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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
how to simplify a symmatrix expression
syms MW0 [3 3] matrix syms MDW0 [3 3] matrix syms Cn [3 3] matrix expression = Cn*(MW0+ MDW0) - Cn*MW0 class(expression...

circa 6 ore ago | 1

Answered
Check what values of three variables fulfill a certain condition
You do not need to loop over z. Instead, take z = sqrt(x.^2+y.^2) and test to see whether z is an integer. And... vectorize. Fo...

circa 6 ore ago | 0

Answered
Gauss Elimination - making my upper triangular matrix
length(b) of a 2D array is defined as length = 0 if isempty(b) length = max(size(b)) otherwise You should avoid using length(...

circa 6 ore ago | 0

| accepted

Answered
Graphing partial sums of harmonic fourier series
Use x = linspace(-2, 4, 200); Currently you are using x = [-2, -1, 0, 1, 2, 3, 4] which is not enough to get a decent graph.

circa 8 ore ago | 0

Answered
Comparing difference between two tables
If you mean that they are table() objects, then you cannot index a table object using only a single subscript. You can, however,...

circa 8 ore ago | 0

Answered
what does this line of do
FV might be a structure that has a field named totalArea and the content of the field is to be copied to a destination. Or po...

circa 9 ore ago | 0

Answered
How i can input values from user in array
consider an editable uitable().

circa 14 ore ago | 0

Answered
i am receiving the error "Execution of script loopRectangular as a function is not supported" when i try to run the following line of code: ha=loopRectangular('Length',1.0,'W
It sounds as if the function is defined inside the mlx and you are trying to call it from outside the mlx. That is not possible....

circa 15 ore ago | 0

Answered
extracting rows from large table
mask = YourTable{:, 5} == 0; subset0 = YourTable(mask, :);

circa 22 ore ago | 0

| accepted

Answered
Access Sub-fields of multiple different-named fields in struct
struct2cell(structfun(@(F)F.x, s, 'UniformOutput', 0))

circa 22 ore ago | 1

Answered
Why does sqlread() not work?
https://www.mathworks.com/help/database/ug/sqlite.sqlread.html sqlread() for sqllite() requires r2022a or later; you are usin...

circa 23 ore ago | 0

Answered
Find the position of numbers in array
percent_present = mean(ismember(SmallVector, LargeVector)) * 100

1 giorno ago | 0

Answered
The source code for the parfor-loop could not be found
Sometimes you need to addAttachedFiles; https://www.mathworks.com/help/parallel-computing/parallel.pool.addattachedfiles.html

1 giorno ago | 0

Answered
create a function from temperature data
If you have the Curve Fitting Toolbox, you can use curvefitter() https://www.mathworks.com/help/curvefit/curvefitter-app.html . ...

1 giorno ago | 0

Answered
How to fill just such successive elements in row of matrix?
Consider for example, A(i : min(i+k-1, end), j) This would refer to at most k consecutive rows starting at row i but would sto...

1 giorno ago | 0

Answered
Extracting envelope using hilbert transform
According to the documentation, the real part of the return value is the same as the input value, and the hilbert transform is s...

1 giorno ago | 1

Answered
How to put bounds and delete certain rows from a matrix.
In MATLAB, if you use logical indexing to delete entries from an array, then the result you get is a column vector in linear ind...

1 giorno ago | 0

Answered
Retrieve data from a guidata from another file
handles_hf = guidata(hf); if handles_hf.X.Value == 1

1 giorno ago | 0

| accepted

Answered
Calculate the area of geometry
The first thing you need to do is decide how the user is going to represent the specific shape for calculation purposes. are y...

1 giorno ago | 0

Answered
How to distribute random points outwards from a center location?
cx = 3; cy = 5; %as appropriate R = 20; N = 1000; theta = rand(1, N) * (2 * pi); rbase = rand(1,N) * R; [X, Y] = pol2cart...

1 giorno ago | 0

Answered
Problem using variable='z^-1' in Z transform with Z^-1 format
Setting the Variable property afterwards just changes the Variable property, without reinterpretting the matrices. It is not a c...

1 giorno ago | 0

Answered
MAJOR 25+ YEAR OLD MATLAB BUG. PLEASE, PLEASE FIX! Ctrl-C doesn't work, no way to stop a process.
| appreciate that there are issues with OS implementations, eg memory management, that make this a challenge. That said, I'm qu...

1 giorno ago | 1

Answered
got new laptop; can't access matlab from it
https://www.mathworks.com/downloads/ for downloads. You will probably need to deactivate against the old system to activate on ...

1 giorno ago | 0

Answered
Has anyone got aaS Matlab toolbox I need it soon kindly help I will be very grateful to you
The current student software downloads are linked from https://www.ansys.com/academic/students Ansys aaS appears, however, to ...

1 giorno ago | 0

Answered
find 1s in the Matrix
firstcol = 48; lastcol = 65; offsetcol = 14; idx = firstcol:lastcol; offsetidx = idx-offsetcol; result = YourMatrix(:,offse...

1 giorno ago | 0

| accepted

Answered
Drawing a boundary box around an image?
My goal is to create a bounding box around the non-zero pixel value region of my image. filename = 'https://www.mathworks.com...

1 giorno ago | 0

| accepted

Answered
Poisson distribution and discrete distribution
fitdist allows you to fit a distribution to data. I want to fit Y to a Discrete distribution There are an infinite number of d...

1 giorno ago | 0

Answered
creating a function nonpivotcols that takes a m*n matrix as input and produces a matrix consisting of the nonpivot columns of the input
[R pcols]=rref(A); A(:,pcols)=[]; You deleted the pivot columns out of A. Whatever is left must be non-pivot columns. [r,fcol...

1 giorno ago | 0

Answered
What does it mean to "% extract t and h(t) for time range 5.0<=t<=12.0" when "h=4.0+6.0*t*10^-0.5-(4*10^-0.25)*cos(0.75*pi*t)"?; when
One way: Loop over the indices of the vector of t. At each point, make the "current" t equal to the t vector indexed at the cur...

2 giorni ago | 0

Answered
Select multiple radiobutton at the same time
hf=exemple; You run the code in exemple and it returns. You are no longer running any code inside exemple but it set up sev...

2 giorni ago | 0

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