Walter Roberson
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47,234 total contributions since 2011I 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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The contributor whose answers received the most acceptances in 2019
Awarded to Walter Roberson on 01 Jan 2020
The contributor whose answers received the most acceptances in 2018
Awarded to Walter Roberson on 18 Jan 2019
The contributor whose answers received the most acceptances in 2017
Awarded to Walter Roberson on 02 Jan 2018
Solve a problem for the first time
Awarded to Walter Roberson on 10 Jun 2017
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Awarded to Walter Roberson on 09 Oct 2019
Contribute at least one answer each month for 36 consecutive months
Awarded to Walter Roberson on 20 Jul 2017
The contributor whose answers received the most acceptances in 2016
Awarded to Walter Roberson on 20 Jul 2017
The contributor whose answers received the most acceptances in 2015
Awarded to Walter Roberson on 20 Jul 2017
The contributor whose answers received the most acceptances in 2011
Awarded to Walter Roberson on 20 Jul 2017
The contributor whose answers received the most acceptances in 2012
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The contributor whose answers received the most acceptances in 2013
Awarded to Walter Roberson on 20 Jul 2017
Accept 50 answers given by other contributors
Awarded to Walter Roberson on 20 Jul 2017
Reach 25000 reputation points
Awarded to Walter Roberson on 20 Jul 2017
Answer 50 questions that were unanswered for more than 30 days
Awarded to Walter Roberson on 20 Jul 2017
100 of your answers have been accepted
Awarded to Walter Roberson on 20 Jul 2017
How to correct unexpected behavior of `regexprep`?
?: is "group but do not capture" so the () within it do not capture. One approach: regexprep('my.file.ext', {'^([^.]+)$', '^(....
3 hours ago | 0
| accepted
Empty sym: 0-by-1
t6 = th6_;d6 = L;a6 = 0; alpha6 = 0; so t6 uses th6_ A6_= inTransMat(a6,alpha6,d6,t6); and A6_ uses t6, so A6_ uses th6_ T_ ...
5 hours ago | 0
| accepted
How to use dicomwrite after modification
You are constructing file names for all the dcm files in the directory. You iterate over each one, displaying a file name approp...
6 hours ago | 0
fmincon does not converge to the best solution?
fmincon can return a value that is worse than the initial point in some cases, especially if you are using interior-point. It wa...
6 hours ago | 0
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Purchase of toolbox without credit card?
Businesses and educational institutions can (normally) use Purchase Orders. Individuals, businesses, and educational institutio...
6 hours ago | 0
Convert .mat file into .xls file
Your .mat file has two variables that are completely different. Although it is possible in theory to put both variables into the...
7 hours ago | 0
How to use ezplot
https://www.mathworks.com/help/matlab/ref/fimplicit.html is recommended these days. ezplot(@(x,y)x.^2 - 9*y.^2 - 81)
12 hours ago | 0
I tried to import an image in MATLAB that was on my desktop but it returned an error. Please help me out for this
Your current directory is probably not the desktop. The desktop is not on the default matlab path. ls *.jpg
12 hours ago | 0
Rounded random numbers with fixed sum
https://www.mathworks.com/matlabcentral/answers/327656-conditional-random-number-generation#answer_257296 Multiply your desire...
12 hours ago | 0
Reading a hex table with some undefined values
filename = 'hex.txt'; missingindication = {'0xXXXXX'}; data = readtable(filename, 'treatasmissing', missingindication, 'read...
14 hours ago | 0
MATLAB App designer 2019 a
readtable() and set the table itself as the Data property of a uitable() . Use a CellSelectionCallback https://www.mathworks.co...
14 hours ago | 0
How to convert tif stack to dcm series?
fname = 'Sample19.tif'; info = imfinfo(fname); imageStack = []; numberOfImages = length(info); for k = 1:numberOfImages ...
16 hours ago | 0
ttest error - undefined variable - error nanmean nanvar etc.
Error in nanvar (line 29) coder.internal.assert(eml_is_const(dim), ... In R2016b, the release you are using, nanvar has 30...
16 hours ago | 0
Undefined function 'sqrt' for input arguments of type 'char'.
cwt(bigcircle_ant2_data,'amor',1); %produce plot-morlet You are using the calling syntax for newer versions of cwt...
17 hours ago | 0
C = union( A,B ) is too slow. Is there any faster way given that A and B are ordered.
The faster way would involve writing some mex code. There is an undocumented internal binary search routine, but calling it repe...
18 hours ago | 0
What type of error is this?
You accidentally save()'d variables on top of a code file. The code is gone. But you might be able to get something useful fr...
18 hours ago | 0
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Function implementation matlab language
https://www.mathworks.com/matlabcentral/answers/576745-shifting-handling-in-matlab-with-for-loop#answer_476968
19 hours ago | 0
Can I run eigs on a GPU?
eigs really is not supported. https://www.mathworks.com/matlabcentral/answers/572377-accelerate-eigs-with-gpu#answer_472900
19 hours ago | 1
C code generation symbols not found linker error
https://www.mathworks.com/help/images/ref/imadjust.html#bvm6s9t-1 imadjust generates code that depends upon a shared library t...
1 day ago | 0
calculating error while averaging multiple images
Do you want the average of the R, G, and B separately for each image? Are you asking for averages to be taken over time for ea...
1 day ago | 0
Is there a way to get the max memory used when I run my script?
https://www.mathworks.com/matlabcentral/answers/214247-allocated-freed-self-memory-and-peak-memory-in-profiler
1 day ago | 0
how to use datetime(datestr)
Do not try to mix serial data numbers and datetime objects. You can skip most of your problems. t = readtable('data.xlsx'); T...
1 day ago | 0
ode45 does not solve my second order problem
This has exactly the same problem as before. Your left hand side involves z as a function of x, but your right hand side invol...
1 day ago | 1
Line Breaks in command window
disp("SPACING"+newline+newline+"CODE") fprintf("SPACING\n\nCODE\n") disp("SPACING");fprintf('\n'); disp("CODE") disp("S...
1 day ago | 0
| accepted
Error read data from HYCOM
Your url has an extra space at the beginning and the end. I deleted them and tried and had no problem.
1 day ago | 0
How to select a sub square matrix, from a matrix; given the size of the sub square matrix and middle element
use find() with two output arguments to get the row and column of the center. Then use indexing like row-something:row+something...
1 day ago | 0
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How to calculate flotating point
Supposing that the data is stored in F, then char(compose("%.2f %+.2f", round(real(F),2), round(imag(F),2))) This will produce...
1 day ago | 0
How to make a a certain range with different color in colorbar
https://www.mathworks.com/matlabcentral/fileexchange/69470-custom-colormap The above function requires that the positions be d...
1 day ago | 0
'Error - Array indices must be positive integers or logical values
t1 = 0; t2 = 0.04; So t2-t1 is 0.04 - 0 = 0.04 x_2 = v_x1(t2-t1)+x_1 That code attempts to index v_x1 at location t2-t1 whic...
1 day ago | 0
| accepted
How to load library without using mingw64 complier?
See https://www.mathworks.com/matlabcentral/answers/100470-how-do-i-use-loadlibrary-in-a-deployed-program-generated-from-matlab-...
1 day ago | 0
| accepted
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