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Walter Roberson


42.873 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
How to show the legends of this plot?
Record the handles of the objects you are going to produce legend() entries for. Pass those handles to legend() as the first par...

alrededor de 19 horas ago | 1

Answered
How to fix MATLAB errors arise from changing the search path?
"I usually saved my projects in C:\Program Files\MATLAB\R2016a\bin" You have corrupted MATLAB . You need to move your projects ...

alrededor de 19 horas ago | 0

Answered
How do I change the color of the markers in the legend in a scatter plot with colormap?
Most of the time, using legend() together with scatter() will not give you the results you want. The work-around is to deliber...

alrededor de 19 horas ago | 0

Answered
Leave out dot notation in table variables
The closest MATLAB equivalent is import but it only applies for packages https://www.mathworks.com/help/matlab/matlab_oop/scopin...

alrededor de 19 horas ago | 0

Answered
How to copy every 500 rows to a new variable?
result = squeeze(cellfun(@transpose, num2cell(reshape(YourMatrix.', size(YourMatrix,2), 500, []), [1 2]), 'uniform', 0)); This ...

alrededor de 19 horas ago | 0

Answered
how to take mean of every second data in a minute and an hourly?
We recommend creating timetable() and using the retime() function.

alrededor de 20 horas ago | 1

| accepted

Answered
Error: Function definitions are not permitted in this context.
It is never valid to copy and paste a "function" definition to the command line. It is also not valid to eval() a character vect...

alrededor de 20 horas ago | 0

| accepted

Answered
How can we start different sessions simultaneously?
"Is there a way to start two different sessions simultaneously?" No. And parfor or spmd will not help for this purpose. Startin...

alrededor de 21 horas ago | 0

Answered
How to remove a particular frequency in the fft code?
[~, idx] = min(abs(f - 10.1)); %which bin is closest to 10.1 ? Y(idx) = 0; %zero that bin Y(end-idx+2) = 0; %zer...

alrededor de 21 horas ago | 0

| accepted

Answered
How to Give Column Names to MATLAB Table Dynamically
Column names must be valid matlab variable names. colnames = "AD" + T; The AD can be changed to any valid prefix of a var...

alrededor de 22 horas ago | 0

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Answered
I need help ploting a graph
y=5*(1-0.5772156649.^(-x/4.8))

1 día ago | 0

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Answered
Using Textscan on non-uniform data
fid = fopen('HS_full_18md_nam_outputs.txt'); fgets(fid); %skip header ctl = fscanf(fid, '%f%f', 2); Nt = ctl(1); Ns = ctl(...

1 día ago | 1

Answered
How should I randomly generate pairs of non-identical natural numbers that should also be non-repeating?
[A, B] = ndgrid(range); mask = A==B; A(mask) = []; B(mask) = []; N = length(A); p = randperm(N, 20); pairs = [A(p); B(p)].'...

1 día ago | 0

Answered
How can I only keep keys that have the smallest value pair in a matrix?
[g, val] = findgroups(A(:,1)); B = [val, accumarray(g, A(:,2), [], @min)];

1 día ago | 0

Answered
Setpath error: the path file pathdef.m might be read only
MATLAB generally creates a writeable pathdef.m when it is installed, but not always. Sometimes pathdef.m ends up in a directory ...

1 día ago | 0

Answered
How to solve a system of two non-linear equations symbolically
sol = solve(L0 -1 +a*L1^(a-1) -a*A*L0^(a-1)==0, L1 -1 -a*L1^(a-1) +a*A*L0^(a-1)==0,'returnconditions',true); sol = stru...

1 día ago | 0

Answered
install App with image-component in older version Matlab
uiimage() cannot be used in any release before R2019a.

1 día ago | 0

Answered
What is the max image size Matlab OCR can process
"What is the largest size image Matlab's OCR can process?" 140737488355327 bytes. Call it 6 1/2 million by 6 1/2 million RGB.

1 día ago | 0

| accepted

Answered
loading excel cell in matlab
vel_data=dir('*.mat'); so vel_data contains information about .mat files WL_data=dir('*.xlsx'); so WL_data contains informati...

1 día ago | 0

Answered
How do I explain the random functions to my professor?
"Also, it will be different from picking one value each from A,B,C for 5 times compared to picking all 5 from A, then moving on ...

1 día ago | 4

Answered
What is the meaning of following code?
size(Residuals,1) is the number of rows in the Residuals array. 1:2:size(Residuals,1) is the odd-numbered rows. [1:2:size(Residu...

2 días ago | 0

Answered
I have IgorTime data in which time:units = "seconds since 1904-01-01". I would like to convert this seconds to datevc.
datetime(T/86400,'convertfrom','excel1904')

2 días ago | 1

| accepted

Answered
Need source code of this paper " Particle Swarm Optimization for Object-Based Feature Selection of VHSR Satellite Images"
https://www.mathworks.com/matlabcentral/fileexchange/56309-data-clustering-using-bat-algorithm

2 días ago | 0

Answered
Could anyone help me to display the non zero numbers with respect to each column
[A,~] = find(C); %returns column vector A = A.'; %make it into a row vector

2 días ago | 0

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Answered
What is the MATLAB function for FILTER in direct-form I?
https://www.mathworks.com/help/signal/ref/dfilt.df1.html edit(which('dfilt.df1')) Will show you the exact code that is used.

3 días ago | 0

Answered
how to extract data from the fixed-width-field format using fscanf or textscan
fileread into a character vector. regexprep to insert a space before every field. textscan the character vector.

3 días ago | 1

| accepted

Answered
Square wave with different amplitude for different time in number of cycles
250 * square(parametric_times, D) - 50 parametric_times would be such that the end of the parametric_time vector was 2*pi*numbe...

3 días ago | 0

| accepted

Answered
Concatenate Tables with one variable having different lengths
Later versions than yours reject your input syntax because of ambiguity about options versus inputs. T1 = table({'Alpha'}, 33, ...

3 días ago | 0

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Answered
Undefined function or variable 'p1x'.
Your code requires six inputs. When you click on Run, you are providing zero inputs. Where are you expecting it to get the value...

3 días ago | 0

Answered
How to convert RGB to hsv?
for H = 1:ncols if T3(H) == 0 hprime(H) = 0; elseif T1(H) == R(H) hprime(H) = mod((G(H)-B(H))/C(H), ...

3 días ago | 0

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