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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^(-...

9 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(...

9 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 ...

10 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
Operands to the logical AND (&&) and OR (||) operators must be convertible to logical scalar values. Use the ANY or ALL functions to reduce operands to logical scalar values.
You would get this error if the grading system is expecting n to be a scalar but n is a 2D array instead.

4 days ago | 0

| accepted

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

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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

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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.

5 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

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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

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