
Matt J
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.
Statistics
RANK
6
of 272,978
REPUTATION
26,778
CONTRIBUTIONS
225 Questions
10,322 Answers
ANSWER ACCEPTANCE
74.67%
VOTES RECEIVED
3,506
RANK
230 of 18,438
REPUTATION
5,833
AVERAGE RATING
4.90
CONTRIBUTIONS
35 Files
DOWNLOADS
380
ALL TIME DOWNLOADS
48817
RANK
of 122,375
CONTRIBUTIONS
0 Problems
0 Solutions
SCORE
0
NUMBER OF BADGES
0
CONTRIBUTIONS
0 Posts
CONTRIBUTIONS
0 Public Channels
AVERAGE RATING
CONTRIBUTIONS
3 Highlights
AVERAGE NO. OF LIKES
2
Content Feed
How to create a Aij matrix with the commands 'for', 'function output=name_of_code' and 'imagesc'?
m=100; n=150; A=((1:m)'-(1:n)).^2; for i=1:min(m,n) A(i,i)=2*i.^2; end imagesc(A)
15 hours ago | 0
How to create a Aij matrix with the commands 'for', 'function output=name_of_code' and 'imagesc'?
I don't know how to do it and I didn't find any example. Not even here? https://www.mathworks.com/help/matlab/ref/for.html#bu...
16 hours ago | 0
Fill in values in function
Z = @(X,Y) (1.5-X+X.*Y).^2 +(2.25-X+X.*(Y.^2)).^2+(2.625-X+X.*(Y).^3).^2; Z(0,0)
16 hours ago | 1
| accepted
Parallelize nested loops with parfor
Never mind my other answer. I didn't notice that a_sim and h_sim were recursively defined. You can't avoid a loop, but you only ...
17 hours ago | 0
Parallelize nested loops with parfor
I don't think it makes sense to use any loops here at all. Just make vectorized calls to your griddedInterpolant objects. [~,~,...
17 hours ago | 0
How to interpret actual Camera Intrinsics/Principal Points results?
The uncertainty values look kind of large to me. I wonder if your 22 images are diverse enough.
17 hours ago | 0
Extracting two columns from 6-D complex double
T=table((1:numel(val))' , abs(val(:)).^2 )
23 hours ago | 0
| accepted
Effect of zero padding on FFT amplitude
When zero-padding such a signal one fundamentally change the signal from a constant-valued signal to a square-wave @Bjorn Gus...
23 hours ago | 0
How to find the closest values (positive and negative) to the line when X is zero?
load Data %Create line plot [x,is] = sort(V); y = J(is); in=find(x<0,1,'last'); ip=find(x>0,1,'first'); [xn,yn, ...
1 day ago | 0
| accepted
Objective function for fmincon from surrogate model
Can't you just do, fun=@(X) norm(mdl.predict(X)-y).^2
1 day ago | 0
| accepted
Is it possible to add more constraints than the default ones in LSQLIN function?
You can still use lsqlin, but as John said, you can add additional inequality constraints as follows, Q=-sign(d).*C; r=zeros(s...
2 days ago | 1
| accepted
Optimising Limits of Chain integrals
There is virtually no benefit to the problem based approach if you are going to use fminunc. The main advantage of problem-base...
2 days ago | 0
Cross-correlation of two complex signals using sliding dot product
If there is to be no zero-padding, what should happen when the shorter signal slides to the edge of the longer signal? Does the ...
2 days ago | 0
| accepted
Finding Roots between a Differential and Piecewise Equation
a=1; [t_root,fval]=fzero(@(t)rootFcn(t,a), pi) function out=rootFcn(t,a) xp1 =@(t) ((-(8*2)/(2^2+1))*cos(t))+((8/(2^2+...
2 days ago | 0
| accepted
Effect of zero padding on FFT amplitude
Here is an example showing that the amplitude of an FFT does not change due to zero-padding. In all cases, the peak amplitude is...
2 days ago | 0
Projection using Modified Gram-Schmidt orthogonality
Aorth=orth(A); %A orthogonalized ProjB=Aorth*(Aorth.'*B); %projection of B
2 days ago | 0
| accepted
How to use conditional bounds for parameters with lsqcurvefit?
You must divide the problem into two cases: one case where X0 is fixed at 0 and the second when Y0 is fixed at zero. xdata = 0:...
3 days ago | 3
| accepted
When using JacobianMultiplyFcn in lsqnonlin, why is Jinfo required to be numeric? How can I pass more general kinds of parameters to my JacobianMultiplyFcn?
I seem to be have been able to fool lsqnonlin into doing what I want by using the attached classdef. Still, I wonder why the Opt...
3 days ago | 0
Submitted
Tools for Processing Consecutive Repetitions in Vectors
A set of functions for labeling and manipulating groups of consecutively repeating elements in a vector.
3 days ago | 6 downloads |
How to group same value data
G=findgroups(A(:)); splitapply(@(x){x}, B(:),G)
3 days ago | 0
Latex typesetting in Livescript
I have expressed a desire to have \label{} and \ref{} in LiveScript, https://www.mathworks.com/matlabcentral/answers/1723075-au...
3 days ago | 0
calculate the euclidean distance among all the pairs of nodes and use those resulting distances as the edges weights of the graph
This is already done in spatialgraph2d() https://www.mathworks.com/matlabcentral/fileexchange/73630-spatialgraph2d which I thi...
4 days ago | 0
| accepted
Cut off a Curve created by "curve fit"
This might be what you want: for i = 1:12 x1 = [emax(i); emid(i); 0]; y1 = [vmax(i); vmid(i); dvc(i)]; p = pol...
4 days ago | 0
Question
When using JacobianMultiplyFcn in lsqnonlin, why is Jinfo required to be numeric? How can I pass more general kinds of parameters to my JacobianMultiplyFcn?
What I would like to do is use the JacobianMultiplyFcn option of lsqnonlin's trust-region-reflective algorithm where Jinfo is a...
4 days ago | 1 answer | 0
1
answerlimiting broadcast variables in parfor loops
The block decomposition that you are doing needs more explanation. If the blocks are just fixed-sized, non-overlapping tiles of ...
4 days ago | 0
how to run a function on GPU cores
so it would be great if we could have a function like "parfor" for GPU-based parallel processing. No, you cannot use GPU cores ...
4 days ago | 0
| accepted
MATLAB Problem. How to design matrix from eigenvalues
mindist=@(A) min(sqrt(pdist(real(A(:))).^2+pdist(imag(A(:))).^2)); n=5; Q=rand(n); Q(1)=0; Q=(1-eye(n)).*Q*0.5/mindist(...
5 days ago | 0
| accepted
MATLAB Problem. How to design matrix from eigenvalues
mindist=@(A) min(sqrt(pdist(real(A(:))).^2+pdist(imag(A(:))).^2)); n=5; P=rand(n); D=diag(rand(1,n)); A=P*D/P; A=A/mi...
5 days ago | 1
extract data points where the slope (derivative) of the plot changes suddenly
data=[ 1 2 3 4 3 2 1] loc=abs(diff(data,2)) > 1 loc=[false, loc ,false]; %pad with zeros because diff() shortens the vect...
5 days ago | 0
Extracting data points (with specific coordinates) from plot
For example, Y=40+0.04*linspace(-1,1,10) data=10*(1:numel(Y)) data_Extracted = data(abs(Y-40)<=0.01)
5 days ago | 0