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Walter Roberson


40,307 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
Hi. Is it possible to code an image crop then proceeds to block matching and finally run a newton rhapson power flow method?
if size(original_image,3) == 1 original_image = original_image(:,:,[1 1 1]); %convert to RGB end img_diff = sum((double(...

1 hour ago | 0

Answered
How can I convert my .txt files to .xls using xlswrite
I am a bit confused about your header. You seem to show a line of header, but the format you used for textscan was as if you no ...

6 hours ago | 0

Answered
Running, giving input and handling output of a FORTRAN program in MATLAB.
On the fortran side, extract the real and complex portions and write them separately, like write(22,*) column1, real(column2)...

6 hours ago | 0

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Answered
I'm writing a code for projectile motion and i got a code but I'm not sure how to convert For loop into a while loop
for variable = start : increment : last code section end with positive increment can be converted into hidden_variable =...

7 hours ago | 0

Answered
how to increase license of matlab r2017a?
You should contact Mathworks sales . You would generally be permitted to pay software maintenance retroactively for aa few year...

9 hours ago | 0

Answered
How to extract x,y,z coordinates from 3D Dicom Images?
https://www.mathworks.com/matlabcentral/answers/399483-reference-to-non-existent-field-pixelspacing and be sure to follow the...

11 hours ago | 0

Answered
can i make a symbolic function without a specific formula?
syms XX tt = num2cell( [XX == x(:),y(:)].' ); ff(XX) = piecewise(tt{:}); Now if I got everything right then ff should be a sy...

23 hours ago | 0

Answered
how do i select a line but not all ?
RS(1,3:end)

23 hours ago | 0

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Answered
I am creating a function that alphabetizes an array of strings. It is close to finished but some of the strings are out of order. Any help with fixing it?
you are comparing each letter to each other letter and you are overwriting all of the variable less each time you compare .

1 day ago | 0

Answered
Need help with Operands operators must be convertible to logical scalar values
your x2 is not a scalar. You need to figure out whether it is an error in the code that permits the value to be empty or aa vect...

1 day ago | 0

Answered
When I try to open MATLAB, I get the following error: your username doesn't match the username in the license file
https://www.mathworks.com/matlabcentral/answers/99457-how-do-i-activate-matlab

1 day ago | 0

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Answered
Index in position 1 is invalid. Array indices must be positive integers or logical values.
somehow you have aa variable in your workspace that is named Px so matlab thinks you are indexing instead of calling a function ...

1 day ago | 0

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Answered
How do i accept only numbers as input to forward to a switch case ?
For limiting choices use menu() or aa drop down menu or the like. Do not use ismember with floating point numbers: use ismember...

1 day ago | 1

Answered
i have an error saying Undefined function 'imageSet' for input arguments of type 'char'.which function should i use instead
requires r2014b or later and the Computer Vision Toolbox

2 days ago | 0

Answered
Convert long Hex String to array of uint16
t = temp - '0'; mask = t>9; t(mask)=t(mask)-39; out = t(1:2:end)*16+t(2:2:end);

2 days ago | 0

Answered
sum of variable-size subvectors of array without loops
cumsum . Then the problem reduces to a linear difference of positions .

2 days ago | 1

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Answered
Why the editing privilege is gone?
this bug has been identified and will be fixed on Wednesday .

2 days ago | 0

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Answered
Converting hexadecimal to decimal in base 10 using a loop (not function hex2dec)
if y > 47 & y < 58 should be indexing y(i)

2 days ago | 1

Answered
How to solve an linear set of equations with arbitrary number of symbolic elements
U_t = U.'; Remember that the ' operator is conjugate transpose.

2 days ago | 0

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Answered
I want to resize the images of whole database and then replace it with the same images. The problem is how to create or access the database for images.
Database = imageSet('Palm','recursive'); for i=1:size(training,2) Filenames = Database(i).Locations; for j = 1:t...

3 days ago | 0

Answered
Which one is better for live video encryption matlab or python....???
Simulink with HDL Coder and https://www.mathworks.com/help/visionhdl/index.html Vision HDL Toolbox, to generate VHDL or FPGA so ...

3 days ago | 0

Answered
How do I reverse the direction that data scrolls?
Currently, you are incrementing time for each received sample, and using time as the x coordinate when you addpoint() Change ...

3 days ago | 0

Answered
What is the error of my code and how to solve it ??
Either you tried to paste that into the command line, or else you put it all in one file and you are using R2016a or earlier. It...

3 days ago | 1

Answered
Increase matlab online drive space for student license?
https://www.mathworks.com/products/matlab-drive.html Put your license under software maintenance.

3 days ago | 0

Answered
Good morning please how can I solve the license Manage error-114
My License Manager Cheat Sheet <https://www.mathworks.com/matlabcentral/answers/404028-license-error-cheat-sheet> says that you ...

3 days ago | 0

Answered
How could I fix my last function(less=isLessWord(wordA,wordB)) in my code to get the result I want without using any built-in functions?
Not possible. All MATLAB computation requires a function call. About all you can do without function calls is assign scalar cons...

3 days ago | 0

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Answered
Fmincon error: Field assignment to a non-structure array object.
The nonlcon parameter position is required before the options. Also you are passing extra parameters which can confuse fminco...

3 days ago | 0

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Answered
Home edition - Can I get the coder ?
It has not changed. None of the compiler or code generation products are available for the Home license at this point.

3 days ago | 0

Answered
Overdetermined system of equations - 8 degree polynomial
"Given the fact that equations are linear, is this an inherent problem of matlab?!" It is inherent in using finite precision ...

3 days ago | 0

Answered
Overcome for loops for fast processing
skin_rgb = zeros(256.^3,1); for i = [2000 : 2003, 2008, 2010:2011, 2013:2015, 2017:2018, 2021, 2024, 2027:2041, 2043, 2045:...

3 days ago | 1

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