Community Profile # Matt J

Last seen: Today Active since 2009

Professional Interests: medical image processing, optimization algorithms

#### Statistics

All
• • • • • • • • • • #### Content Feed

View by

using fsolve function to solve for 2 unknowns
x0 = [80,110]; [sol, Fsol] = fsolve(@problem_one,x0), function F = problem_one(theta) theta3 = theta(1); theta4 ...

en dag ago | 1

| accepted

fminunc initial point is local minimum, but fminsearch returns reasonable estaimtes
It could happen if your objective function is piece-wise flat (and hence non-differentiable). fminsearch is a derivative-free so...

en dag ago | 0

| accepted

How can I obtain the Fourier Transformation as a product of matrices?
N = (0:255).'; X = (2*cos(((15.8*pi)/128)*N)) + (3*sin(((27.3*pi)/128)*N)); F=fft( eye(numel(X)), [],1); fX = fft(X); %...

en dag ago | 0

| accepted

How to plot binary matrix as dots?
imshow(yourMatrix)

en dag ago | 0

Solving non linear equation "Circle" equations
Because you cannot be certain of an exact 3-way (or n-way) intersection, you need to use a numerical least squares solver like f...

en dag ago | 1

| accepted

What is the real value of "single(my_variable)"?
So the C code keeps good precission. But, does Matlab? Yes, if by "good precision" you mean up to 7 digits. You can see that ev...

en dag ago | 0

How to define a constat in function handle?
You mean like this? [a,b,c]=deal(3,4,5); f = @(x,y)a*x.^2+b*y+c Or like this? syms x y a b c f(x,y) f(x,y)=a*x.^2+b*y+...

en dag ago | 0

| accepted

Steepest descent with exact line search method
n=input("Enter the roll number:"); fobj=@(x) (x(1)-n)^2 + (x(2)-2*n)^2; gradobj=@(x)2*[(x(1)-n), (x(2)-2*n)]; x0=[1 1]; ...

en dag ago | 0

how to develope loop to save the 'n' elements from the vectors
It is not a good idea to store A(i) in separate variables. You should probably just write your equation in terms of vector opera...

en dag ago | 2

Taylor series approximation problem
As an example, syms x T=taylor(exp(-x),x,7,'Order',4) fn=matlabFunction(T) fn(3) You can of course find more examples...

en dag ago | 0

how can I call a class in a gui?
I have defined a class TimeData by a script Don't you mean you defined it in a classdef file? The constructor function for a c...

2 dagar ago | 0

Trying to supply fsolve with system's Jacobian but receiving error ''check for incorrect argument data type"
It is not clear (from what you posted), why you are using symbolic variable manipulation at all. fsolve is a numerical solver, n...

2 dagar ago | 0

Rotate Values of Matrix
Use imtranslate() to center the source in the image, then use imrotate() it by the desired angle, then use imtranslate() once mo...

2 dagar ago | 0

Get the last for digits as the time this message was sent
Is this what you want? str=char( "!AIVDM,1,1,,A,13cut>1001P:3LRGa`P@jip400S<,0*410002" ) str(end-3:end)

2 dagar ago | 1

| accepted

Is it possible to set an upper limit on the step size used by fsolve?
You could try playing with the InitDampling option parameter used by the Levenberg-Marquardt method.

3 dagar ago | 0

Am I understanding this correctly?
If by "low" you mean zero and by "high" you mean 255, then yes.

3 dagar ago | 0

Not sure why while loop won't run.
balance(1) = 1000; contribution = 1200; interest = 0.0025; M = 2; % month ticker while balance(end) < 500000 ba...

3 dagar ago | 2

| accepted

How select data just out from a polygon, considering a constraint
borders=[0,0;0,1;1 1;1 0]; p=polyshape(borders); p=blurHull(p,[0.3,0]); p=blurHull(p,[0, 0.1]); isinterior(p,datas) ...

3 dagar ago | 0

| accepted

Creating Matrix Subset automatic.
You should be doing it as follows: S=A([1,4,7],:);

3 dagar ago | 0

| accepted

How can I sort vector according to its index?
[vect,ind]=sort(vect,'descend')

3 dagar ago | 0

Plotting Phase Plane in Matlab
For example, funx=@(t) c1*exp(-3*t)+c2*exp(-t); funy=@(t) -c1*exp(-3*t); fplot(funx,funy,[0,1]) or t=linspace(0,1,100); ...

4 dagar ago | 0

Unable to perform assignment because the indices on the left side are not compatible with the size of the right side
parfor i=1:16000 tmp=double(solve(f==A(i),x)); if isempty(tmp), warning 'No sol...

4 dagar ago | 1

| accepted

Newton's method
Tab=[]; for x = -1:0.05:5 Tab = [Tab , newton(@f1,@df1,x,10^(-8)) ] end

4 dagar ago | 0

| accepted

add a row to a matrix each loop
Just concatenate: A=eye(5) newrow=rand(1,5); A=[A;newrow]

4 dagar ago | 0

Registering two images where the camera has translated
The default multi-modal options seem to work pretty well. imreader=@(z,s) imresize(rgb2gray(imread(z)),s); %Register at ...

4 dagar ago | 0

How to draw 9 cones using kronecker product?
If you have the matrix of surface values of a single cone, you could simply do, surf(kron(ones(3), singleCone))

4 dagar ago | 0

Why does my matrix give me a syntax error
(It follows the END that terminates the definition of the function "Fnorm".) That is not allowed. All local functions must be p...

5 dagar ago | 0

How can I make MATLAB shade the area of the virtual intersection between two lines?
You can use fill() or patch().

5 dagar ago | 1