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Walter Roberson


Last seen: Today 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 T0099119; if you are waiting on a reply from me for an older issue, please send me a reminder.

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

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Answered
Error (Unable to perform assignment because value of type 'sym' is not convertible to 'double'.)
PcT = zeros(length(thresh)); PcT is assigned as numeric zeros. F1 = int( PL(w)*f(w) * (1/(1+ U(T) * PA * B(i) * w^(-...

8 hours ago | 0

Answered
Convert series of analytical solutions to matrix vector format
syms x I E0 B l C3 C4 C5 F kt V1 = int(1/2 * I * E0 * (1 + (B-1) * x/l) * (2*C3 + 6*C4*x + 12*C5*x^2)^2, x, 0, l); V2 = int(...

8 hours ago | 0

Answered
Error using symengine Unable to convert expression containing symbolic variables into double array. Apply 'subs' function first to substitute values for
axes clear clc close all format short g ndofn = 3; % number of degrees of freedom per node % each number corresponds to a ...

8 hours ago | 1

| accepted

Answered
Error using Fseek. Invalid filer identifier, use fopen to generate a valid file identifier.
You attempt to open 45C.fid/fid but 45C.fid does not exist as a folder -- existing folder is 45temps.fid and 45meas.fid You sho...

1 day ago | 0

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Answered
How can I process all the possible pairs of arrays without using 2 nested for loops?
if all(triu(FirstMatrix) == triu(SecondMatrix), 'all')

1 day ago | 0

Answered
what is wrong on my codes ? I can not get my result any one help?
You need A = eye(6); However, A*x <= b with A = eye(6) is equivalent to x <= b which is the same thing expressed by UB, so the...

2 days ago | 0

Answered
Error using plot Vectors must be the same length.
fs=500; t=(0:(6*fs-1))/fs; sygnal2a=sin(t(1:500)*1*2*pi); sygnal2b=sin(t(1:500)*1*2*pi+2*pi); sygnal2b is the same as sygn...

2 days ago | 0

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Answered
MATLAB freeze after closing figures
This is a known problem with R2023b and Apple Silicon https://www.mathworks.com/matlabcentral/answers/710913-matlab-r2020b-free...

2 days ago | 0

Answered
How to optimise an objective function with a summation of integrals
x = lsqnonlin(@(x)(S(P,T,N,Limites_Sectores_T,x)), x0, lb, ub,[],[],Aeq, beq, options); There are a few different valid calling...

3 days ago | 0

Answered
Matrixwise subtraction yields vector - how to reshape to original logical matrix?
One way: result = arrayfun(@(IDX) mean(A(cmpMatrix(:,IDX),IDX)-B(cmpMatrix(:,IDX),IDX)), 1:size(A,2)) Chances are that this wi...

3 days ago | 1

Answered
How to import text data with different column lengths without having NaN
There is no option for producing column vectors of different lengths. After you readtable, you can newTable = varfunc(@(DATA...

3 days ago | 0

Answered
Wrong print negative number with fprintf in hex
rng(73); N = 20; r = (randn(N, 1) + 1j.*randn(N, 1)) * 10000; for i = 1:N fprintf('Real[%d] = %04X; ', i, typecast(int16...

3 days ago | 2

Answered
Solving large number of equations
syms X1 X2 X3 X4 X5 X6 X7 X8 p_11 = 1; p_12 = 2; p_13 = 3; p_14 = 4; p_15 = 5; p_16 = 6; p_17 = 7; p_21 = 8; p_22 = 9; p_23 ...

3 days ago | 0

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Answered
How to Rewrite This Section of Code as a For Loop
termAsum = 0; for term = termA(:).' termAsum = termAsum + term; end

4 days ago | 0

Answered
Running code for different variable values.
theta = 0:2:12; num_theta = length(theta); alpha = zeros(num_theta, 147); for i = 1 : num_theta this_theta = theta(i); ...

4 days ago | 0

Answered
imread file does not exist - Unable to read file with multiple images
% Specify the filename containing images foldername = 'D:\BMPtoPNG'; % Read all images from the file dinfo = dir(foldername...

4 days ago | 0

Answered
Variable q4 has an incorrect value.
syms x y g(x,y) = x*y/(x^2+y^2) dyxx = diff(diff(diff(g(x,y),y),x),x) q4 = subs(dyxx,{x,y},{1.2,3.8})

4 days ago | 0

| accepted

Answered
How do I complete my matlab code for a given formula.?
The first thing you have to do is figure out which of the two clusters corresponds to which condition. kmeans() clustering with...

4 days ago | 0

| accepted

Answered
Variable q5 must be of size [1 2]. It is currently of size [1 1]. Check where the variable is assigned a value.
syms x y f(x,y)=x-x*y^2+sqrt(y); u = sym([2,9]); part1 = u/norm(u) part2 = jacobian(f(x,y),[x,y]) q5 = dot(part1, part2) Y...

4 days ago | 0

Answered
MATLAB does not run on new iMAC
You need to deactivate on your old Mac and reactivate on your new Mac.

4 days ago | 0

Answered
Which function used to use in M-Script to remove the variables
It is not possible to create a variable with a name similar to 1Tn007 What can happen is that if you load() a .mat that was ge...

5 days ago | 0

Answered
Need Help Simplifying code
Replace pick=find(max(playerInfo(2,:))==playerInfo(2,:)); pick=pick(1); with [~, pick] =...

5 days ago | 0

| accepted

Answered
Legend according to colours of the bars
questionnaire = {'A', 'B', 'C', 'D', 'E', 'F'}; for i = 1:numel(arrays) subplot(4, 1, i); values = arrays{i}(:, 2);...

5 days ago | 0

Answered
why i got this error when i want to use GPU to accelerate the simulation?
In MATLAB R2021b, only the following are supported for GPU Coder work: Microsoft Visual C++ 2019 product family Microsoft Vis...

5 days ago | 0

| accepted

Answered
Can I create a stand-alone Windows application from my Mac that permits parallel processing?
There is no support for building for a Windows target on a Mac or Linux. ... You could potentially use Parallels.

5 days ago | 0

| accepted

Answered
Will Quality of Documentation be better in 2024 Products?
No, it will not improve in R2024a.

5 days ago | 2

Answered
I am supposed to assign a license to a colleague but I cannot find the license center.
https://www.mathworks.com/mwaccount/ is the license centre.

5 days ago | 0

Answered
Shift in lines when creating videos using VideoWriter
This is a known problem in R2023b for the Apple Silicon Possibly it only happens when you only write a single frame to the movi...

5 days ago | 0

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