# Walter Roberson

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.

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**Content Feed**

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

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

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

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

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

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

How i can input values from user in array

consider an editable uitable().

circa 14 ore ago | 0

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

extracting rows from large table

mask = YourTable{:, 5} == 0; subset0 = YourTable(mask, :);

circa 22 ore ago | 0

| accepted

Access Sub-fields of multiple different-named fields in struct

struct2cell(structfun(@(F)F.x, s, 'UniformOutput', 0))

circa 22 ore ago | 1

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

Find the position of numbers in array

percent_present = mean(ismember(SmallVector, LargeVector)) * 100

1 giorno ago | 0

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

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

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

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

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

Retrieve data from a guidata from another file

handles_hf = guidata(hf); if handles_hf.X.Value == 1

1 giorno ago | 0

| accepted

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

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

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

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

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

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

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

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

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

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

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

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