Walter Roberson
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.
C++, C, MATLAB, Shell, Perl, Fortran
Spoken Languages:
English
Statistics
RANK
1
of 243,787
REPUTATION
116,412
CONTRIBUTIONS
34 Questions
52,663 Answers
ANSWER ACCEPTANCE
52.94%
VOTES RECEIVED
14,947
RANK
of 17,054
REPUTATION
N/A
AVERAGE RATING
0.00
CONTRIBUTIONS
0 Files
DOWNLOADS
0
ALL TIME DOWNLOADS
0
CONTRIBUTIONS
0 Posts
CONTRIBUTIONS
0 Public Channels
AVERAGE RATING
CONTRIBUTIONS
0 Highlights
AVERAGE NO. OF LIKES
Reach 100000 reputation points. Honors the first contributor to reach this milestone, Walter Roberson
Awarded to Walter Roberson on 14 Aug 2020
The contributor whose answers received the most acceptances in 2019
Awarded to Walter Roberson on 01 Jan 2020
Solve a problem for the first time
Awarded to Walter Roberson on 10 Jun 2017
Publish your first review
Awarded to Walter Roberson on 09 Oct 2019
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
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
Awarded to Walter Roberson on 20 Jul 2017
The contributor whose answers received the most acceptances in 2013
Awarded to Walter Roberson on 20 Jul 2017
Content Feed
Removing commas between columns in text data
test = {'Sometimes, ,, I, use, commas, .' 'I, like, writing, ,, I, like, reading'}; test = regexprep(test, {'(?<=[^,]),\...
44 minutes ago | 0
griddata command returns all NaN values
for a = 1:100 X1(a) = (5/100).*a; X1 is linear in a. c = a/50; a is a double precision integer, 1 to 100. c is the inte...
8 hours ago | 0
Sending four byte commands To serial port
cmd = [0x81 0x12 0x00 0x00]; write(YourPortObject, cmd, 'uint8'); response = read(YourSerialPortObject, 4, 'uint8'); if ise...
9 hours ago | 0
| accepted
Integer eigenvalues in Matlab
Take the symbolic determinant of (matrix minus lambda) . Ask to factor() that. Look for the entries of the form (lambda +/- inte...
11 hours ago | 0
I can't understand the following MATLAB code documentation
The implication is that the second part is stored in its own file.
11 hours ago | 1
Count from 1 to 0 with increment of 0.01
You need to use a negative increment to count down from a higher value to a lower value.
22 hours ago | 0
Equivalent python for a matlab line?
X = Y[z[i, 0:11],0] would be my guess. However, this relies upon the values in z having been changed to index 0 based instead ...
22 hours ago | 0
What is the difference between [v' 1] and [v', 1]?
v = ((1:3) -(2:4)*1i).' [v' 1] [v', 1] You can see that even for complex numbers, [v' 1] and [v', 1] produce the same results...
22 hours ago | 0
How can I sum each 3 columns array?
reshape(x, size(x,1), 3, []) now you can sum along the second dimension, and then reshape to remove the now-singular second di...
23 hours ago | 1
MATLAB Compiler for a .mlapp that have a .m file
https://www.mathworks.com/help/compiler/unsupported-functions.html Functions Not Supported for Compilation by MATLAB ...
24 hours ago | 0
Increase number of parallel pools coworker by adding hardware?
Check your Parallel Preferences https://www.mathworks.com/help/parallel-computing/run-code-on-parallel-pools.html And check t...
24 hours ago | 0
Datetime doesn't work in uitable
Your reference to handles.file_table tells us that you are using GUIDE and "traditional figures". And in traditional figures, ui...
1 day ago | 0
| accepted
How can I split time series in a half?
ts1 = timeseries(rand(1,4096)); %official approach. uses indices ss2a = getsampleusingtime(ts1, 1, 2048); ss2b = getsampl...
1 day ago | 0
| accepted
Symbolic integration of Marcumq.
Using the online tool here, execution can get through the calculation of "outer", but the integrals might take a while. Could y...
2 days ago | 0
give me invalid use of operator at U, why?
U = 0.75*exp(-((xmid-0.5)/0.1). 2)'; my guess is that you wanted U = 0.75*exp(-((xmid-0.5)/0.1).^2)';
2 days ago | 0
What should go in a next-generation MATLAB X?
The ability to assign a subset of fields to a struct (array) would be useful. It is common to want to be change a few settings, ...
3 days ago | 0
Finding global maxima and minima
Use calculas. The minima and maxima of a function can only occur at: Critical points of the function; or The boundaries that ...
3 days ago | 0
stacking or appending tables with NaN and 'ABC' -- cell vs non-cell
If I understand correctly, you are looping reading multiple files, and want to put the results all into one large table. And tha...
3 days ago | 0
| accepted
一つの列の中の任意の範囲内に正と負の値が両方がある場合に、その範囲内の値を０に置換するにはどうしたらよいですか。
range = 3; A = [1,2,-3,4,5,6,7,8,9] A(A < range) = 0
3 days ago | 0
ODE15s Errors defining variable and ODE functions
Your equations involve components which subtract out T0 and P0. When you initialize the boundaries to T0 and P0 that results in ...
3 days ago | 0
Polynomial has more than one symbolic variable error
syms m1 m2 J1 s b k1 k2 k3 r1 xi T real t=0:0.5:100; A=[-s^2*m1-s*b-k2, k2, 0; -k2, s^2*m2+k3+k2, -k3; -s^2*J1/r1-s*b/r1, 0, 0...
3 days ago | 0
Asking a user in the command window to enter YYYY-MM-DD HH-MM-SS-MS
T = input('Enter time in the form YYYY-MM-DD HH-MM-SS-MS: ', 's') This will give back a character vector that has not been vali...
3 days ago | 0
Matlab system and ! commands point to wrong python version?
This is expected. Using ! or system() find the python that is first in your system path, which might not be the same one you hav...
3 days ago | 1
| accepted
Index timetable variables and remove rows based on criteria.
TT(any(TT{:,2:2001} >= 8,2), :) = [];
3 days ago | 0
| accepted
Random matrices with constraint
t = rand(n, n); nt = t./sum(t,1); output = nt.*rand(1,n); nt is normalized so that the sum of each column is 1. The s...
4 days ago | 1
Extract data from timetable for specific months
[~, mon, ~] = ymd(TT.t1); mask = ismember(mon, [1 2 12]); TTsubset = TT(mask,:); Or if you were looking for specific months...
4 days ago | 0
| accepted
My code will not run after adding in the code after function dydt=myFunc(t,y)
function dydt=myFunc(t,y) t will be a double precision number representing the current "time". t will seldom be an integer duri...
4 days ago | 0
Help For Running MVC2
I suspect you might have started running the program by double-clicking on the .fig file. You need to execute the .m file instea...
4 days ago | 1
readtable : set up the multiple lines of variables
filename = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/760511/A001.txt'; opt = detectImportOptions(filename...
4 days ago | 1
| accepted
