Matt J
Professional Interests: medical image processing, optimization algorithms
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Content Feed
Checking inverse of convolution theorem
You need to use circulant convolution, rather than linear convolution. Also, your fftshift must be applied to the output of the ...
alrededor de 12 horas ago | 1
| accepted
How to Reduce image size and increase size
Here is an example, https://www.mathworks.com/help/matlab/ref/imresize.html#mw_0a904a96-3d99-4878-b28f-cdf6f0d7ca0c
alrededor de 14 horas ago | 0
Why do I get Cannot fit Power functions to data where X has nonpositive values when using the curve fitting tool?
Torsten's idea for an exp1 fit works pretty well. load myfile f=fit(x,y,'exp1'); plot(f,x,y)
alrededor de 15 horas ago | 0
Make optimiser more robust to upper and lower bounds
The problem might be due to insufficient or low quality data. The optimizer is therefore relying more on the bounds than the phy...
1 día ago | 0
I want to only interpolate shorter amounts of data and leave the longer amounts of NaN not interpolated.
If more than x NaN's in a row, then do not interpolate that chunk of data Using function from here, https://www.mathworks.com...
1 día ago | 0
How do I extract each value from a column matrix and subsitute in a equation?
Change all of your '*' operators to elementwise operator '.*' res=@(z) reshape(z,1,1,[]); phi = res( comb(1,:) ); theta = r...
1 día ago | 0
| accepted
Extracting a subset from the Faces and Vertices
[m,n]=size(FacesSub); [Indices,~,FacesSub]=unique(FacesSub); FacesSub=reshape(FacesSub,m,n); VerticesSub = Vertices(Ind...
1 día ago | 0
| accepted
Gamultibojective Problem "Not enough input arguments." Error
x = gamultiobj(@my_objfunction,2);
1 día ago | 0
| accepted
Why does my for loop cause MATLAB to not stop running?
In the code as you've posted it, the for-loop is never closed by an "end". That would prevent it from continuing to the next ite...
1 día ago | 1
| accepted
Plot an ellipse using an equation
fimplicit(@(x,y) 4*x.^2 +25*y.^2 - 32*x - 100*y+64)
2 días ago | 0
| accepted
implicit expansion for arrayfun
A=rand(10,5); B=3; C=rand(10,1); D=rand(1,5); args={A,B,C,D}; sz=cellfun(@size,args,'uni',0); maxsz=max(vertcat(sz{:})); ...
2 días ago | 0
Delete m consecutive rows every n rows
m = 6; n = 24; N = 87; data = (1:N).'+(0:10:20); % some data discard=repelem( [false;true] , [n;m], ceil(N/(m+n)) ); ...
2 días ago | 1
Run interpolation for several datasets at once
x and y used to be both vectors with constant spacing (x and y have their own spacing constant). which have been meshed. Let's...
3 días ago | 0
Run interpolation for several datasets at once
If it's gridded interpolation, you shouldn't be using griddata. You should be using interp2. for i=1:N x_Wake = x(:,:,i)...
3 días ago | 0
Write the MATLAB program using fzero
Documentation and examples for fzero: https://www.mathworks.com/help/matlab/ref/fzero.html
3 días ago | 0
How do I efficiently add values of same indices to a vector?
vec1=vec1+accumarray(ind(:),vec2(:),size(vec1));
3 días ago | 1
| accepted
Cropping 3D image into equal size
If the idea is to split A into cell array cells, using imcrop3 is a little over-elaborate. Consider using mat2cell or download m...
3 días ago | 0
| accepted
Help with linear optimisation problem
Diffs=abs(reshape(B,1,1,[])-A); d=min(Diffs,[],3); [Arows,Acols]=find(d==min(d(:)));
3 días ago | 0
Question
How does one set the PatientPosition and other spatial attributes when writing a dicom CT volume?
I am trying to write DICOMs of a CT volume in both single- and multi-file form. To check that the result is readable, I try read...
3 días ago | 0 answers | 0
0
answersHow to automatically obtain shape coordinates
Perhaps as follows load Image B=medfilt2(A,[5,5])<60; B=bwareafilt(B,5) & ~bwareafilt(B,1); T=regionprops('table',B,'Cen...
4 días ago | 0
Why is my array sending data back in E notation?
That's just the way Matlab displays things by default in the command window . There are other styles which you can set using the...
4 días ago | 1
| accepted
Define function with nonlinear equation system vercat error
F = @(x)[sqrt( (101 - x(1)).^2 + (16 - x(2)).^2 + (207 - x(3)).^2 )+ x(4)- 310.5685; sqrt( (52 - x(1)).^2 + (21 - x(2))....
4 días ago | 1
Solving a nonlinear equation using fsolve. cant reach at perfect result. output showing some error written below.
Result must be around 22-25. but itc coming .0029. As the plot shows, your function has no roots in the range 22-25 p = 1; ...
4 días ago | 0
| accepted
Short Length Convolution Speed Up
From the documentation, it appears that the faster performance of fftfilt is indeed expected: When the input signal is relati...
4 días ago | 0
| accepted
Short Length Convolution Speed Up
Do you have the Parallel Computing Toolbox and a decently powerful GPU? If so, filter() is enabled for gpuArrays.
4 días ago | 0
Using mat2cell
You can use mat2tiles from, https://www.mathworks.com/matlabcentral/fileexchange/35085-mat2tiles-divide-array-into-equal-sized-...
4 días ago | 0
| accepted
Calculate log multiple columns
Your code is correct, assuming Germany_Greece is a matrix and not a table or some other data type.
4 días ago | 1
| accepted
