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

Reshape: Math lesson help

Your matrix is 5x50. You need to understand how the elements lie in sequence in memory. MATLAB stores each column in sequence. ...

Reshape: Math lesson help

Your matrix is 5x50. You need to understand how the elements lie in sequence in memory. MATLAB stores each column in sequence. ...

10 hours ago | 0

Answered

spline interpolation image way to connect ?

Your problem is you have a vague idea of what you wanted to do. But you got it completely wrong. Absolutely, completely, so. Yo...

spline interpolation image way to connect ?

Your problem is you have a vague idea of what you wanted to do. But you got it completely wrong. Absolutely, completely, so. Yo...

21 hours ago | 2

| accepted

Answered

what is the best method to fit a curve to strain-stress data?

NO polynomial will ever fit that curve (at least, not fit it well.) NONE. PERIOD. x = data_mathwork(:,1); >> y = data_mathwor...

what is the best method to fit a curve to strain-stress data?

NO polynomial will ever fit that curve (at least, not fit it well.) NONE. PERIOD. x = data_mathwork(:,1); >> y = data_mathwor...

1 day ago | 1

| accepted

Answered

Solving for 4 unknowns

Why do these not look like actual solutions to the equation system? subs(eq1,{L,V,x1,y1},[1.86, 0.29, 0.537, 0.258]) ans = 0 ...

Solving for 4 unknowns

Why do these not look like actual solutions to the equation system? subs(eq1,{L,V,x1,y1},[1.86, 0.29, 0.537, 0.258]) ans = 0 ...

1 day ago | 0

| accepted

Answered

Write a function to show a square “random” image. The function will take in “at least” one input argument which is the size of the image in pixels. As a default, the image will be shown in black-white. If a second input argument is provided, it will

Your problem is that you misunderstand nargin. By way of example, I wrote this very simple function. function week7hw1(pixels,...

Write a function to show a square “random” image. The function will take in “at least” one input argument which is the size of the image in pixels. As a default, the image will be shown in black-white. If a second input argument is provided, it will

Your problem is that you misunderstand nargin. By way of example, I wrote this very simple function. function week7hw1(pixels,...

2 days ago | 0

| accepted

Answered

64 bit binary number representation in matlab without rounding off

Maybe you are looking for something like this. I wrote a little utility recently that fully extracts the binary form of any nume...

64 bit binary number representation in matlab without rounding off

Maybe you are looking for something like this. I wrote a little utility recently that fully extracts the binary form of any nume...

2 days ago | 1

Answered

Why are all the examples for matlab functions hindered by useless simplistic examples that do not show how all features of the functions work? One cannot determine how to use any function of any complexity with the examples given.

As someone who has written dozens of toolboxes, with literally hundreds of functions, and someone who tends to be a manical perf...

Why are all the examples for matlab functions hindered by useless simplistic examples that do not show how all features of the functions work? One cannot determine how to use any function of any complexity with the examples given.

As someone who has written dozens of toolboxes, with literally hundreds of functions, and someone who tends to be a manical perf...

3 days ago | 3

| accepted

Answered

Fminsearchbnd vs. Pattern Search vs. Surrogate Optimzation to attempt to find the global optimal solution.

Each solver has what is called basins of attraction for each local solution. If you start the solver off in any point in one of ...

Fminsearchbnd vs. Pattern Search vs. Surrogate Optimzation to attempt to find the global optimal solution.

Each solver has what is called basins of attraction for each local solution. If you start the solver off in any point in one of ...

4 days ago | 2

| accepted

Answered

Random assignments through the use of a MatLab programmed Calender

This is not really a MATLAB question, because it is just programming, something you could do in any language at least in theory....

Random assignments through the use of a MatLab programmed Calender

This is not really a MATLAB question, because it is just programming, something you could do in any language at least in theory....

4 days ago | 0

Answered

sparse matrix operations to gain efficiency

Are those matrices mostly zero? No. It looks like they are 50% zeros. Sparse will not gain anything, because thre is also overhe...

sparse matrix operations to gain efficiency

Are those matrices mostly zero? No. It looks like they are 50% zeros. Sparse will not gain anything, because thre is also overhe...

7 days ago | 0

| accepted

Answered

How does function std process complex numbers

std uses the formula that is given by David, which is just the standard fornula, with no difference for complex inputs. But just...

How does function std process complex numbers

std uses the formula that is given by David, which is just the standard fornula, with no difference for complex inputs. But just...

8 days ago | 0

Answered

I need help in this question please?

What are you trying to do with the lines: syms B assume(B>1) Which have nothing to do with the problem? It looks like they a...

I need help in this question please?

What are you trying to do with the lines: syms B assume(B>1) Which have nothing to do with the problem? It looks like they a...

8 days ago | 2

Answered

how to apply cubic spline interpolation curve fitting

What I think you do not understand is those curves are noisy, and you do not understand splines. The curves you drew are not noi...

how to apply cubic spline interpolation curve fitting

What I think you do not understand is those curves are noisy, and you do not understand splines. The curves you drew are not noi...

9 days ago | 0

| accepted

Answered

please explain diag([rand(1,n-2) + 1, 1, 17])

When you have a problem, take it apart from the inside. What is inside-most? Was diag called with multiple inputs at all? (No.) ...

please explain diag([rand(1,n-2) + 1, 1, 17])

When you have a problem, take it apart from the inside. What is inside-most? Was diag called with multiple inputs at all? (No.) ...

10 days ago | 2

| accepted

Answered

How can I calculate the slope of third order polynomial fit

Is there a reason why you would not think to differentiate it? help polyder

How can I calculate the slope of third order polynomial fit

Is there a reason why you would not think to differentiate it? help polyder

11 days ago | 0

Answered

Symbol calculation and numerical values

You are doing things in the wrong order. k,e,m,w are not unknowns. They are knowns. So why have you set them up as symbolic? N...

Symbol calculation and numerical values

You are doing things in the wrong order. k,e,m,w are not unknowns. They are knowns. So why have you set them up as symbolic? N...

11 days ago | 0

| accepted

Answered

How to construct a weighed 2D histogram?

Just use accumarray to sum the weights in each bin.

How to construct a weighed 2D histogram?

Just use accumarray to sum the weights in each bin.

11 days ago | 0

Answered

How can I convert red curve in an image into a line ?

What does it mean to convert something into a "curve"? In fact, there is no need to do anything of the sort. You have a picture...

How can I convert red curve in an image into a line ?

What does it mean to convert something into a "curve"? In fact, there is no need to do anything of the sort. You have a picture...

12 days ago | 1

| accepted

Answered

Sine curve fit to data with an unknown dc offset

Of course it is possible. Use the curve fitting toolbox. ft = fittype('a + b*sin((x - c)/d)','indep','x'); mdl = fit(X(:),Y(...

Sine curve fit to data with an unknown dc offset

Of course it is possible. Use the curve fitting toolbox. ft = fittype('a + b*sin((x - c)/d)','indep','x'); mdl = fit(X(:),Y(...

13 days ago | 0

| accepted

Answered

How can I check if a variable exists within another variable?

It fails, because exist does not apply to fields of a strcture. help isfield isfield True if field is in structure array.

How can I check if a variable exists within another variable?

It fails, because exist does not apply to fields of a strcture. help isfield isfield True if field is in structure array.

15 days ago | 0

Answered

random numbers without repetition of two consecutive numbers

These things are far easier than you think. In fact, there are (at least) two simple ways to solve it. Generate multiple sets ...

random numbers without repetition of two consecutive numbers

These things are far easier than you think. In fact, there are (at least) two simple ways to solve it. Generate multiple sets ...

15 days ago | 4

Answered

im not able to run below given code

Now that we know what the problem is, those functions are part of the Phased Array System toolbox. https://www.mathworks.com/he...

im not able to run below given code

Now that we know what the problem is, those functions are part of the Phased Array System toolbox. https://www.mathworks.com/he...

16 days ago | 0

Answered

alpha shape vs convex hull volume value

A problem with your data is it has holes in it. The inside looks to be empty. But worse, it has a void on one corner, where the ...

alpha shape vs convex hull volume value

A problem with your data is it has holes in it. The inside looks to be empty. But worse, it has a void on one corner, where the ...

18 days ago | 2

| accepted

Answered

Rank of Symbolic Matrix returns incorrectly

"Concuded by inspection." I've gotta laugh at that. B = [ 1, -1, -1, ...

Rank of Symbolic Matrix returns incorrectly

"Concuded by inspection." I've gotta laugh at that. B = [ 1, -1, -1, ...

20 days ago | 1

Answered

Interpolating from set of vectors to another with some tolerance?

Confusing as hell. You have one set of values as a pair of vectors, (xfine_i,Tfine_i). As well, you have the same thing at a c...

Interpolating from set of vectors to another with some tolerance?

Confusing as hell. You have one set of values as a pair of vectors, (xfine_i,Tfine_i). As well, you have the same thing at a c...

20 days ago | 0

| accepted

Answered

construc matrix D by OD process?

I suppose I'll make this an answer instead of just a comment, since nobody has answered yet. If all you wanted is to construct ...

construc matrix D by OD process?

I suppose I'll make this an answer instead of just a comment, since nobody has answered yet. If all you wanted is to construct ...

20 days ago | 1

| accepted

Answered

Solving trigonometric equation using "solve" function.

Whats the problem? There is no need to set any properties anyway on such a trivial problem. syms x; x = solve(230.769*cos(x)+1...

Solving trigonometric equation using "solve" function.

Whats the problem? There is no need to set any properties anyway on such a trivial problem. syms x; x = solve(230.769*cos(x)+1...

21 days ago | 0

| accepted

Answered

how to create a symmetric binary variable matrix

You need to learn to index matrices, as you have been posting repeatedly what are virtually the same questions. Fundamentally, w...

how to create a symmetric binary variable matrix

You need to learn to index matrices, as you have been posting repeatedly what are virtually the same questions. Fundamentally, w...

23 days ago | 0

| accepted

Answered

Display numbers as power of N in a symbolic expression?

I don't think you can, at least, not easily. You can do pretty much anything with sufficient effort of course. syms X expr = e...

Display numbers as power of N in a symbolic expression?

I don't think you can, at least, not easily. You can do pretty much anything with sufficient effort of course. syms X expr = e...

24 days ago | 1

| accepted

Answered

ode45 varargin - additional arguments after options

Long ago and far away, in an age long since past, MATLAB did not have function handles. There were no anonymous functions. There...

ode45 varargin - additional arguments after options

Long ago and far away, in an age long since past, MATLAB did not have function handles. There were no anonymous functions. There...

25 days ago | 0

| accepted