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Walter Roberson


Last seen: Today
46.805 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
merging date and time columns in a timetable
tt = table2timetable( YourTable, 'RowTimes', datetime(YourTable.Date) + duration(YourTable.Time) );

etwa 11 Stunden ago | 0

Answered
Error while Diagonalizing the Matrix
Do not use P^(-1), which is also known as inv(P), if you can avoid doing so. The calculations have too much numeric difficulty. ...

etwa 11 Stunden ago | 0

Answered
Downloading text files from Matlab causes them to be corrupted
Don't use Notepad. Use Notepad++ or any editor created in the last 20 years. Notepad is so old it is only able to properly handl...

etwa 13 Stunden ago | 0

| accepted

Answered
Don't simplify while using 'latex'
In some of the earlier releases, it was possible to ask to, for example, latex('3*x - 5*x') It would not be unreasonable to wa...

etwa 14 Stunden ago | 0

| accepted

Answered
Not got the ordered student suite license
Today is a holiday in the USA; it might be a few days before your order is processed.

etwa 15 Stunden ago | 0

| accepted

Answered
fast fourier tranform gives unequals amplitudes for frequencies with initially (before the fft) the same amplitude
sin(2*pi*(900*10^-9)^-1*t) (900*10^-9)^-1 is 1111111.11111111 Hz. But your sampling frequency is 32768. You have about 33.9 cyc...

etwa 16 Stunden ago | 0

Answered
How to create an underline in text
https://www.mathworks.com/matlabcentral/answers/95028-how-can-i-create-a-latex-table-from-a-matlab-array shows the latex code ...

etwa 17 Stunden ago | 2

Answered
Is an infinite for loop infinite?
No, if you use for i=1:inf then MATLAB will stop after 9223372036854775806 iterations. That number is 2^63 - 2 On my system,...

ein Tag ago | 1

Answered
A year containing a date or not
year = 2050; month = 1; has_sunday30 = weekday(datetime(year, month, 30)) == 1;

ein Tag ago | 0

Answered
Undefined function or variable in my simple project
Your code only has alamatfile as a local variable to btnBrowse_Callback . You are not saving it for use in other functions. htt...

ein Tag ago | 0

| accepted

Answered
Size mismatch (size [1 x 11] ~= size [1 x 10]).
i=2:length(z), That is 2:10 j=1:length(z), That is 1:10, which is one element longer than i. D(i-1)+D(j) D(i-1) becomes D(1...

ein Tag ago | 0

| accepted

Answered
How to generate one random integer
The following generates integers natively. typecast(randi([0 255],1,8,'uint8'),'int64') The range is all possible integers bet...

ein Tag ago | 0

Answered
Help Needed for the following coding problem
z1_dot(:,i) = gamma*(1-z1(:,i))-kp*sumz1(:,i)+ki*sumw1(:,i); Those create numeric values that will be effectively constants aft...

ein Tag ago | 0

Answered
I keep getting a warning that says polynomial is badly conditioned when I use polyfit() to find the polynomial.
If your x values range from 0 to 2000, then you cannot numerically justify a degree 10 polynomial fit. Consider that for x = 1, ...

ein Tag ago | 0

Answered
imagesc funtion axes configuration
xlim([0 50]); xticks(0:5:50); %ticks at 0, 5, 10, 15, and so on Warning: none of your image x data is as low as 50...

ein Tag ago | 0

Answered
Convert Fortran code to Matlab
1 FORM='UNFORMATTED',ACCESS='DIRECT', There is no standard for the representation of DIRECT UNFORMATTED files in fortran. The m...

ein Tag ago | 0

| accepted

Answered
How to matlab display matrix in different way
To display as an image on the screen, then you can do things like for K = 1 : 3; text(0.25*K, 0.5, string(B(:,K))); end If you...

ein Tag ago | 0

Answered
getting error about wrong input argument
smote('C:\Users\Haleema\Desktop\skin matlab\orignal', 8, [327,514,1099,115,1113,6705,142]) Not a cell array of numeric values, ...

ein Tag ago | 0

| accepted

Answered
a matrix with a dirac delta function
Guessing: for j = 1:n + 1 u_approx_dirac(:,j) = u_approx(:,j) .* dirac(x - c - j*delta); end

ein Tag ago | 0

Answered
Variable TempData must be of size [25 33]. It is currently of size [31 24]. Check where the variable is assigned a value.
You cannot do that. After reducing by 1 row, your data ended up with 31 rows. Therefore it had 32 rows to start. After reducin...

ein Tag ago | 0

| accepted

Answered
Multiplying Matrices not working
Final = (GradesDat)*distribution.';

ein Tag ago | 0

Answered
Why is image colored instead of white?
You are comparing component by component. You are not testing whether any of the RGB components for a pixel are greater than zer...

2 Tage ago | 0

| accepted

Answered
error in using latin hypercube sampling 'lhsnorm'
When your mu is a vector of length 4, then your cov must be a 4 x 4 positive definite (covariance) matrix, not a row vector.

2 Tage ago | 0

| accepted

Answered
For Loop using xlsread indexing
basenames = {'Red' 'Green' 'Orange' 'Purple' 'Pink'}; nbase = length(basenames); raw = cell(nbase, 1); for K = 1 : nbase ...

2 Tage ago | 0

| accepted

Answered
How do I create a table that I don't now the size of ahead of time?
https://www.mathworks.com/help/matlab/matlab_prog/add-and-delete-table-rows.html

2 Tage ago | 0

Answered
Convert a cell array using str2double
C={'9, 1., 0.514999986' '10, 0., 0.514999986' '11, 1., 0.75' '12, 0., ...

2 Tage ago | 0

| accepted

Answered
How to delete the text of the previous state
function pushbutton2_Callback(hObject, eventdata, handles) [UElocation] = textread('observe/mdUELocationforGUI2.txt'); InputUE...

2 Tage ago | 1

| accepted

Answered
how to upload file type text and number in excel on uitable gui matlab
I already showed you that in https://www.mathworks.com/matlabcentral/answers/557590-data-string-unreadable-in-uitable-matlab#com...

2 Tage ago | 0

Answered
Nested loop error and saving result
You start i = 0. You do not increment i until after you store a value. So the first time through, you are storing into results(0...

2 Tage ago | 0

| accepted

Answered
discretize two arrays into 50x50 grid
N = 50; x_values = [71.2413900000000, 71.2336100000000, 71.2825000000000, 70.9786100000000, 69.1533400000000] y_va...

2 Tage ago | 0

| accepted

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