Community Profile # Matt J

Last seen: Today Active 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.

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lsqnonlin optimization: large condition number of Jacobian matrix at all iterations, but full rank
Your scaling isn't really doing anything meaningful, since all residuals are weighted equally. Really, you are just multiplying ...

4 hours ago | 1

Solving a complicated symbolic equation
A=3; B=9; f=@(x)A-B*x*sinh(x); [x,fval]=fzero(f,[0,10]) %first solution [x,fval]=fzero(f,[-10,0]) %second solution

5 hours ago | 1

All functions in a script must be closed with an 'end'.
Replace "return" by "end"

19 hours ago | 0

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Extract "labelhandles" from Legend
Would it be possible to get the content of the second output of the legend, i.e. "labelhandles", just by calling the first outpu...

21 hours ago | 2

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Looping scatteredInterpolant across each frame in 3D matrix
Since your grids are related by an affine warping, it might be best to use imwarp, assuming you have the appropriate toolbox.Exa...

24 hours ago | 0

How to plot a function on a user defined plane when using spherical coordinate system by specifying elevation and azimuth values at a given radial distance?
The three spherical coordinates theta, phi, and r are not enough to define the sampling of a plane. You must also define coordin...

2 days ago | 0

Calculation errors while using subs and det functions
You haven't given us access to the input variables needed to repeat the computation. However, the determinant you are evaluating...

4 days ago | 0

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Extracting from boxchart function the median, quartiles, and whisker data.
I don't believe those quantitites are directly available as permanent property data. When you position the cursor over one of th...

4 days ago | 1

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How to define the order of layers/plots and axes?
1) Hfig=figure('Visible','off); p(1) = plot(...); p(2) = scatter(...). p(3) = line(..); p(4) = fill(...), p(5) = imagesc(...) ...

4 days ago | 0

error in the process of symbol operation of the matrix
Nothing is wrong with T, though possibly you didn't scroll down far enough to see the definitions of all the sigmas.

4 days ago | 0

Is it possible to handle a slider with an 'on-line' update? I mean, updating the value continously during the sliding.
Yes, use the ValueCHangingFcn callback https://www.mathworks.com/help/matlab/ref/uislider.html#buicpgg-1_sep_shared-ValueChangi...

5 days ago | 0

How to extract rows of data according to text containing specific words in cells in Matlab
copepods= contains(C.object_id,"cruise2012") & ... contains(C.object_annotation_hierarchy,"Copepoda");

6 days ago | 0

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lsqcurvefit does not follow convergence criteria in summation.
After the fit has converged (but not giving a useful result) I checked for the convergence criterion and it wasn't replaced with...

6 days ago | 0

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Unrecognized function or variable 'x0'.
Relocate the last 2 lines from newmintafun1 and make x0 the correct length. x0 = [10; 6; 4; 3; 4; 3; 2; 3; 18; 7; 25; 10; 5; 5;...

6 days ago | 0

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How to create big matrix that the item is small matrix
See, How to Generate a Block Toeplitz Matrix. Then replace the last D block with F, Matrix(end-11:end,end-11:end)=F;

6 days ago | 0

Fit gaussian surface on 3D data
Using gaussfitn from, https://www.mathworks.com/matlabcentral/fileexchange/69116-gaussfitn load Image %cropped to include onl...

6 days ago | 1

Question

Why does isequal() return false when the reloaded handle is compared to the original handle, in the code below. h=plot(1:5); s...

7 days ago | 2 answers | 0

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Solve linear equation in matrix form with least square method
If I use (A.'*A)\(A.'*b), i can get the result An even easier and more accurate way to get it is, x=A\b and that is the meth...

7 days ago | 0

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Interpreting the results of 'fsolve'
It means fsolve thinks it found a solution. Whether you can "trust" the solution is an open-ended question. It depends on the ap...

8 days ago | 0

using matchpairs when objects have different capacities
Then you are not seeking pairings. Therefore, matchpairs will not apply. But you can probably use minL1intlin from this FEX down...

8 days ago | 0

Coding volume segmentation with multiple thresholds (CT data)
I can iterate through different CT number thresholds, using a function to create a binary mask (a 3D matrix) at each. However, I...

9 days ago | 0

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Attempt to grow array along ambiguous dimension
In this line, idealF1(distance4 <= D01)=0; you have not checked the size of distance4 and of idealF1.

9 days ago | 0

want to plot ellipses with different a and b values in x^2/a^2 + y^2/b^2 = 1 in Matlab 3d plot
Simplie enough. a=0.1;b=0.15; fsurf(@(x,y) x.^2/a^2+y.^2/b^2) ;

9 days ago | 0

How do I fit two data sets to each other?
Sounds like a 1D image registration problem. Maybe consider imregtform.

10 days ago | 0

Trying to do an if/and statement on a vector but have an addition apply to only one element of vector
I think a better method would be to update the compass position incrementally, using the attached file cumangle.m t=linspace(-1...

10 days ago | 0

generate all variations on a 20-mer, that are 1 to 4 mismatches away

10 days ago | 0

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How can I make the numeric edit field blank?
You can set the ValueDisplayFormat property to %0.0d

11 days ago | 1

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