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Walter Roberson


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49.278 total contributions 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.

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Answered
Why am I getting the Not enough Space error on install?
https://www.mathworks.com/matlabcentral/answers/388570-how-can-i-change-the-temp-directory-the-matlab-installer-uses#answer_3102...

circa un'ora ago | 0

Answered
How to find a decimal point value and to stop at the first value
[eigvects,~,eigvals] = pca(D); cumulative_percent_variance_permode = 100*eigvals/sum(eigvals); test = cumsum(cumulative_percen...

circa un'ora ago | 1

| accepted

Answered
How to compare greek letters if they are same
Typically the easiest way to handle situations like this, that are not plain upper / lower case (use upper() or lower() or strcm...

circa un'ora ago | 0

Answered
Error in importing the matlab ouput to excel file
syms N Qo = xlsread('suspended.xlsx','A:A'); R = xlsread('suspended.xlsx','B:B'); No = xlsread('suspended.xlsx','C:C'); X ...

circa 3 ore ago | 0

Answered
matlab 2021-a
March 18th, 2021 at 19:11 Eastern time.

circa 5 ore ago | 0

| accepted

Answered
Anomaly with comments and rating in one file in File Exchange.
That is a new contribution that you are confusing with the related contribution https://www.mathworks.com/matlabcentral/filee...

1 giorno ago | 0

| accepted

Answered
The following error occurred converting from sym to double: Unable to convert expression into double array.
You initialized X_T to numeric (such as double precision), either explicitly or else that you happened to have a numeric one sit...

1 giorno ago | 1

Answered
empty sym: 0-by-1 for Simultaneous equation
You are trying to solve 8 equations for 6 variables, but they are not consistent for all 8 equations. syms a b c d e x equ1 = ...

1 giorno ago | 1

Answered
calculating an integral of complex function substituting data from excel
format long g e = [2.90234, 2.90343, 2.98021]; x = 3.01; k = 8.62*10^-5; T = 160; a = 0.2; fun = @(x,k,T,a,b,e) exp(-b.^...

1 giorno ago | 0

Answered
How can I create a 2D contour Plot from X,Y,Z table?
num=50; Lpmax=700e-6; Lpmin=20e-6; Lr=2.77e-3; Cr=2.5e-9; f=1/(2*pi*sqrt(Lr*Cr*0.5)); ...

1 giorno ago | 0

Answered
convert dd/mm/yyyy ro serial
d = readmatrix('excel.xlsx', 'D9:D7808'); d.Format = 'yyyy-MM-dd'; And if you need to, cellstr(d)

1 giorno ago | 0

Answered
for loop return empty struct
syms x y z thickness = 0.1:0.01:0.30; unitcellsize = 1:0.1:6; num = max(size(unitcellsize)); step = 0.5; a = 0:step:unitc...

1 giorno ago | 0

Answered
Selection months (winter) in a matrix
maxyear_to_calculate = 32; winter = permute(wind(:,:,[12,1,2],:), [3 1 2 4]); %month, long, lat, year nyear = size(winter,4...

1 giorno ago | 0

| accepted

Answered
How to open an excel file in read-only with actxserver?
https://excel.officetuts.net/en/vba/open-workbook-as-read-only https://www.mathworks.com/matlabcentral/answers/306813-problem-...

1 giorno ago | 0

| accepted

Answered
match time stamps index
v1 = [1610759986514 1610759986549 1610759986583 1610759986618 ] v2 = [1610759986540 1610759986589] interp1(v1, 1:length(v1), v...

1 giorno ago | 0

Answered
xlswrite error; not working entirely or throwing up an error
Your variable Sample is empty, so when you construct filename = [RawImages '\' Sample '\' Sample] you are getting the result ...

1 giorno ago | 0

| accepted

Answered
How to change the date-format of an existing file ?
datetime('15-März-2019', 'Locale', 'de') So use readcell() with 'Locale', 'de'

1 giorno ago | 0

Answered
Array indices must be positive integers or logical values.
derivative_x(a)=2*kons_G*rho_model*t*(-(1/(z2((x(a)-x0)^2/z2^2+1)))+(1/(z1((x(a)-x0))^2/z1^2+1))); %sudah dalam mGal MATLAB ...

1 giorno ago | 1

| accepted

Answered
Input files editing format
fid = fopen('input.txt', 'r'); nodedata = cell2mat( textscan(fid, '%*f,%f,%f', 'CommentStyle', {'*Heading', '*Node'}) ); e...

1 giorno ago | 0

| accepted

Answered
findpeaks [pks, locs] cannot detect NaN
if u ~= 0 Your u is a vector. The condition will be considered true only if all the entries are true, which is to say the same ...

2 giorni ago | 0

Answered
where is the mistake?
What is being integrated? What is the lower bound? What is the upper bound? Your use of [-20 20 0 2] suggests that you are exp...

2 giorni ago | 1

| accepted

Answered
Multiple inputs using dialog box then inputs are placed into equation to get an output?
sigma_bw = str2double(P_bw) ./ (str2double(h_bw) .* str2double(L_bw));

2 giorni ago | 0

Answered
Trying to use Symbolic Math Toolbox to prepare to solve two coupled second order ODEs
After edditing the ftotal to include the (t) for the Force functions Not a good idea. A = 0.1; w = 3; X_1 = 15; X_2 = 5;...

2 giorni ago | 0

| accepted

Answered
Comparing 2 Data sets (with different lenght)
No. The problem is not well defined. What could make the problem well defined is if there were time measurements associated wit...

2 giorni ago | 0

Answered
Why do I get the Error: Array indices must be positive integers or logical values.
l starts at as 0. (notice you even coded it as being floating point rather than integer!) The assignment to help does not chang...

2 giorni ago | 1

| accepted

Answered
"Call the path to this directory <"Example"> "How to call a path?
That is a descriptive narrative. You installed MatConvNet somewhere . It does not need to be installed to any particular locat...

2 giorni ago | 0

| accepted

Answered
Reading Specific Columns of File
data = readmatrix('TheFileNameGoesHere.txt'); student_number = data(:,1); exam_1 = data(:,2); However you should consider ins...

2 giorni ago | 0

Answered
How to make the keyboard keys on the computer unable to be used to input the Matlab GUI calculator.
you could create one radio button for each different value that you wanted to represent you could create one push button for ea...

3 giorni ago | 0

| accepted

Answered
How to change color in Graph (jet)
% Define domain dx = 0.001; L = pi; x = (-1+dx:dx:1)*L; n = length(x); nquart = floor(n/4); % Define function f = x; h1 =...

3 giorni ago | 0

| accepted

Answered
Matlab does not plot the function
GH_num= [1 2 3]; GH_den= [4 5 6 7 8]; GH_w=[]; wvals = 2*pi*logspace(-1,3,1000); %NEW for w = wvals ...

3 giorni ago | 0

| accepted

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