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
Why I am getting "Matrix is singular to working precision"?
The equations have an infinite number of solutions. They are consistent but the 4th equation can be deduced from the previous 3....

5 hours ago | 0

Answered
Matlab R2021a quit.
The code was attempting to use the third party package refprop version 9.0 or 8.1, which was for 2013 to 2016. The mex file used...

5 hours ago | 0

Answered
Unexpected behavior in classdefs that inherit from handle
This is documented. https://www.mathworks.com/help/matlab/matlab_oop/initialize-property-values.html#brqy3km-10 MATLAB evalua...

12 hours ago | 1

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Answered
Help me plot the solution in graph
A = randi([-9,9]) B = randi([-9,9]) C = randi([-9,9]) fun1 = @(x,y) A*x + B*y + C A2 = randi([-9,9]) B2 = randi([-9,9]) C2...

13 hours ago | 0

Answered
error when plotting 3 first order differential equations
syms x; You created x as a scalar symbolic variable. soln = ode45(@Problem03ODEFunction,[0 10],[0;0;0]); You calculate the so...

14 hours ago | 0

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Answered
Index exceeds the number of array elements (1).
format long g h = rand() %guess L = rand() * 3 %guess F = sort(rand(1,7)) %guess a = rand(size(F)) %guess b = ran...

16 hours ago | 0

Answered
processing a file but keeping blank lines intact
ConstantOffset = as appropriate; filename_in = 'as appropriate'; filename_out = 'as appropriate preferably not the same'; ...

16 hours ago | 0

Answered
How to keep the values for particular dimension of a matrix and rest of the dimension will be zeros?
Easy way: B = zeros(size(A), 'like', A); B(350:400,20:35) = A(350:400,20:35); Now B is A with all the other elements zeroed. ...

1 day ago | 0

Answered
I am confused on why I am getting huge numbers at the values 0,75,150, and 300 in my code
Algebraically, b should be 0 at 0, 150, 300 (but not 75), and division by 0 gives infinity. In the below plot, you do not see th...

1 day ago | 1

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Answered
How to prevent unwanted line breaks when using sgtitle function in figure?
pt_blk is a cell array so pt_blk(si) is a cell array. ['Pt: ', {'429-040 vs 041'}, ', Contact:'] Alternately, pt_blk might be...

1 day ago | 0

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Answered
Matlab creates same input values every time? Why?
Every time you load matlab, it does the equivalent of rng('default') which initializes the seed to 0. It is expected that the ...

1 day ago | 1

Answered
generate new coordinates (starting from initial coordinates) that are arranged outwards (by a distance H) and on the same plane
which are arranged outwards (by a distance H) I doubt that you want to arrange the points by distance H, but here it goes. lo...

1 day ago | 1

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...

2 days ago | 2

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 = @(...

2 days ago | 0

Answered
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...

2 days ago | 0

Answered
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 days 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...

3 days 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 ...

3 days ago | 1

Answered
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...

3 days ago | 0

Answered
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...

3 days 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...

3 days ago | 0

Answered
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...

3 days 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...

3 days ago | 0

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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) ...

3 days 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...

4 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...

4 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

5 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...

5 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...

5 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...

5 days ago | 0

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