Mainly retired from Eastman Kodak. (Of course, Kodak itself is now semi-retired. I don't think I had any influence in that.) I still write MATLAB code as I find something interesting, and I do attempt to write new tools to put on the File Exchange when I think I can make a contribution.

However, I DON'T answer direct e-mail questions, and I do NOT do homework. In general, your homework is YOUR problem, not mine. Please do NOT e-mail me with your homework problems or student projects. If I was willing to answer your questions, I would very rapidly become overwhelmed, because one question is never just one simple question.

When I'm not doing something with MATLAB, you might find me playing bridge, either in the club or online on BBO.

Professional Interests: MATLAB, numerical analysis, mathematical modeling

Avocational interests: Bridge, woodworking, woodturning

Answered

When using alpha shape and the alpha radius is not specified. How does MATLAB obtain it? I want to understand it.

I don't have access to the code, so I can only surmise (since I've written alpha shape codes before in MATLAB, but not the one i...

When using alpha shape and the alpha radius is not specified. How does MATLAB obtain it? I want to understand it.

I don't have access to the code, so I can only surmise (since I've written alpha shape codes before in MATLAB, but not the one i...

10 hours ago | 0

Answered

intermediate exponential calculation goes to infinity

Calc 101. An integral is a linear operator. You can move any multiplicative constant inside or outside of the integral. Suppos...

intermediate exponential calculation goes to infinity

Calc 101. An integral is a linear operator. You can move any multiplicative constant inside or outside of the integral. Suppos...

16 hours ago | 0

Answered

Generate beta random number without statistics toolbox

As a followup, I note that the answer by dpb seems to be incorrect. There are several ways to generate a beta random variable. ...

Generate beta random number without statistics toolbox

As a followup, I note that the answer by dpb seems to be incorrect. There are several ways to generate a beta random variable. ...

1 day ago | 0

Answered

Symbolic solver yields wrong solution

It seems a subtle thing. We need to "branch" out from our preconceptions. ;-) pretty(solutions) / 0 \ | | | -p ...

Symbolic solver yields wrong solution

It seems a subtle thing. We need to "branch" out from our preconceptions. ;-) pretty(solutions) / 0 \ | | | -p ...

2 days ago | 4

Answered

How do I explain the random functions to my professor?

I wonder if your professor needs to learn a few things. For starters, that Minitab is not doing anything any better than is MATL...

How do I explain the random functions to my professor?

I wonder if your professor needs to learn a few things. For starters, that Minitab is not doing anything any better than is MATL...

3 days ago | 5

| accepted

Answered

How to fit a curve to a step function?

ALWAYS plot everything. Do that before you do anything else. plot(xavg_40s1,havg_40s1,'.') grid on So your data looks like ...

How to fit a curve to a step function?

ALWAYS plot everything. Do that before you do anything else. plot(xavg_40s1,havg_40s1,'.') grid on So your data looks like ...

3 days ago | 3

| accepted

Answered

Not enough input arguments

What is the purpose of that line? Lets see... help square 'square' requires Signal Processing Toolbox. So, assuming that you ...

Not enough input arguments

What is the purpose of that line? Lets see... help square 'square' requires Signal Processing Toolbox. So, assuming that you ...

3 days ago | 0

Answered

NAN from griddata for scatteredInterpolant

Your problem is that you have no idea how to use those tools. There is no need to use griddata AFTER you used scatteredInterpola...

NAN from griddata for scatteredInterpolant

Your problem is that you have no idea how to use those tools. There is no need to use griddata AFTER you used scatteredInterpola...

3 days ago | 0

Answered

Graphing two parametric functions in terms of x

You got exactly the correct thing. You just need to look carefully at the y axis labels on the two plots. Just add this line af...

Graphing two parametric functions in terms of x

You got exactly the correct thing. You just need to look carefully at the y axis labels on the two plots. Just add this line af...

3 days ago | 0

| accepted

Answered

Are there any plans to add support in exportONNXNetwork tool for the maxUnpooling2dLayer?

Sorry, but surely not possible to tell you. MathWorks does not discuss their plans for the future on this forum. Anyone who doe...

Are there any plans to add support in exportONNXNetwork tool for the maxUnpooling2dLayer?

Sorry, but surely not possible to tell you. MathWorks does not discuss their plans for the future on this forum. Anyone who doe...

4 days ago | 0

Answered

creating a curve from XYZ points (centreline) and then split curve into new points

This is a simple problem of interpolation, except that you don't know how to do the interpolation. Standard tools like interp1 d...

creating a curve from XYZ points (centreline) and then split curve into new points

This is a simple problem of interpolation, except that you don't know how to do the interpolation. Standard tools like interp1 d...

4 days ago | 1

Answered

Matlab Crushes when new .m file is added

This is not a crash, nor even a crush. It is just that MATLAB caches the files in the MATLAB directories. It does this to enhanc...

Matlab Crushes when new .m file is added

This is not a crash, nor even a crush. It is just that MATLAB caches the files in the MATLAB directories. It does this to enhanc...

4 days ago | 0

| accepted

Answered

dot product for complex vector

help dot dot Vector dot product. C = dot(A,B) returns the scalar product of the vectors A and B. A and B must be ve...

dot product for complex vector

help dot dot Vector dot product. C = dot(A,B) returns the scalar product of the vectors A and B. A and B must be ve...

4 days ago | 0

| accepted

Answered

i need to switch all integers in my array to positive numbers

You might need to read the getting started tutorials, if you are asking questions this basic. help abs

i need to switch all integers in my array to positive numbers

You might need to read the getting started tutorials, if you are asking questions this basic. help abs

5 days ago | 0

Answered

large numbers in K means

x = rand(1048575,1); size(x) ans = 1048575 1 [IDX, C] = kmeans(x, 10); C Warning: Failed to converge...

large numbers in K means

x = rand(1048575,1); size(x) ans = 1048575 1 [IDX, C] = kmeans(x, 10); C Warning: Failed to converge...

5 days ago | 0

Answered

Expression of interpolating function

A high order interpolating polynomial is a REALLY, REALLY, REALLY bad idea. There, if i said it three times, it must be true. Se...

Expression of interpolating function

A high order interpolating polynomial is a REALLY, REALLY, REALLY bad idea. There, if i said it three times, it must be true. Se...

5 days ago | 0

Answered

In-Situ Combustion Model - MATLAB code

This is a simple error of syntax, which seems a bit strange for someone who has written such a long code to misunderstand. You s...

In-Situ Combustion Model - MATLAB code

This is a simple error of syntax, which seems a bit strange for someone who has written such a long code to misunderstand. You s...

5 days ago | 1

| accepted

Answered

H is a 108x108 tall array, P is a 108x9 double array, when excute etu=H\P , this syntax is wrong, what is right ?

Why would you use tall on a problem that tiny? Anyway, you could just convert to double. In fact, that proves you do not seem to...

H is a 108x108 tall array, P is a 108x9 double array, when excute etu=H\P , this syntax is wrong, what is right ?

Why would you use tall on a problem that tiny? Anyway, you could just convert to double. In fact, that proves you do not seem to...

6 days ago | 0

Answered

Generate Random Matrix 0's,1's

Easy enough. matno = 10; % the number of random possiblities rows=10; columns=3; Now we want to create a matrix of size (row...

Generate Random Matrix 0's,1's

Easy enough. matno = 10; % the number of random possiblities rows=10; columns=3; Now we want to create a matrix of size (row...

7 days ago | 1

| accepted

Answered

How do I extract 3D matrix from 5D matrix

What does it mean to extract a specific matrix? p = 1; z = 1; A = D(:,:,:,p,z); is a matrix of the desired size, extracting...

How do I extract 3D matrix from 5D matrix

What does it mean to extract a specific matrix? p = 1; z = 1; A = D(:,:,:,p,z); is a matrix of the desired size, extracting...

8 days ago | 2

| accepted

Answered

Sparse Matrix with Non-positive Indices

What you say makes no sense. If you have a full matrix already, and you are turning that into a sparse matrix, then you would ju...

Sparse Matrix with Non-positive Indices

What you say makes no sense. If you have a full matrix already, and you are turning that into a sparse matrix, then you would ju...

9 days ago | 1

Answered

Problem optimizing anonymous function using fzero

There is no need to use symbolic tools to solve problems via fzero, merely understanding how to use functions. However, your que...

Problem optimizing anonymous function using fzero

There is no need to use symbolic tools to solve problems via fzero, merely understanding how to use functions. However, your que...

10 days ago | 1

Answered

error using Solve with inequality

You did not follow the example carefully. syms x >> S = solve(x^2 - 4*x + 3 < 0,'returnconditions',true) S = struct with ...

error using Solve with inequality

You did not follow the example carefully. syms x >> S = solve(x^2 - 4*x + 3 < 0,'returnconditions',true) S = struct with ...

10 days ago | 1

| accepted

Answered

Obtain eigenvalue from matrix and known eigenvector

The simple answer, as long as the vector x IS an eigenvector. is just: val = norm(A*x)/norm(x); You should see that this is no...

Obtain eigenvalue from matrix and known eigenvector

The simple answer, as long as the vector x IS an eigenvector. is just: val = norm(A*x)/norm(x); You should see that this is no...

10 days ago | 0

| accepted

Answered

fsolve doesn't give correct answer even with close initial guess

A serious issue is that you use many numbers accurate to only 2 decimal digits. So even though you may think the answer is corre...

fsolve doesn't give correct answer even with close initial guess

A serious issue is that you use many numbers accurate to only 2 decimal digits. So even though you may think the answer is corre...

11 days ago | 0

| accepted

Answered

nonlinear curve fitting a function on data

sin(theta) is not a variable name. beta = 1.135e-4; sintheta = [-0.81704 -0.67649 -0.83137 -0.73468 -0.66744 -0.43602 0.45368 ...

nonlinear curve fitting a function on data

sin(theta) is not a variable name. beta = 1.135e-4; sintheta = [-0.81704 -0.67649 -0.83137 -0.73468 -0.66744 -0.43602 0.45368 ...

11 days ago | 1

| accepted

Answered

I have 30x30 matrix and need to extrapolate lower triangle numbers

You just want to extract the lower triangle, whatever is in it? The result going into a vector? A = magic(5) - 10 A = 7 ...

I have 30x30 matrix and need to extrapolate lower triangle numbers

You just want to extract the lower triangle, whatever is in it? The result going into a vector? A = magic(5) - 10 A = 7 ...

13 days ago | 0

| accepted

Answered

Solve for a system of equations

This is not actually a question about MATLAB. Why would you assume that every set of complicated nonlinear equations has an exp...

Solve for a system of equations

This is not actually a question about MATLAB. Why would you assume that every set of complicated nonlinear equations has an exp...

13 days ago | 0

Answered

Matrix Division: Different sized matrices

Is there a reason why you have not read the getting started tutorials? The manual is always a good thing to read. C = A./B; ...

Matrix Division: Different sized matrices

Is there a reason why you have not read the getting started tutorials? The manual is always a good thing to read. C = A./B; ...

13 days ago | 2