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Matt J


5.931 total contributions since 2009

Professional Interests: medical image processing, optimization algorithms

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Answered
How to deblur an image after gauss filter and image registration?
Use imregtform to perform the registration on the blurred images and to obtain the optimal tform. Then apply the tform to your o...

alrededor de 14 horas ago | 0

Answered
How to find the (x,y) combinations that make z=0?
You can use fimplicit https://www.mathworks.com/help/matlab/ref/fimplicit.html

alrededor de 16 horas ago | 0

Answered
Plotting a for loop
C=nan(1,101); F=C; %preallocate for i = 0:100; C(i+1) = i; F(i+1) = (i*1.8)+32; end plot (C,F) xlabel(...

alrededor de 17 horas ago | 0

Answered
fsolve with functions inside script
A=3; B=2; x0=1; fsolve(@(x)fun(A,B,x) ,x0); function F=fun(A,B,x) A=A; B=B; F=A+B/x end

alrededor de 21 horas ago | 0

Answered
Find the cell index in a nested cell array, corresponding to a string (by using strcmp)
B=cellfun(@(x) strcmp(x, 'BLUE'), A, 'UniformOutput', false); cellfun(@(c) any(c(:)), B)

alrededor de 22 horas ago | 1

| accepted

Answered
Remove rows in variable dimension
idx=repmat({':'},1,ndims(M)); idx{dim}=1:size(M,dim)-N; M2=M(idx{:})

alrededor de 22 horas ago | 0

| accepted

Answered
How to set up the following optimisaiton witth quadprog?
You haven't shown any constraints. Are you sure you couldn't just use lscov? If you do have constraints, I think lsqlin would b...

alrededor de 23 horas ago | 0

| accepted

Answered
Error using horzcat Dimensions of matrices being concatenated are not consistent.
I suspect it is because y is a column vector, whereas you intended it to be a row vector. You should run the code with "Pause on...

alrededor de 23 horas ago | 0

Answered
object detection in a binary image
>> bwimage=imbinarize(rgb2gray(imread('bwimage.jpg'))); >> locations=regionprops('table',~bwimage,'Centroid') locations = ...

4 días ago | 0

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Answered
Main diagonal operations problem
x=eye(4); x(1:5:end)=0.7*rand(4,1)+0.3

4 días ago | 1

Answered
Unique rows of 2 cells with 2 columns each.
I tried the following 2 codes: unique(vertcat(IdxMembers,IdxMembers2),'rows')... I get the unique values in dim (nr. of unique v...

4 días ago | 0

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Answered
how to sort variable of an array?
sort(M,'descend')

4 días ago | 0

Answered
confront values in 2 matrix
min(A(1,:), B(1,:))

4 días ago | 2

Answered
Mean matrix of different size matrices in one cell array
cellfun( @(a)mean(a(:)) , A)

4 días ago | 0

Answered
upper and lower curves
You can use the quantile command https://www.mathworks.com/help/stats/quantile.html to determine the upper and lower quartiles...

5 días ago | 0

Answered
Adjust regionprops orientation in order to get 360 degree value.
theta = 90-Orientation assuming theta increases clockwise.

5 días ago | 0

Answered
using lsqcurvefit with normalized error
This way I get a good fit but then I cannot plot the 95% confidence interval. fmincon doesn't return the Jacobian, but it does ...

6 días ago | 1

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Answered
fmincon is nonlinear constraints satisfied, then not satisfied when I include objective function
The algorithms of fmincon try only to satisfy the nonlinear and A,b,Aeq,beq constraints at convergence. They do not pledge to sa...

6 días ago | 0

Answered
Question about for loop problem
I don't see any mistakes (that's why posting your error messages and output is always a good thing), however, the whole thing ca...

6 días ago | 0

Answered
How to find the indices that a point lays between?
Do you suggest another way? In case X is not increasing. If X,Y are non-monotonic, I would do [~,points] = pdist2([X(:),Y(:)],...

6 días ago | 1

Answered
How to find the indices that a point lays between?
find is inefficient. You should instead do, point1=discretize(xA,X); point2=point1+1;

6 días ago | 0

Answered
Split array into multiple columns based on another array
result = splitapply(@(x) {x}, DHB_combine,index_combine);

6 días ago | 0

Answered
how to plot a fitness or objective function with optimum values
Sounds like you want this? options = optimoptions('ga','PlotFcn',{'gaplotbestf','gaplotbestindiv'}); [x,fval] = ga(Objective...

6 días ago | 0

Answered
Multi-objective optimisation using results from external simulation
MATLAB optimization solvers require that you provide a function which take a guess of your unknowns as input and return the quan...

6 días ago | 1

Answered
Subset multidimensional array using a vector
idx=repmat({':'},1,ndims(A)); idx(1:numel(v))=num2cell(v); result=A(idx{:});

7 días ago | 1

Answered
Sorting and averaging matrices
[~,idx]=sort( reshape(A,8,[]) ,1); [m,n]=size(idx); C=reshape(B,m,n,[]); [m,n,p]=size(C); idx=i...

7 días ago | 2

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Answered
fmincon command to find minimum value of Rosenbrock's function in Polygonal domain
You have miscalculated your A and b. You can use vert2lcon to obtain them automatically, https://www.mathworks.com/matlabcentra...

7 días ago | 0

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Answered
Action shot function with multiple images
Yes, here is an approach that uses no loops, Image4D=double(cat(4,ImageCell{:})); MedianImage = median(Image4D,4); [~,idx...

8 días ago | 3

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Answered
Undefined function for input arguments of type 'double': how do I make them vectors and not doubles?
Here is the non-symbolic approach mentioned by Adam. function[val,g,H]=givenfGNM(x) %givenf() modified to output the Hessian a...

8 días ago | 1

Answered
Removing object from image using median filter
I'll call your 1xn cell array of images ImageCell. Then I think you want, Image4D=cat(4,ImageCell{:}); R=median( Image4D(:,:...

8 días ago | 2

| accepted

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