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Walter Roberson


42 256 total contributions since 2011

I do not do free private consulting. If you want to bring my attention to something, send a link to the MATLAB Answers location.

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Answered
Validity Student's License
The Student license does not expire. However, it is only valid while you are registered in an appropriate degree granting instit...

environ 4 heures ago | 0

Answered
Guide me what is wrong in this code,i am trying to retrieve 3 values from function and trying to place those values
The beamData Az (acceleration in the Z direction) starts out as all zero. There are no peaks in the first row, so findpeaks() re...

environ 4 heures ago | 0

| accepted

Answered
Q. Cannot display summaries of variables i.e. here Y U V with more than 524288 elements.
If you really need those statistics, then you can use min(Y(:)) max(Y(:)) mean(Y(:)) std(Y(:)) at the MATLAB command line. ...

environ 5 heures ago | 0

Answered
How to get data every second from table that has variable sampling time
Create a timetable() object and use retime()

environ 6 heures ago | 0

Answered
How to change diagnosis path in Matlab.?
That code always tries to save some files such as *-houghpara.mat files in exactly the same directory that the eye images are i...

environ 6 heures ago | 0

Answered
Image conversion to RGB
With difficulty. You would have to do something like xcorr2 in order to locate stats(K).Image within the label image. It is a l...

environ 8 heures ago | 0

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Answered
I am trying to accomplish this same task using the find() command but I'm not sure how.
Hint: t = 1:1.5:20; output = zeros(size(t)); ind = find(t >= 3 & t <= 9); output(ind) = sin(t(ind)); ind = setdiff(1:numel(...

environ 10 heures ago | 0

Answered
For live scripts, using the LaTex equations, how to represent the absolute value?
Apparently it is not easy to do "properly"; see https://tex.stackexchange.com/questions/43008/absolute-value-symbols What might...

environ 12 heures ago | 0

Answered
Is there a way to limit the "solve" function to converge only to a real solution (no imaginary or complex numbers)?
No, there is not. vpasolve() permits ranges to be specified for each value. vpasolve() will typically only find one solution Y...

environ 12 heures ago | 0

| accepted

Answered
Int gives wrong(?) answer
Not 1/2 * x * 2: it is 1/2 * x^2

environ 14 heures ago | 0

Answered
Is it possible to organize parfor outputs based on the "thread" number?
Use a parallel queue or pollable queue https://www.mathworks.com/help/parallel-computing/send.html#bvl84az-pollablequeue to send...

environ 15 heures ago | 0

Answered
If statement matching numbers
sum(ismember(user_numbers, lotto_numbers)) gives the number of matches. Around here, matching 3 only gets you a free ticket, ...

environ 19 heures ago | 0

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Answered
How to specify the location to save video using VideoWriter?
In the place you have 'MyVideo.avi' specify the directory name too in the normal way for your system.

environ 19 heures ago | 0

| accepted

Answered
How to prevent conv2d from changing image size
conv2(A, B, 'same') or conv2(A, B, 'valid')

1 jour ago | 0

| accepted

Answered
Adding new field to structure array
Not really. You could reduce by one line by using a = num2cell(arrayfun(fun, [s.f1], [s.f2])); for whatever that is worth. Yo...

1 jour ago | 1

Answered
Installing Matlab in a pen-drive
Often pen drives mount in Linux with the no execute option. Also it is not uncommon to need to sudo sh ./install My understa...

1 jour ago | 0

Answered
Which version can support the naming of m files in Chinese and the use of space naming?
On all versions, function names (and the last component of the names of .m files) can only use A-Z, a-z, 0-9, and underscore. I...

1 jour ago | 0

| accepted

Answered
Cannot find a license for distrib_computing_toolbox
Your session is configured so that your default parallel pool is on a remote system, but you do not have (an available) license ...

1 jour ago | 0

Answered
Using fprintf to output %e with one decimal point
You cannot get two digits before the decimal place in a %e format. You also cannot skip the sign after the E. Also, for large en...

1 jour ago | 0

Answered
how to know if image is rgb?
For some kinds of image files, it is not possible to be sure. You can try using imfinfo() on the image file, and looking for th...

1 jour ago | 0

Answered
How to skip the division of zero in three summation term.
syms n M N F = n-M-N; Fz = piecewise(F == 0, 0, 1/F); T = symsum( symsum( symsum( Fz, n, 1, 3), M, 1, 3), N, 1, 3)

1 jour ago | 0

| accepted

Answered
How to save matrix to .dat file in standard notation
You cannot do that using save -ascii: save -ascii uses a fixed format. Probably the easest way is filename = sprintf('output=%...

1 jour ago | 0

| accepted

Answered
I need help building a dynamically evolving matrix based on a polynomial of unknown or user inputted size.
xv = x(:); yv = y(:); X = []; deg = 0; while true X = [X, xv.^deg]; coeffs = X \ yv; residue = sum( (polyval(...

1 jour ago | 0

Answered
range2time is not working?
range2time requires the Phased Array Toolbox, R2012b or later.

1 jour ago | 0

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Answered
how can I output an option from menu after the user has selected an option
materials = {'ash', 'hicory', 'maple', 'pine'}); BatMa = menu('choose the bat material', materials); if BatMa == 0; error('can...

1 jour ago | 0

Answered
Can any one help me on this
Code is attached. I had to guess about what you were trying to do. One of your cases leaves m undefined. That case occurs for y...

1 jour ago | 1

Answered
Code for laser ablation of material
Something like initialize mass initialize velocity while velocity < target decrease mass increase velocity by force...

1 jour ago | 0

Answered
Adding Zeros vectors within a matrix
A2 = zeros(5,5); A2([1:2, 5], [1:2, 5]) = A;

1 jour ago | 2

| accepted

Answered
who to make code in gui work in any image the user input?
Same cause as for your slightly earlier and very similar posting. https://www.mathworks.com/matlabcentral/answers/457700-i-hav...

1 jour ago | 0

Answered
i have code in gui and if condition does's work why? please help me
radial basis networks are function approximations, and will seldom return exact integers -- especially since we do not know that...

1 jour ago | 0

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