Walter Roberson
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50,541 total contributions since 2011I 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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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...
5 hours ago | 1
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...
5 hours ago | 0
How to deal with table
Removing entries that have empty exData: mask = cellfun(@isempty, newT.exData); newT(mask,:) = []; If I understand correctly,...
5 hours ago | 0
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 > ...
5 hours ago | 0
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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...
8 hours ago | 0
reset button gui matlab
cla RESET deletes all objects (including ones with hidden handles) and also resets all axes properties, except Position...
8 hours ago | 0
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...
22 hours ago | 0
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...
1 day ago | 0
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...
1 day ago | 0
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...
2 days ago | 0
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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....
2 days ago | 0
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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 ...
2 days ago | 0
[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...
2 days ago | 0
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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)); (...
2 days ago | 0
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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...
2 days ago | 1
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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...
2 days ago | 0
filtering data from table
Close. TQTable = timetable(Time, Temperatuur, GlobalStraling);
2 days ago | 0
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minor grid in consecutive plots
grid minor toggles the visibility of the minor grid lines. Minor grid lines lie between the tick marks. Not all types of charts ...
2 days ago | 0
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loading a sequence of datasets using parfor
You need to synchronize with the GPU, and spend time transfering data to it, and wait for it to be ready, and read the data back...
2 days ago | 0
Unable to perform assignment because the left and right sides have a different number of elements.
S = zeros(1,T/dt); S(1) = N; S is a vector. dS = ((-beta*(B/(B+k))*S(tt) + ub*(S(tt)+I(tt)+R(tt)) - ud*S) * dt)'; ...
2 days ago | 0
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How to find and store each spot center position in the loop.
Use bw = bwareafilt(imbinarize(croppedImage), [10 inf]); Some of your images end up with very small extra regions, jus...
2 days ago | 0
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Plot time series data colored by color coded by ID
t = readtable('YourFile.csv'); [G, ID] = findgroups(t{:,1}); hold on h = splitapply(@plot, t{:,2}, t{:,3}, G); xlim auto; yl...
2 days ago | 0
Switching between functions that have the same name
You do not need to restoredefaultpath but you do need to remove the previous folder You do, however, need to clear the class. ...
2 days ago | 0
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How to stretch cos fit
axes([0 0.75 0.75 1.03]); %must do this before plot h(1) = scatter(xData, yData, 'b+', 'DisplayName', 'data'); hold on h(2)...
2 days ago | 0
subplot for 'controlchart' function
Use the 'parent' option ax(1) = subplot(2,1,1); plot(ax(1), rand(1,20)); ax(2) = subplot(2,1,2); load parts st = contro...
2 days ago | 1
Why symvar() sort 10 smaller than 9
symvar() sorts inconsistently if I recall correctly. It gets complicated when you start mixing numbers and underscores. For the...
2 days ago | 0
How to use else if with ODE45 solver?
The mathematics used in the RK methods such as ode45(), require that for any one call the function be continuous and its first t...
2 days ago | 0
How to avoid rounding error
A = [sym(10)^(-20) 1 ; 1 2] [L,U] = lu(A) L*U - A You can see from this that in order to get back A exactly, then you need a ...
2 days ago | 0
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How to achieve identical timing of two side by side annotations
For anything like this you should probably be using the third party Psychtoolbox http://psychtoolbox.org/
2 days ago | 0
How to use movefile correct?
files = dir('/Users/haron/Desktop/Work/Haron/aprikose_edfs/*.edf.html'); for ii=1:length(files) oldname = fullfile(files(...
3 days ago | 0
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