5,433 total contributions 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.

Answered

Why is det(x) better than rcond(x) in determining non-singularity here?

rcond is telling you how easy it is to invert a set of linear equations based on x. det() does not give you that kind of inform...

Why is det(x) better than rcond(x) in determining non-singularity here?

rcond is telling you how easy it is to invert a set of linear equations based on x. det() does not give you that kind of inform...

약 6시간 ago | 1

Answered

Constraining fit to two-variable function

My question is, how do I constrain the fit so that H(r,eta) does not go above 1? Polynomials cannot be bounded everywhere. You ...

Constraining fit to two-variable function

My question is, how do I constrain the fit so that H(r,eta) does not go above 1? Polynomials cannot be bounded everywhere. You ...

약 7시간 ago | 1

| accepted

Answered

inconsistent linear system of equation

You can find the least squares solution to a linear system of equation A*x=b using backslash x_leastsquares = A\b

inconsistent linear system of equation

You can find the least squares solution to a linear system of equation A*x=b using backslash x_leastsquares = A\b

1일 ago | 0

Answered

find first line that satisfies condition; skip next few; then find next line that satisfies condition

idx = diff([0;TTL_column(:)>4.8])>0; TTL_column(idx) = 10000;

find first line that satisfies condition; skip next few; then find next line that satisfies condition

idx = diff([0;TTL_column(:)>4.8])>0; TTL_column(idx) = 10000;

1일 ago | 0

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Answered

how to solve many polynomial equations listed in a matrix?

Here's a method withoutt loops, [a,b,c]=deal(A(:,1),A(:,2),A(:3)); D=sqrt(b.^2-4.*a.*c); I=[-b-D, -b+D]./(2.*a);

how to solve many polynomial equations listed in a matrix?

Here's a method withoutt loops, [a,b,c]=deal(A(:,1),A(:,2),A(:3)); D=sqrt(b.^2-4.*a.*c); I=[-b-D, -b+D]./(2.*a);

1일 ago | 0

Answered

Generating a matrix based on an equation with conditions

For example, >> A=zeros(10,1); A(1:5)=4; A(6:10)=3 A = 4 4 4 4 4 3 3 3 ...

Generating a matrix based on an equation with conditions

For example, >> A=zeros(10,1); A(1:5)=4; A(6:10)=3 A = 4 4 4 4 4 3 3 3 ...

3일 ago | 1

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Answered

Create an accurate boundary around 2D point cloud horizontal plane

You can use alphaShape.

Create an accurate boundary around 2D point cloud horizontal plane

You can use alphaShape.

3일 ago | 0

Answered

Interpolating a 3D Matrix using interp1

Using my KronProd class (Download) m=14; p=221; A = rand(m,m,p) ; M=40; %new XY dimension B=interp1(eye(m),linspace(1,m,M),...

Interpolating a 3D Matrix using interp1

Using my KronProd class (Download) m=14; p=221; A = rand(m,m,p) ; M=40; %new XY dimension B=interp1(eye(m),linspace(1,m,M),...

4일 ago | 0

Answered

Can I use Optimization tool like fmincon or ga etc if I have constraint optimization problem that optimization variable cannot be within a range inside upper and lower limit?

Example : suppose I am solving an optimization problem where x should be within 1 and 10 or 29 and 99. The feasible space for x...

Can I use Optimization tool like fmincon or ga etc if I have constraint optimization problem that optimization variable cannot be within a range inside upper and lower limit?

Example : suppose I am solving an optimization problem where x should be within 1 and 10 or 29 and 99. The feasible space for x...

4일 ago | 0

| accepted

Answered

Finding a pixel location after imrotate

Well, the center of the image in your example is at c=[512.5;340]; and the rotation matrix expressing the rotation is R=[cosd...

Finding a pixel location after imrotate

Well, the center of the image in your example is at c=[512.5;340]; and the rotation matrix expressing the rotation is R=[cosd...

4일 ago | 1

| accepted

Answered

Adding constraints to lsq fitting

Any chance you could modify the code without the weighting function and with the new data? Note that this means rdf_contact and ...

Adding constraints to lsq fitting

Any chance you could modify the code without the weighting function and with the new data? Note that this means rdf_contact and ...

4일 ago | 0

Answered

Adding constraints to lsq fitting

Here is an adaptation of the algebraic solution that I presented in your previous thread. I don't bother with the lsqcurvefit a...

Adding constraints to lsq fitting

Here is an adaptation of the algebraic solution that I presented in your previous thread. I don't bother with the lsqcurvefit a...

5일 ago | 2

Answered

initlalize several variables at once

Just to sum things up here, below is my implementation of the fit, combining all my various recommendations. Both the algebraic ...

initlalize several variables at once

Just to sum things up here, below is my implementation of the fit, combining all my various recommendations. Both the algebraic ...

5일 ago | 1

Answered

initlalize several variables at once

One other thing I would point out is the model function you have shown us here is linear in the coefficients. This means that it...

initlalize several variables at once

One other thing I would point out is the model function you have shown us here is linear in the coefficients. This means that it...

5일 ago | 1

Answered

How to automatically constrain some of the unknown values in an optimization problem?

I will assume you have some binary vector v which indicates the groupings of the variables, so for example this, [0 0 x(1) x(2)...

How to automatically constrain some of the unknown values in an optimization problem?

I will assume you have some binary vector v which indicates the groupings of the variables, so for example this, [0 0 x(1) x(2)...

6일 ago | 1

Answered

initlalize several variables at once

Is there a way to more easily set this, assuming they all have the same initial guess? One way: params0=linspace(0.1,0.1,13) ...

initlalize several variables at once

Is there a way to more easily set this, assuming they all have the same initial guess? One way: params0=linspace(0.1,0.1,13) ...

6일 ago | 1

Answered

initlalize several variables at once

If all you're trying to do is polynomial surface fits of various orders, I would just use the Curve Fitting Toolbox, if you have...

initlalize several variables at once

If all you're trying to do is polynomial surface fits of various orders, I would just use the Curve Fitting Toolbox, if you have...

6일 ago | 1

| accepted

Answered

Replace part of matrix with other matrix.

Z=zeros(2); B=B+cell2mat({Z,A,A1;A2,Z,A3;A,A1,Z})

Replace part of matrix with other matrix.

Z=zeros(2); B=B+cell2mat({Z,A,A1;A2,Z,A3;A,A1,Z})

6일 ago | 1

| accepted

Answered

General Approach to Fitting dozens of curves using the same coefficients

You can use lsqcurvefit to do so, simply by posing the problem as a 30-parameter fit. If you do this, you will want to provide a...

General Approach to Fitting dozens of curves using the same coefficients

You can use lsqcurvefit to do so, simply by posing the problem as a 30-parameter fit. If you do this, you will want to provide a...

7일 ago | 1

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Answered

Placing values in a matrix with values from another matrix

A(A==1)=B;

Placing values in a matrix with values from another matrix

A(A==1)=B;

7일 ago | 0

| accepted

Answered

Number of elements error

for i = 3:(length(x)-2) ff(i) = (-1*x(i+2)+6*x(i+1)-3*x(i)-2*x(i-1))/(6*dx); L = L + dx*((f(x(...

Number of elements error

for i = 3:(length(x)-2) ff(i) = (-1*x(i+2)+6*x(i+1)-3*x(i)-2*x(i-1))/(6*dx); L = L + dx*((f(x(...

7일 ago | 0

| accepted

Answered

Removing sub matrix from 3d matrix, if any values in the matrix exceed a certain min/max value

discard=any( any( epochs_CG(1:2, :, :)>=100 ,2) ,1); epochs_CG(:,:,discard)=[];

Removing sub matrix from 3d matrix, if any values in the matrix exceed a certain min/max value

discard=any( any( epochs_CG(1:2, :, :)>=100 ,2) ,1); epochs_CG(:,:,discard)=[];

7일 ago | 0

| accepted

Answered

How to replace 2x2 zero sub matrices by different 2x2 matrices ?

basically i want solution in this form x p1 p2 p3 p1 x p2 p3 p1 p2 x p3 p1 p2 p3 x C={zeros(2), p1,p2,p3}; result=B+ce...

How to replace 2x2 zero sub matrices by different 2x2 matrices ?

basically i want solution in this form x p1 p2 p3 p1 x p2 p3 p1 p2 x p3 p1 p2 p3 x C={zeros(2), p1,p2,p3}; result=B+ce...

7일 ago | 0

| accepted

Answered

How to replace 2x2 zero sub matrices by different 2x2 matrices ?

Here is a simple example, but the right hand side can be any array with an appropriate number of elements B(B==0)=1:48;

How to replace 2x2 zero sub matrices by different 2x2 matrices ?

Here is a simple example, but the right hand side can be any array with an appropriate number of elements B(B==0)=1:48;

7일 ago | 0

Answered

Plotting subplot with two concurrent plots

figure; for k = 1:5 subplot(2,5,k); [val,loca]=(max(abs(squeeze(S(1,k,:,:))))); plot(T,squeeze(abs(S(1,k,92,:))),T,squeeze...

Plotting subplot with two concurrent plots

figure; for k = 1:5 subplot(2,5,k); [val,loca]=(max(abs(squeeze(S(1,k,:,:))))); plot(T,squeeze(abs(S(1,k,92,:))),T,squeeze...

7일 ago | 0

| accepted

Answered

How to use blkdiag command to create a matrix such that its diagonal blocks are random 2 x 2 matrices?

Acell=mat2cell(rand(8,2), ones(1,4)*2,2) B=blkdiag(Acell{:})

How to use blkdiag command to create a matrix such that its diagonal blocks are random 2 x 2 matrices?

Acell=mat2cell(rand(8,2), ones(1,4)*2,2) B=blkdiag(Acell{:})

7일 ago | 0

| accepted

Answered

Not quite fitting the data using lsqcurvefit

When your model function is fully vectorized, as suggested by Walter, the results are better, but only you can know for sure wha...

Not quite fitting the data using lsqcurvefit

When your model function is fully vectorized, as suggested by Walter, the results are better, but only you can know for sure wha...

8일 ago | 0

| accepted

Answered

Defining array contents - order doesn't matter - Linear programming problem

It does not matter what order the B(i) are in, as long as the ordering of the rows A(i,;) matches B(i).

Defining array contents - order doesn't matter - Linear programming problem

It does not matter what order the B(i) are in, as long as the ordering of the rows A(i,;) matches B(i).

10일 ago | 0