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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 T0099000; if you are waiting on a reply from me for an older issue, please send me a reminder.

Programming Languages:
C++, C, MATLAB, Shell, Perl, Fortran
Spoken Languages:
English

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Answered
How to integrate such complicated expression in matlab?
syms A B gamma_s k m sigma_e sigma_r y real inner = (gamma(1+m) + igamma( 1+m, (gamma_s*(1+y)-1) / (A*sigma_r^2) )) .* y.^k ....

1 hour ago | 0

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Answered
Can you tell me how you solved the ode45 for equations of motion?
ode45() cannot deal with those kinds of systems. Runge-Kutta solvers assume that the given equations have continuous first and s...

2 hours ago | 0

Answered
can any body solve this......
No. You have unknown functions and . You have four equations. In order to solve the differential equations, you need at leas...

2 hours ago | 0

Answered
Read matrices that are separated by underscores in a text file.
In the below, the assignment to S1 inside isunix() is just to load in some data since I do not have your file. In your actual co...

3 hours ago | 0

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Answered
Hi. Is 12345 the only seed to generate weibull random numbers with the function wblrnd?
Use any seed you want that is an integer between 1 and 4294967295 (inclusive) rng seed 0 is not permitted.

3 hours ago | 0

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Answered
how do i keep symbolic solver from creating a 1x3 sym instead of 1x1 sym that I want
Well, that is not right. You should be getting two solutions each. You have a quadratic equation, so you should expect two solut...

3 hours ago | 0

Answered
Figuring out how to set custom RGB colors in fill function in R202b
cmap = [0 0 .3333; 0 0 .6667; 0 0 1]; tt = 1:.5:10; lb1 = tt; ub1 = 2.*tt; x2 = [tt,fliplr(tt)]; inBetween = [lb1,fliplr(...

4 hours ago | 1

Answered
Why indexing returns values from first two columns and not from the whole matrix?
your ismembertol is going to return something with the same number of elements as lat_txt (first operand) but then you try to us...

6 hours ago | 0

Answered
Error with Matlab Solve Function
You have Maple installed on your computer and you asked it to install the connection software between MATLAB and Maple. You are ...

14 hours ago | 0

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Answered
Surface plot error for Z must be a matrix, not a scalar or vector
careful, x is (eventually) going to be 3d, and the way you use size is wrong for 3d. I have seen cases where z was returned a...

21 hours ago | 0

Answered
(HOW) I need the code run again if the ( else condition return ) till give me value
do_again = true; while do_again do_again = false; for i= 1:7 for j=1:7 if (i~=j) if % coditi...

1 day ago | 0

Answered
Is there a way to overlay a graph onto a video, plotting each successive point with each frame?
I recommend videofig() from the File Exchange. https://www.mathworks.com/matlabcentral/fileexchange/29544-figure-to-play-and-ana...

1 day ago | 0

Answered
Compute operation with different index (part II)
It would be easier if you would switch over to table or timetable instead of using timeseries . filename = 'https://www.mathwor...

1 day ago | 0

Answered
warning message using surf
We cannot tell what length(u) or length(v) or size(Xq) or size(Yq) is. You could get an error if size(Xq) is not the same as si...

1 day ago | 0

Answered
How to change patient name?
P = zeros(256, 256, 263); for K = 263 : -1 : 1 petname = sprintf('%03d.dcm', K); info(K) = dicominfo(petname); So in...

1 day ago | 0

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Answered
Solve taking too long, how to optimize code?
k = 180; length = .05; b = .01; T0 = 180; Tinf = 25; h = 25; Tsurr = 290; epsilon = 0.9; theta = atan((b/2)/length); ...

1 day ago | 0

Answered
Can you give me the code for Stabilogram Diffusion Analysis (SDA)?
<https://isbweb.org/software/movanal/stamp/>

1 day ago | 0

Answered
Unable to read UDP data with parfeval
When you use parpool (at least if you do not use the "threads" option, not sure about threads), then the workers are in a separa...

1 day ago | 1

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Answered
GUI new callback name
I can tell that you are using a GUI created with GUIDE. Edit ConvertMatLab_gui.m Near line 31 you will find lines % Begin in...

1 day ago | 1

Answered
It's a question about menu function.
Each time menu() is called, it creates a new figure() .

1 day ago | 0

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Answered
Import txt file into MATLAB for Comparison of 2 files to measure bit errors
B1 = fileread('1.txt') - '0'; B2 = fileread('2.txt') - '0'; L1 = length(B1); L2 = length(B2); if L1 ~= L2 fprintf('fir...

1 day ago | 0

Answered
how to decrease the x-axis from left to right
set(gca, 'XDir', 'reverse')

1 day ago | 0

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Answered
Convert a Cell array with char and white spaces to Cell array with double without white spaces
filename = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/750699/sample%20data.xlsx'; opt = detectImportOption...

1 day ago | 0

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Answered
What " lo=3 " means in system option???
https://www.gams.com/34/docs/UG_GamsCall.html lo=3 means all of the output of the executable is to be written to "standard out...

1 day ago | 0

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Answered
how to delete repeated rows in a table?
format long g M = [518460 3.322; 518460 -12.984; 518520 3.798; 518520 -10.28; 518580 7.763; 518580 16.851; 518640 5.959; 522225...

1 day ago | 1

Answered
Matrix Dimensions must Agree
Your D_pca has 4 rows and an unknown number of columns. Your eigvects has 2 rows and an unknown number of columns. D_pca(:,1)*...

1 day ago | 1

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Answered
multiply by two matrix
syms x n = [1.521, 2.66]; k0 = 1; h = [1.5e-6, 1e-6]; k = @(j) sqrt(n(j).^2*k0.^2-x.^2); M = @(j) [ cos(k(j) ....

1 day ago | 0

Answered
Trying to compress a signal.
compressed_x = x(1:2:end);

2 days ago | 0

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Answered
Plotting function, which includes a sum
When you provide a start value, you also have to provide a count -- even if you just provide inf as the count.

2 days ago | 0

Answered
absolute value in equality constraints
N = 5; var10 = optimvar('var10', N); var9 = optimvar('var9', N); var7 = optimvar('var7', N); prob = optimproblem; ABS = @...

2 days ago | 0

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