Community Profile

photo

Matt J


6,124 total contributions since 2009

Professional Interests: medical image processing, optimization algorithms

PLEASE NOTE: I do not read email sent through my author page. Please post questions about FEX submissions in their respective Comments section.

Contact

Matt J's Badges

  • Personal Best Downloads Level 4
  • First Review
  • 5-Star Galaxy Level 5
  • First Submission
  • Master
  • Revival Level 4
  • 36 Month Streak
  • Thankful Level 4
  • Knowledgeable Level 4
  • First Answer

View details...

Contributions in
View by

Answered
The best way to code this optimization problem
It should be very straightforward using the problem-based solvers in the Optimization Toolbox, https://www.mathworks.com/help/o...

31 minutes ago | 0

Answered
how do i create a random matrix with set size yet the numbers are in a range from 0-9
randi([0,9],4,6) %random integers or 9*rand(4,6) %non-integers

1 hour ago | 0

Answered
Error while using blockproc. Matrix dimensions must agree.
Matrix dimensions must agree. Error in dct (line 76) b = W .* fft(y); It would appear that W and y are not the same size....

1 day ago | 1

| accepted

Answered
Form a 3D matrix for a 2d matrix
NewM3D = reshape(ExitVector,size(M3D));

1 day ago | 0

Answered
how can i bound rate of changes (dx/dt) in fmincon optimization?
See https://www.mathworks.com/matlabcentral/answers/490758-limit-on-the-change-rate-of-the-variable-in-fmincon-function#answer_...

1 day ago | 0

Answered
Limit on the change rate of the variable in fmincon function
You would build linear inequality matrices like the following. E=diff(eye(numel(u))); A=[E;-E]; b=[ub(:);-lb(:)]; %linear ...

1 day ago | 1

Answered
Multiplication in cell arrays
result = cat(3,precip{:}).*reshape(numbers,1,1,[]); There seems little reason either for precip to be a cell array or to turn t...

1 day ago | 0

Answered
Regular expression for 1*1 cell array
c='<string_attribute name="country"><s>CHINA5</s></string_attribute>'; out=extractBetween(c,'<s>','</s>'); >> out{1} an...

2 days ago | 1

Answered
Weighted fit with lsqcurvefit and (ideally) multistart?
Just apply whatever weights you want to the objective and to your ydata, fun=@(x,xdata)kinetics_full(x,xdata).*sqrt(weights); ...

2 days ago | 0

Answered
Rotate matrix with interp2
This might be what you want. [X,Y]=meshgrid(x-mean(x),y-mean(y));

2 days ago | 0

| accepted

Answered
Finding angle of rotations from a given unit vector to rotate a given vector using those angle to align with the previous unit vector
The following might be what you're looking for. It uses my AxelRot utility from the File Exchange https://www.mathworks.com/mat...

3 days ago | 0

| accepted

Answered
Nested For Loop for 2D Matrix
I vaguely wonder whether you are just re-inventing convolution result = conv2(Matrix,staticMatrix,'valid');

3 days ago | 0

Answered
Nested For Loop for 2D Matrix
So then you want to extract random 51x51 submatrices? If so, then, I=sort(randperm(600,51)); J=sort(randperm(1000,51)); sub...

3 days ago | 0

| accepted

Answered
The result of rotation matrix rotx(angle) with a coordinate does not give the desired result
Here's what my AxelRot utility gives https://www.mathworks.com/matlabcentral/fileexchange/30864-3d-rotation-about-shifted-axis?...

3 days ago | 0

Answered
how can I find the coordinates of the central axis of a river in an image (binary)?
load River C=watershed(bwdist(A))==0; [icoords,jcoords]=find(C); %coordinates of center line imshow(A+C)

3 days ago | 2

| accepted

Answered
Count the number of intersections between any two curves
The only general way (i.e., for arbitrary curves) is using the Symbolic Math Toolbox, solve(curve1==curve2)

3 days ago | 1

Answered
How to match a number between two characters?
>> str=extractBetween("[180] Windabweichung","[","]") str = "180"

3 days ago | 0

| accepted

Answered
How to match a number between two characters?
>> T=regexp('[180] Windabweichung','\[(\d+)\]','tokens'); T{:} ans = 1×1 cell array {'180'}

3 days ago | 0

Answered
Images as the Options in a Drop Down Menu
See here, https://undocumentedmatlab.com/blog/icon-images-in-matlab-uicontrols

4 days ago | 1

Answered
License Manager error -96 (of matlab 2018b)
This may help https://www.mathworks.com/matlabcentral/answers/95122-why-do-i-receive-license-manager-error-96?s_tid=answers_rc1...

6 days ago | 0

Answered
how can i find the stationary points of this equation and find its nature in the region x>0.
You can use diff to get numerical approximations of the derivatives and apply stationary point criteria based on those. If need...

6 days ago | 0

Answered
The best way to write a large number of constraints for an optimization problem
If they are linear constraints, they will be expressed using matrix-vector multiplication A*x<=b Aeq*x<=beq so any vectorized...

8 days ago | 0

| accepted

Answered
How do I remove NaN values from a cell array?
The presence of NaNs isn't the problem. The problem is that the cell contents are character vectors of different lengths. You ca...

8 days ago | 0

| accepted

Answered
Fmincon linear contraint doens't work in my case
You should check the EXITFLAG output to see if fmincon believes it converged. If it did converge, the ranges should be satisfied...

9 days ago | 0

Answered
How can i create a convolution using toeplitz matrix?
Consider >> x=1:5, y=rand(1,5), x = 1 2 3 4 5 y = 0.2899 0.4714 0.8782 0.6555 ...

9 days ago | 0

| accepted

Answered
fminunc: get Hessian approximation after each iteration
You could try running fminunc 1 iteration at a time in a for-loop and saving the 6th output arguments, options.MaxIter=1; ...

9 days ago | 0

| accepted

Answered
Using FFT in for-loop is extremely slow - how to accelerate?
To conserve memory, I only store the results for x,y,z inside the mask. It would be straightforward to re-embed them in 4D array...

9 days ago | 0

Answered
Can someone propose some code that will "connect the dots" to produce the correct geometric shapes (i.e., hexagons, pentagons, rectangles) from these points?
Here is a refinement of my earlier answer which I think performs better. It uses the attached classdef file to create objects re...

10 days ago | 1

Answered
Create matrix (30 x 12) with numbers from 1 to 12 without repetition without any repetitions of following numbers for each row
Note that there are only >> nchoosek(12,2)*2 ans = 132 distinct subsequences of length 2 that can be drawn from the numbe...

10 days ago | 0

Answered
Can someone propose some code that will "connect the dots" to produce the correct geometric shapes (i.e., hexagons, pentagons, rectangles) from these points?
This seems to do it. For the display part, it uses plotpts2d, which you've seen before. maxDistLine=10; %User tolerance s...

13 days ago | 0

| accepted

Load more