What I ...
22
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3answers
1k views

Matlab wrong cube root

How can I get MATLAB to calculate $(-1)^{1/3}$ as $-1$? Why is it giving me $0.5000 + 0.8660i$ as solution? I have same problem with $({-1\over0.1690})^{1/3}$ which should be negative.
-1
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0answers
17 views

euclidean distance in matlab

2-class classication task in the 2-dimensional space, where the two classes, w1 and w2, are modeled by Gaussian distributions with means m1 = [0; 0]T and m2 = [1; 2]T , respectively. Assume the two ...
1
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1answer
48 views

Incorrect indefinite integral on MATLAB?

any ideas why matlab is giving me an incorrect answer here? 1 set of commands syms x L N2 N2 = 6*x/L^2 - 2/L^2 N2 = (6*x)/L^2 - 2/L^2 expand(int(N2*N2)) ans = ...
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0answers
12 views

How to use the Euclidean distance classifier to classify the test points compared with the trained points?

used d = mahal(test_data,training_data); for the Mahalanobis distance classi fier lassify the test points compared with the trained points. Is there any such way to identify the Euclidian distance ...