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
multiple colorbars in one figure
You can create multiple colorbar() using the 'Position' property. If colorbar() believes that a new colorbar overlaps an existin...

31 minutes ago | 0

Answered
Using an anonymous function handle as input into another function handle
Your premise is incorrect. The below example shows that it is valid to pass function handles between multiple levels omega = @(...

1 hour ago | 0

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use the 'patch' function with different results (using different matrices)
In your first patch() call you ask for 'k' -- black -- for the faces. The edge colors default to black as well. In the second p...

1 hour ago | 0

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How to test if equation in .p file is linear.
In some cases you might get lucky, in that if you pass purely symbolic variables to the function, you might get back a formula. ...

2 hours ago | 1

Answered
Isosurface plots appear 2d when used with subplot
MATLAB has divides graphics calls into "high level" and "low level". "High level" calls check whether hold is on, and if not...

24 hours ago | 1

Answered
Problems with savepath in R2023b
On a shared system, users should not have write access to pathdef.m inside the MATLAB installation directory. If this is not a ...

1 day ago | 1

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I'm trying to make a for loop that has if statments that use the increments from my i to run them. How can I make this work, it won't run.
if i==0:99 The right-hand side of that == is a vector containing [0, 1, 2, 3, ... 99] The == is comparing the current valu...

1 day ago | 0

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Using lsqnonlin and getting the message Error line 218.
clear all; clc; close all L=[3,3,3]; %starting point of electrode's position LEb=zeros(1,1); for xa...

1 day ago | 0

Answered
Algorithm 1. Set time step (increment) 2. set max number of time steps 3. start with ground values of temperature at x=0, y=0, z=0, theta=0, and a particular value of fi 4. co
Remember that comments extend to the end of the physical line, not to the next semi-colon, so your comment about "Initialize var...

1 day ago | 0

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How do I use single precision numbers in a summation? My result is not coming out as expected.
You are not doing repeated addition. Repeated addition is not the same as multiplication. Also, a and b are scalar, so a*b is a...

1 day ago | 0

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Answered
I can not run my function file for zohplot
When you attempt to run a function by pressing the green Run button, MATLAB never, I repeat never searches the calling environme...

1 day ago | 0

Answered
How to Find Duplicate Entries and give popup message in the 50 different Edit Field in MATLAB App Designer ?
[groupnum, group_content] = findgroups(app.YourGUITable.Data.Period); if numel(groupnum) == height(app.YourGUITTable.Data) ...

1 day ago | 0

Answered
Number of values stored are more than the ratio of stop Time/Step size ?
See https://www.mathworks.com/help/simulink/ug/choose-a-solver.html and https://www.mathworks.com/help/simulink/ug/managing-samp...

3 days ago | 1

Answered
Error 2, 753 when trying to activate key
First off: if you were installing the license server facilities, then the resulting MATLAB would not need to be activated -- bec...

3 days ago | 0

Answered
error to assign string in field struct's
Compare: Sis(73).Slipp = 'example'; [Sis.SlippSource] = testfun(); function output = testfun() output = 123; end

3 days ago | 1

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Answered
Licence manager changes / Activate and manage devices
Notice that the "Option" field is "Total HeadCount". The implication is that the license is not an individual license -- the "Ma...

3 days ago | 0

Answered
ascribe zeros to an array
frequencies = linspace(0, 2400, 250); spectrum = rand(size(frequencies)); subplot(2,1,1); plot(frequencies, spectrum); title...

3 days ago | 0

Answered
How can I resolve the error in output for a WSN simulation in MATLAB
endToEndDelay = endToEndDelay + (t - transmissionTimes(node)); You never reset endToEndDelay, so it becomes unclear...

3 days ago | 0

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Answered
how to use vpasolve to solve the equation sin(x)==0 in the range of (0,5] instead of [0,5]?
vpasolve() does not support open or semi-open intervals. The trick is to use syms x sol = vpasolve(sin(x)==0, x, [1e-63 5]) ...

3 days ago | 0

Answered
Subs returns empty sym n-by-0
subs(expr,sol) If sol is a struct output of solve() with returnparameters but there were no auxiliary variables introduced ...

3 days ago | 0

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Iterate through a matrix to find specific entry
Reminder: length is defined as: 0 if any dimension of the array is 0 max() of the dimensions of the array otherwise You appea...

4 days ago | 0

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Strange limitations on script files?
Not allowing function definitions in the middle of a script file removes ambiguity about whether code after a function definitio...

4 days ago | 0

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Why is triplequad not recommended? In my case it works better than integral3
triplequad invokes dblquad which invokes quad . Because quad() requires that the limits are finite, then dlbquad() and triplequ...

4 days ago | 0

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What is a simple way to check if a collection of vectors all have the same number of elements
a = rand(3,1); b = rand(3,1); c = rand(4,1); d = rand(3,1); vecs = {a,b,c,d}; n = cellfun(@numel,vecs,'uniform',0); if...

4 days ago | 0

Answered
Why isn't my code iterating more than once?
r1_real=me(1,K); r2_real=me(2,K); b1_real=me(3,K); b2_real=me(4,K); Those are all scalars. x=(r1_real(1,K).^2-r2_real(1,K)....

5 days ago | 0

Question

convert patch structure to graph() object?
Is there an easier / better way to convert a patch() faces / vertices structure to a graph object? %Where S is a struct with fa...

5 days ago | 2 answers | 0

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answers

Answered
how to set y-axis as log scale?
The best way to create that type of axes is to use the semilogy function. Alternatively, you can set the ‘YScale’ property on th...

5 days ago | 51

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Answered
calculate volume from iso-surface coordinates (x,y,z).
If you use boundary then it has an optional second output which is the volume. However, I would not expect boundary() to be abl...

5 days ago | 1

Answered
Accepting multiple values for a function. I want my function to accept multiple values for beta
U(1,[4 5]) = [ alpha-beta, beta ]; when beta is a vector, then you have a problem: you need different 5 x 5 U matrices for each...

5 days ago | 0

Answered
The function textscan is problematic and has serious bug!
You coded if totalNumFigureBad == totalNumFigureGood disp('The textscan is problematic!'); end and if counterBad == cou...

5 days ago | 0