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Walter Roberson


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50.555 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
Fzero function error in matlab
x = fzero(@(x) (707.34/(x-x^2)*(1+0.1*(10.589*(1-x)/x).^0.75)-(x-x^2)*9778.608 , 0.2) 1 2 1 2 3 2 3 4 ...

alrededor de 13 horas ago | 0

Answered
How do I find unknown parameter from an equation?
eqn = @(c) z - a.*b./(c.*d); c = fsolve(eqn, GUESS) This assumes that the equation is complex enough that you cannot just me...

alrededor de 17 horas ago | 0

| accepted

Answered
Issues with audiorecorder function in Matlab online R2020a?
As mentioned by @Eddy Armas At least up to R2021a, MATLAB Online does not support audio input. MATLAB Online does support som...

alrededor de 17 horas ago | 0

Answered
When combining multiple photos, I want to have one matrix that shows only the highest value at each pixel's place.
Start with the first image, and copy it to the proposed output. For each additional image, figure out how it overlaps the curre...

alrededor de 18 horas ago | 0

Answered
How to increase matlabFunction length limit
matlabFunction(C, 'vars', {q, qdot, alpha, l, rho}, 'file', strcat(dpath,'/C_fun'), 'Optimize', true); Index exceeds the number...

alrededor de 18 horas ago | 0

Answered
How to make multiple execution of a code by loop ?
Replace x=array2table(x) y=array2table(y) TABLE=[A B x y]; TABLE.Properties.VariableNames(1:4) = {'A','B','x','y'}; with ...

alrededor de 18 horas ago | 0

Answered
How can I covert serious of grey scale images to jet images
in_ext = '.png'; out_ext = '.png'; projectdir = 'path/to/files'; %can be '.' outdir = 'path/to/store/output'; %must be dif...

alrededor de 18 horas ago | 0

Answered
how to speed up code
If I read the code correctly, then numused = sum(track_length_DNS); mycell_tracks_index = mat2cell(index_tracks_matching(1:num...

alrededor de 19 horas ago | 0

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Answered
Reading a .dt2 file in MATLAB
https://www.mathworks.com/matlabcentral/fileexchange/25897-read-dted-elevation-data looks like it should support .dt2 files.

alrededor de 19 horas ago | 0

Answered
Can you use matlab code within an Arduino sketch?
MATLAB code cannot be included in an arduino sketch. With current releases, you can target MATLAB code to be deployed to Raspb...

alrededor de 19 horas ago | 0

Answered
FSOLVE requires all values returned by functions to be of data type double.
syms a b c d e X=input('numb of carbon atoms in fuel'); Y=input('numb of hidrogen atoms in fuel'); Z=input('fuel to air ratio...

alrededor de 20 horas ago | 0

Answered
How to break a while loop to another one?
while outer test outer stuff quit_middle = false; while middle test middle stuff while inner test i...

alrededor de 23 horas ago | 0

Answered
Exporting the output into a .txt file
You could evalc() the code, getting back a character vector, that you then wrote to a file. You could fopen() a file, and fpri...

1 día ago | 0

Question


Identify Simulink blocks by shape and ports?
Is there a facility to help people figure out what block shapes are which Simulink / Simscape blocks? I see people posting Simu...

1 día ago | 0 answers | 0

0

answers

Answered
I'm having problems copying a 4-D array
https://www.mathworks.com/help/releases/R2017a/matlab/ref/imread.html?searchHighlight=imread&s_tid=doc_srchtitle#inputarg_idx T...

2 días ago | 1

Answered
How can I best receive data from a web hook into Matlab?
The URL for the webhook could be connected to a webserver on your host that accepted the request (such as with PHP or ASP), cons...

2 días ago | 0

| accepted

Answered
How to deal with table
Removing entries that have empty exData: mask = cellfun(@isempty, newT.exData); newT(mask,:) = []; If I understand correctly,...

2 días ago | 0

| accepted

Answered
While loop for sum
n = 1; while true do something n = n + 1; if n > N; break; end end or n = 0; while true n = n + 1; if n > ...

2 días ago | 0

| accepted

Answered
fixed points in the plots
syms A B G A, B, and G are created as scalar symbols f = matlabFunction(sum1m2, 'vars', [A, B, G]); g = matlabFunction(sum3...

2 días ago | 0

Answered
reset button gui matlab
cla RESET deletes all objects (including ones with hidden handles) and also resets all axes properties, except Position...

2 días ago | 0

Answered
Issue with lsqnonlin function solve
fix_values is a column. You subtract something from it (suppose it is a column as well), getting a column. Then you try to ^2 th...

3 días ago | 0

Answered
How to find highest and lowest numbers in vector without using build in functions?
That cannot be done. See https://www.mathworks.com/matlabcentral/answers/38787-what-can-be-programmed-without-any-built-in-funct...

3 días ago | 0

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Answered
Error: Error using dlfeval Value to differentiate must be a traced dlarray scalar.
Notice the example code has f = 100*(x(2) - x(1).^2).^2 + (1 - x(1)).^2; grad = dlgradient(f,x); so it is receiving an x (tha...

4 días ago | 1

| accepted

Answered
how to plot time-based x-axis?
numtime = 17; %or whatever timevals = linspace(0, maximum_time, numtime); arr_throughput_A = zeros(max_num_stream,numtim...

4 días ago | 0

| accepted

Answered
how to read and plot a .trc file?
The trc file you sent me is in Lecroy Binary Format. Fortunately someone has created code to read those. https://www.mathworks....

4 días ago | 0

| accepted

Answered
Calling script from a function is recommended?
% bar.m fid = fopen('baz.m', 'w'); fprintf(fid,'beta = 1:1e6;\n'); fclose(fid) whos baz(); whos clearvars foo() whos ...

4 días ago | 0

Answered
[Feature request] "Run from Start to Here" button in Live Scripts
In the Live Editor, mouse over to the white border between the line numbers and the gray space for the code. A "Run to Here" but...

4 días ago | 0

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Answered
Filter or delete data from (time)table depending of missing values
[Copying answer down from comments] Snan = @(v)sum(v) + 0/(numel(v)==6); datasum = rmmissing(retime(data, 'hourly', Snan)); (...

4 días ago | 0

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Answered
scatter3, stop the color changing after a second scatter3 command
When you use scatter3() and pass in a vector of color information, the information you pass in is not color indices into the cur...

4 días ago | 1

| accepted

Answered
using fzero to solve nonlinear equation
The function handle you pass to fzero() or to fsolve() must accept only one parameter. Your s0, vmax, and k are all known cons...

4 días ago | 0

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