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Walter Roberson


43,602 total contributions 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.

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Answered
using improfile in 2D image.
surf(my_image, 'edgecolor','none')

4 hours ago | 0

Answered
how can i set random number generation limit?
You will need to use https://www.mathworks.com/help/stats/prob.normaldistribution.truncate.html to truncate the probability dist...

4 hours ago | 0

Answered
Why does ode45 generate different sized vectors depending on how output is defined?
https://www.mathworks.com/help/matlab/ref/ode45.html#d117e989842 sol = ode45(___) returns a structure that you can use with dev...

4 hours ago | 1

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Answered
I am getting a blank graph when I try to plot a while loop. I am not sure why. My code is below. Thank you MATLAB
You are plotting one point at a time but you have no marker specified. MATLAB never deliberately joins points from different ...

9 hours ago | 1

Answered
How to use scatter function with different marker, markerFaceColor?
You will need to get a job or internship with Mathworks with the goal of extending the scatter object to handle multiple markers...

9 hours ago | 0

Answered
Drawing shape from coordinates
Computer Vision Toolbox insertShape function

10 hours ago | 0

Answered
What units is the number in strel('disk', 22)?
Pixels. Or more correctly, memory locations, as the result is used in multiple contexts and makes no attempt to handle multip...

10 hours ago | 0

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Answered
'.' is not an internal or external command, nor is it a runnable program or batch file
You are trying to run Linux code on ms windows. You will need to change the / in the system() command to \

18 hours ago | 1

Answered
how to open .mat file in matlab?
You are calling importfile1() without passing in a parameter. You cannot run importfile1() just by clicking the green Run butto...

19 hours ago | 1

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Answered
Using strfind to find character index in word
Guess1 = 'e'; HangWord = "each"; index = strfind(HangWord, Guess1);

19 hours ago | 0

Answered
Is vaderSentimentScores available in R2019a
No, it was introduced in R2019b. See https://github.com/cjhutto/vaderSentiment for python library and https://github.com/nunoac...

21 hours ago | 0

Answered
Index Exceeds Number of Array Elements (1)? Line(5)
Line 5 is fid=fopen('Lab1_Problem1.txt'); In order to receive an index out of range in that line, you would have to have a var...

23 hours ago | 0

Answered
How to crop multiple images?
Yes, imageSet requires the Computer Vision Toolbox. imageDir = 'D:\Masters Thesis\ssss'; dinfo = dir(imageDir); dinfo([dinfo....

24 hours ago | 0

Answered
How put a gif on GUIDE
GUIDE does not directly support playing GIFs. What you can do is read the frames of the GIF and store them in an accessible pl...

24 hours ago | 0

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Answered
plotting graph and mark points
d = xlsread('FaceFour_TRAIN.xlsx'); plot(d); hold on idx = find(d>0.04); pointsize = 20; scatter(idx, d(idx), pointsize, 'b...

1 day ago | 0

Answered
how plot only show the value which I selected
Location = menu('Please select a loaction',LocationID); assigns to a variable named Location with an upper-case L fprintf('On ...

1 day ago | 0

Answered
How to compare two matrix?
nnz(A == 1 & B == 3)

1 day ago | 0

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Answered
Optimisation of a filter knowing input and output
First order low pass filters only have a very small number of parameters. If you look at the discrete description at https://en....

1 day ago | 0

Answered
How to avoid the user insert a number with a wrong value
Preventing the user from entering a number that is invalid for the currently selected base is complicated. It requires checking ...

1 day ago | 0

Answered
Help I can't get my code to execute
xd = (-1)*(r)*(thd)*sin(theta)-(numer/(2*sqrt(denom))); where denom = ((c^2)-(r^2)*(theta)); but denom can be negative, and s...

1 day ago | 1

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Answered
I'm using old matrix in given data and adding user data to add onto old matrix. Example Days(16x1), Location(16x5), LocationID(1x5) and when user inputs a day its supposed to add onto Days, Same with new location and LocationID.
Days2(D2) D2 contains day numbers such as 52 and 60, but there are only 16 (before additional data) or 21 (after additional dat...

1 day ago | 0

Answered
Install new info.
LocationID(6) = "some new string" Days(17:21) = vector of 5 day numbers Ice(17:21,6) = vector of 5 numeric values

1 day ago | 0

Answered
I wanna save text as txt file in my desktop or any location I choose
Text='hello'; [file, pathdir] = uiputfile('text. Txt'); if isempty(file); return; end %user cancel fullname = fullfile(pat...

1 day ago | 0

Answered
How to display all decimal numbers for floating numbers?
There are an infinite number of decimal 0's at the end of any floating point number, so it is not possible to make it display al...

1 day ago | 0

Answered
Saving an audio file in .wav format
https://www.mathworks.com/help/matlab/ref/audiowrite.html https://www.mathworks.com/help/dsp/ref/dsp.audiofilewriter-system-ob...

1 day ago | 0

Answered
create matrix with integral
P = 5; for m = 1:P; for n = 1:P; L(n,m) = integral( @(x) fun(x,n).*fun(x,n)), -1, 1); end end function ...

1 day ago | 0

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Answered
Can someone expalin the if statement and the code below it and what does taggedCars doing?
If no blobs are detected then regionprops() would return an empty struct, and [stats.Area] would be empty. In such a case you do...

1 day ago | 1

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Answered
Opening R2018b .m files in R2019b
Quick Access gives you access to paths that were either used "recently" or that you marked as favourite. It does not, however, c...

1 day ago | 1

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Answered
How to send large numbers via UDP?
What is coding them as utf16 ? In any case, use native2unicode() to convert raw bytes that are UTF8 or UTF16 into MATLAB charac...

1 day ago | 0

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