Walter Roberson

Last seen: 1 dag ago | Active 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. I am currently caught up to T0099000; if you are waiting on a reply from me for an older issue, please send me a reminder.

Programming Languages:
C++, C, MATLAB, Shell, Perl, Fortran
Spoken Languages:
English

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Answered
When I export the figure, the x-axis is halved even though I have set the interval in the code.
I do not observe that? I observe a possible loss of quality, but keep in mind that the image taken includes the outside of the ...

ongeveer 14 uur ago | 0

Answered
Solving an ordinary differential equation.
Q = @(v) sym(v); h = Q(10); k = Q(60); t = Q(0.01); T0 = Q(10); T1 = Q(10); q = Q(800); syms T(x) dT = diff(T); d2T...

ongeveer 14 uur ago | 0

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Answered
clear is solwer than writing
You might be interested in the timing tests I did at https://www.mathworks.com/matlabcentral/answers/60240-what-is-the-differenc...

ongeveer 14 uur ago | 0

Answered
Solve a integral equation
Q = @(v) sym(v); syms t C real alpha = Q(2); sigma = Q(0.4); Pi = Q(pi); f(t) = exp(-(log(t)^2/(2*sigma^2)))/(t * sigma...

ongeveer 16 uur ago | 0

Answered
License Server Unsupported -5 errors
Over at https://forums.developer.nvidia.com/t/no-such-feature-exists-after-updating-our-licens/135772 I find an indication that ...

ongeveer 16 uur ago | 0

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Answered
solve a complex second order differential equation
You cannot use any numeric solver for that. You have initial conditions at η = 0, but at 0 you have a division by 0 which gets y...

ongeveer 20 uur ago | 0

Answered
Is it possible if we convert the audio that has 1 channel (mono) to 2 channel (stereo) in Matlab?
Stereo = repmat(Mono(:), 1, 2); In the case where Mono is already known to be a column vector then this can be simplified to S...

1 dag ago | 0

Answered
break function into individual variable
syms C1 C2 x y = C1*cos(2*x) - C2*sin(2*x) Y1 = children(y, 1) Y2 = children(y, 2)

1 dag ago | 0

Answered
How to display the time by a method other than the digital timer method from "duration" or "datetime"
hms() can be called passing in a duration object or a datetime object. S = seconds(finTime) ; [h, m, s] = hms(S) ;

1 dag ago | 1

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Answered
draw a 3d graph with mat function
You were not sampling finely enough, and you were also plotting outside the desired range. [X, Y] = meshgrid(linspace(0,2*pi));...

1 dag ago | 0

Answered
Saving workspace via command
save('NameOfFileToSaveTo.mat')

1 dag ago | 0

Answered
Empty sym: 0-by-1
Q = @(v) sym(v); Tc = Q(400); Pc = Q(35); R = Q(0.0821); Z = Q(0.34); syms Vc a b c; %assume([b, c], 'real') assumeAlso...

1 dag ago | 1

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Answered
How to plot an Integral
Q = @(x) sym(x); m = Q(0.023); g = Q(9.81); rho = Q(1.2); s = Q(0.00011); Cd = Q(0.9); syms v V real f =(2 .* m .* g)...

1 dag ago | 0

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Answered
how is it possible to introduce the lead value of the inputs of GA in matlab
I want to solve a multi objective problem with Genetic algorithm tool box in matleb. Note that ga() can only be used for single...

2 dagen ago | 0

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Answered
How can I run the calculation of one equation through a range of variables in one loop
S_T = 0:3:60; %row vector TGDs = sind(TS_T); %Sine of incline TGDc = cosd(TC_T); %Cosine of incline Ax = (0:0.25:5).'; %c...

2 dagen ago | 0

Answered
Alternative way of defining a variable
https://www.mathworks.com/help/optim/ug/problem-based-workflow.html Problem based optimization permits you to use optimvar() to...

2 dagen ago | 0

Answered
Please help me to look at the code. Thx
inf(3) [-1./inf (3)] If inf(3) returns a 3 x 3 array of inf, then why doesn't [-1./inf (3)] take -1 divided by a 3 x 3 array o...

2 dagen ago | 0

Answered
What should go in a next-generation MATLAB X?
As part of a discussion https://www.mathworks.com/matlabcentral/answers/1450984-what-should-go-in-a-next-generation-matlab-x#com...

3 dagen ago | 1

Answered
I am trying to calculate and plot subsonic coefficients of pressure symbolically, but it is returning a piecewise function that I can't easily plot, what am I doing wrong?
syms x ksi %N = 20; gamma = 1.4; limits = [0 1]; M = 1.2; %alpha = deg2rad([-5:1:20]); %X = linspace(0,1,N); %Geometr...

3 dagen ago | 0

Answered
error on start up
Quit MATLAB. Then rename C:\Users\Erasmus\Documents\MATLAB to C:\Users\Erasmus\Documents\old-MATLAB Now start MATLAB again; i...

3 dagen ago | 0

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Answered
problem with creat function
Your blockDecodeSyndromeMethod is trying to call DecodeSyndromeMethod with more inputs than DecodeSyndromeMethod wants. Howeve...

3 dagen ago | 0

Answered
plotting a 2-colum 2d array
That syntax of using . and then a number inside (), only works for table() objects. UIAxes = gca; A = [1, 2; 5, 6; 10, 11; 1...

3 dagen ago | 1

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Answered
Taylor series using For loop to approximate Sin(x).
SIN(-3) function y = SIN(x) %UNTITLED Summary of this function goes here % Detailed explanation goes here n ...

3 dagen ago | 0

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Answered
Check for equality in the contents of two arrays ignoring order
%sets case A = [1 3]; B = [3 1]; isequal(unique(A), unique(B)) For the sets case, a different approach just might be faster...

3 dagen ago | 0

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Answered
How to call the function based on the simulink model?
What should I modify? You should get rid of the "clear all": it is erasing variables in the base or function workspace that you...

3 dagen ago | 0

Answered
what changes are needed
filename = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/769961/G2_A.txt'; C = readmatrix(filename); forceG2...

3 dagen ago | 0

Answered
Convert cell array to excel - problem with nested cells
You have several options: write each cell entry as text, perhaps using M2s = cellfun(@mat2str, M2, 'uniform', 0) . If you do th...

4 dagen ago | 0

Answered
location information of my laptop
Not directly. However if you are using Windows then you might be able to use a .NET method such as https://docs.microsoft.com/e...

4 dagen ago | 0

Answered
How do I test a variable to see if it is empty?
Use detectImportOptions() on the file, and use setvartype() to force the columns to be double, and then readtable. When you do ...

4 dagen ago | 0

Answered
Problem running my first program
fsolve(@NL_Syst_HW4, [0,0,0]) Remember that matlab processes arguments before making the calls. The argument NL_Syst_HW4 ha...

4 dagen ago | 0

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