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Walter Roberson


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47,704 2011 年以降の合計貢献数

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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CEC13 Linux C++
For Visual Studio, %Lf stands for "long double" . https://stackoverflow.com/questions/7822928/scanf-not-taking-in-long-double ...

約9時間 前 | 1

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Simulink doesn't "run" + error 126
https://www.mathworks.com/matlabcentral/answers/285494-why-do-i-see-loadlibrary-failed-with-error-126-when-launching-matlab-r201...

約10時間 前 | 0

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Trouble giving decimal input
0:2 does not express the range starting from 0 and ending at 2. 0:2 expresses a vector of numbers starting from 0 and increme...

約22時間 前 | 1

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Switch block with Strings as Input
You are trying to use a signal that is inherently discontinuous (string) with a continuous time system. Continuous time systems ...

約22時間 前 | 0

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MATLAB 2020b vs earlier versions
The version with about 0.13 is not an especially good fit; it has a sum-of-squared-errors of about 0.06 for the fsolve. You can...

1日 前 | 0

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Is there any method to accelerate many small matrix and vector's "mldivide" (4*4)?
syms tA [4 4] syms tb [4 1]; tx = tA\tb; X = matlabFunction(tx, 'vars', {[tA(:); tb(:)]}); x = X(reshape([a,b], 20, [])); ...

1日 前 | 1

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How to use a symbolic variable to refer to a specific cell on an array
Symbolic variables can never be used to index an array. In particular, you are attempting J(2*m-1,:) . The ':' tells us that J i...

1日 前 | 0

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Extracting Z values from a colormap given a specified X,Y coordinate range
It looks to me as if that is colormap jet. ind = rgb2ind(YourRGBImage, jet(256)); relative_intensity = im2double(ind); concen...

1日 前 | 0

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Is there a faster way to run my code?
[dist_hard, index_hard] = min( pdist2(r, distance, 'cityblock'), [], 2); Note: the distance measure you are using is the L1-nor...

1日 前 | 0

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Simulink real time download on Mac
In R2020a, Simulink Desktop Real-Time is supported on Windows and Mac, but Simulink Real-Time is only supported on Windows.

1日 前 | 0

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Simulink giving unknown error on 2020a
Does the message also talk about bundle start failure? https://www.mathworks.com/matlabcentral/answers/491652-simulink-bundle-3...

1日 前 | 0

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Downgrading my MATLAB version: 2020 to 2019a
You probably have a Student license. Your license entitles you to use any previous version, but it might not entitle you to down...

1日 前 | 2

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Reading character data from .txt file to print statement
S = fileread('YourFile.txt'); titlelines = regexp(S, '^0\s+(.*)$', 'match', 'dotexceptnewline', 'lineanchors'); fprintf('%s\n'...

1日 前 | 0

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Is it possible to determine the angle of rotation for this graph?
If one really was a circshift of the other, then by taking one and repeating it once, you can be sure that it would have a subst...

1日 前 | 0

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Check for hexadecimal number
regexpi(S, '^0X5[A-F][0-9A-F]{2}$') if the result is empty there is no exact match (but it might be a hex number in a diffe...

2日 前 | 0

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Failure in initial objective function evaluation. FMINUNC cannot continue. Need some help
When you have the option SpecifyObjectiveGradient, then your function must be able to return the gradient as well as the objecti...

2日 前 | 2

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How can I install trial version 2016a matlab for 64 bits
You will need to contact Mathworks Sales for custom trials. Mathworks will probably be reluctant to grant a trial for such an o...

2日 前 | 0

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storing unknown matrices size in a single matrix
Use an array structure similar to class_identifier1 student_id1 class_identifier1 student_id2 class_identifier1 student_id3 ...

2日 前 | 0

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Save UIFigure as .jpeg or Add Style to UITable with Figure (not UIFigure) Parent?
As of R2020a it is possible to export a uifigure . https://www.mathworks.com/help/matlab/ref/exportapp.html exportapp does no...

2日 前 | 0

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Computing the outer product (BLAS 2 operation) raised to the power k using the least number of flops
LAPACK and BLAS are designed for computational efficiency, which is not the same thing as reducing the number of FLOPS. The leas...

2日 前 | 0

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sacar la primera, segunda, tercera y cuarta derivada de una función
You just keep going. After Derivada=diff(f,x,1); you can segunda = diff(Derivada, x); tercera = diff(segunda, x);

2日 前 | 0

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How to resize array using a mask
a(logical(cell2mat(mask)),:)

2日 前 | 0

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Student version running on different OS and machine at a time
can I install and run Matlab on the same computer but under different OS? Since this is a dual boot machine, it will be one OS a...

2日 前 | 0

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Skip specific line from a text file
If you use fopen / textscan / fclose, then you can specify 'commentstyle', 'e r r' . That tells it to skip from 'e r r' to the e...

2日 前 | 0

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Files missing from a folder
for K = 1 : 2041 thisfile = sprintf('%d.txt', K); if ~exist(thisfile, 'file'); continue; end %file exists, proces...

2日 前 | 0

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Will Matlab mldivide( \ ) operator use all the available cores when used on multi-node?
It will use up to the current maxNumCompThreads https://www.mathworks.com/help/matlab/ref/maxnumcompthreads.html The number of...

2日 前 | 1

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surrogateopt: Dot indexing is not supported for variables of this type.
Removing the -nojvm solves the problem (for reasons currently unknown.)

2日 前 | 2

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Numerical integration of symbolic equation
This is impossible to do as a numeric integration.

3日 前 | 0

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specifying the horizontal linetype '_' produces an error.
https://www.mathworks.com/help/matlab/ref/linespec.html horizontal line style is '-' not '_'

3日 前 | 0

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Solve Function Doesn't Give The Solutions
Warning: Solutions are parameterized by the symbols: x. To include parameters and conditions in the solution, specify the There...

3日 前 | 0

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