Walter Roberson
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.
C++, C, MATLAB, Shell, Perl, Fortran
Spoken Languages:
English
Statistics
RANK
1
of 244 047
REPUTATION
116 510
CONTRIBUTIONS
34 Questions
52 695 Answers
ANSWER ACCEPTANCE
52.94%
VOTES RECEIVED
14 960
RANK
of 17 062
REPUTATION
N/A
AVERAGE RATING
0.00
CONTRIBUTIONS
0 Files
DOWNLOADS
0
ALL TIME DOWNLOADS
0
CONTRIBUTIONS
0 Posts
CONTRIBUTIONS
0 Public Channels
AVERAGE RATING
CONTRIBUTIONS
0 Highlights
AVERAGE NO. OF LIKES
Reach 100000 reputation points. Honors the first contributor to reach this milestone, Walter Roberson
Awarded to Walter Roberson on 14 Aug 2020
The contributor whose answers received the most acceptances in 2019
Awarded to Walter Roberson on 01 Jan 2020
Solve a problem for the first time
Awarded to Walter Roberson on 10 Jun 2017
Publish your first review
Awarded to Walter Roberson on 09 Oct 2019
The contributor whose answers received the most acceptances in 2018
Awarded to Walter Roberson on 18 Jan 2019
The contributor whose answers received the most acceptances in 2017
Awarded to Walter Roberson on 02 Jan 2018
Contribute at least one answer each month for 36 consecutive months
Awarded to Walter Roberson on 20 Jul 2017
The contributor whose answers received the most acceptances in 2016
Awarded to Walter Roberson on 20 Jul 2017
The contributor whose answers received the most acceptances in 2015
Awarded to Walter Roberson on 20 Jul 2017
The contributor whose answers received the most acceptances in 2011
Awarded to Walter Roberson on 20 Jul 2017
The contributor whose answers received the most acceptances in 2012
Awarded to Walter Roberson on 20 Jul 2017
The contributor whose answers received the most acceptances in 2013
Awarded to Walter Roberson on 20 Jul 2017
Content Feed
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...
environ 2 heures ago | 0
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...
environ 9 heures ago | 0
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)
environ 9 heures ago | 0
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) ;
environ 11 heures ago | 1
| accepted
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));...
environ 12 heures ago | 0
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...
environ 17 heures ago | 1
| accepted
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)...
environ 21 heures ago | 0
| accepted
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...
1 jour ago | 0
| accepted
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...
1 jour ago | 0
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...
1 jour ago | 0
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...
1 jour ago | 0
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...
2 jours ago | 1
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 jours ago | 0
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 jours ago | 0
problem with creat function
Your blockDecodeSyndromeMethod is trying to call DecodeSyndromeMethod with more inputs than DecodeSyndromeMethod wants. Howeve...
3 jours ago | 0
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 jours ago | 1
| accepted
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 jours ago | 0
| accepted
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 jours ago | 0
| accepted
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 jours ago | 0
what changes are needed
filename = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/769961/G2_A.txt'; C = readmatrix(filename); forceG2...
3 jours ago | 0
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...
3 jours ago | 0
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...
3 jours ago | 0
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 ...
3 jours ago | 0
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...
3 jours ago | 0
| accepted
How do I fix my variance? Can't figure out what wrong with my code because I keep getting NaN for my variance and y. If there anyway I could fix my variance or an easier way.
You had a persistent problem where you were assuming that var() of a vector would give you a result the same size as the vector....
3 jours ago | 0
A faster findsignal method
Maybe. It would not astonish me if parts if it could be rewritten to use an available GPU. However... the algorithm already inv...
3 jours ago | 0
How do I save the output array (y2) for each loop?
Under what circumstance could c be <= 0 such that the if would fail ? amultiple = input(sprintf('Enter multiple locations (0 - ...
3 jours ago | 0
how can I plot 3d in matlab
It would probably be easiest to just draw 3D lines using plot3() . And use grid on
4 jours ago | 0
How to loop equations and expressions used by Dynare in matlab context?
%%%%%%%%%%%%%%%%%%%%%%%%%%%% rule ={ 'a=x;' 'b=y;' "c=rho+(" + newline + ... "@ # for i in number" + n...
4 jours ago | 1
| accepted
