Matt J

Last seen: Today | Aktiv seit 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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Beantwortet
How can I ort elements of a column in a matrix using elements of another column in another matrix
subset=[1,3] %The vector of IDs with positive y-intercept idx=ismember(Matrix1(:,3),subset); Matrix1=Matrix1(idx,:);

21 Minuten vor | 0

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solve non-linear equation
You can solve for x=e^(-z) using roots. Then use z=-log(x). Example: z=2.4; pho=2; L=2; G = exp(-z) + pho*exp(L-2*z); ...

etwa 2 Stunden vor | 0

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How to build a function fun that takes as input the matrix A and as output provides the matrix B which is produced out of A in the following ways.
You can use this FEX download, https://www.mathworks.com/matlabcentral/fileexchange/115340-block-transposition-permutation-and-...

etwa 2 Stunden vor | 0

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How to get gradient data from non-linear 2D plot
Yes, you can use the diff or gradient command.

etwa 3 Stunden vor | 0

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When plot graph vertex labels cut the edges, how to avoid it?
You can remove the node labels as follows: h=plot(graph(bucky)); h.NodeLabel={};

etwa 3 Stunden vor | 0

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How to get pixel value inside a circle
drawcircle() returns an object with a createMask method. Using the mask produced by createMask(), you can do, mean(yourImage(ma...

etwa 3 Stunden vor | 0

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Find the centre and the radius of the circle or ellipse
You can download this, https://www.mathworks.com/matlabcentral/fileexchange/87584-object-oriented-tools-for-fitting-conics-and-...

etwa 3 Stunden vor | 0

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Beantwortet
Data show one value why all values not displying?
That's not unthinkable, if the points in the plot were generated one at a time and discarded: for fid=linspace(0.01,0.1185,10) ...

etwa 5 Stunden vor | 1

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plot sfit shows an offset between data and the fit but the residuals are very small.
One thing that seems to be creating problems is that your model function returns different results depending on whether the (x,...

etwa 13 Stunden vor | 0

Beantwortet
How to append a large number of cell arrays vertically?
s=dir('stations_*.mat'); CellList=cellfun(@(z) load(z).stations1,{s.name},'uni',0); result=vertcat(CellList{:})

etwa 16 Stunden vor | 1

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Removing a part of curve
I'll demonstrate a technique using a simpler example, since only you know the mathematical meaning of the region to be excluded ...

etwa 22 Stunden vor | 0

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Get the last rows of tables inside a cell array
There is no way to avoid the slow speed of a loop when dealing with cell arrays. Cell arrays are not meant to be fast. However, ...

ein Tag vor | 0

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Why do I get 'Array indices must be positive or logical values' in symsum function?
The error is because you appear to be indexing P with a non-integer. Did you mean to write, sin(n*P*(1-y/h)) ?

ein Tag vor | 0

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Calculate the conrast by the difference between the highest and lowest intensity value
You could use medfilt2 or medfilt3 to get rid of the outliers. You could then use discretize to bin the data into bins of width ...

2 Tage vor | 0

Beantwortet
Confidence and prediction bands using nlsqcurvefit
Covariance methods are not valid when you have parameter bound constraints. Since it's not a time-consuming fit, I would just us...

2 Tage vor | 0

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Beantwortet
How to solve optimization problem using sequential minimal optimization (SMO) in MATLAB
There is this offering on the File Exchange, which I have never used, https://www.mathworks.com/matlabcentral/fileexchange/6310...

2 Tage vor | 0

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truncate at 10^-3
A few options: x=round(pi,3) y=floor(pi*1000)/1000 sprintf('%.3f',x) sprintf('%.3f',y)

3 Tage vor | 0

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Concatenate content of cells containing vectors
Simpler, yes. Faster, no. A{1,1} = 1 ; A{2,1} = 2 ; A{3,1} = [3 4 5 ]; B{1,1} = 10 ; B{2,1} = [ ]; ...

3 Tage vor | 1

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Beantwortet
Did mldivide Implementation Change in R2022b?
The condition number of clsys.A is very poor, so you should not expect any consistency in the result among different implementat...

3 Tage vor | 2

Beantwortet
Gradient function not matching array dimensions
Alternatively, why not use the gradient command? psi =rand(51); [gradx,grady]=gradient(psi); whos psi gradx grady

4 Tage vor | 0

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Beantwortet
Gradient function not matching array dimensions
The expression for the gradient is very simple. Why not just apply the analytical expression on whatever meshgrid you are workin...

4 Tage vor | 0

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This code is taking a long time to finish. I tried with vectorizing the inner loops n=2:ny-1, m=2:nx-1, but it is still slow. Should I also vectorize the time loop?
Yes, there is no reason to be doing any looping when constructing the variables predictor and corrector. They can be computed in...

4 Tage vor | 0

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Beantwortet
How do I use interp2 with mesh grid to backwards warp one image onto another to create a mosaic?
If you use imwarp instead of interp2, the OutputView setting can be used to specify where in the world coordinate system the tra...

4 Tage vor | 0

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How do I assign multiple variables the array data from multiple rows in a field
Is this what you mean? data={1,2,3,4,5,6}' [A,B,C,D,E,F]=deal(data{:})

5 Tage vor | 0

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Beantwortet
minimum value optimization of matrix with constraints
Perhaps as follows: %L=unknown parameter matrix (nxn) where A=L.'*L %Iknown=indices of known elements of A (mx1) %Aknown=kno...

6 Tage vor | 1

Beantwortet
I am trying to solve current equations of a pv cell using fsolve butit keeps showing error, can someone pls see what the error in my code is?
Perhaps as follows, V=((1:330)-1)*0.1; y=nan(size(V)); for i = 1:numel(V) fhandle = @(I) I -Is*(1-kref.^((V(i)-Vo+...

6 Tage vor | 0

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Beantwortet
All my Values not getting stored. Only my Last Value is getting stored
A loop will not accumulate a vector of results unless you tell it where in the vector the result is to be placed, e.g., for i=1...

7 Tage vor | 0

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Why does layerNormalizationLayer in Deep Learning Toolbox include T dimension into the batch?
Perhaps you can fold your T dimension into the C dimension and use a groupNormalizationLayer instead, with the groups defined so...

7 Tage vor | 0

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How to find the original vector given the outer product of the vector?
It's only possible up to a multiplicative constant of the form . n=5; psi0 = rand(n,1) + 1i * rand(n,1); outer_product = psi...

7 Tage vor | 0

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How to find out if a class is a handle class?
How can I find out if a class is a handle or a value class? You can use, isa(obj,'handle') I need a class that inherits from...

8 Tage vor | 0

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