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 T0099119; if you are waiting on a reply from me for an older issue, please send me a reminder.
C, MATLAB, Shell, Perl, Fortran
Spoken Languages:
English
Statistics
RANK
1
of 273,002
REPUTATION
128,682
CONTRIBUTIONS
35 Questions
57,207 Answers
ANSWER ACCEPTANCE
51.43%
VOTES RECEIVED
16,958
RANK
of 18,442
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
Top ten contributors whose answers received the most acceptances in 2022
Awarded to Walter Roberson on 01 Jan 2023
Top ten contributors whose answers received the most acceptances in 2021
Awarded to Walter Roberson on 01 Jan 2022
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
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
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
Content Feed
Is there a way to reduce Timer period to less than 1 ms?
You would need to reimplement timers.
6 hours ago | 0
Find doesn't seem to work with Matrix larger than 127x127
I am certain that find works. I speculate that you are putting the values together in an array with values of datatype int8. Whe...
7 hours ago | 2
| accepted
Accessing the url address of images in Matlab Drive
The files on matlab drive cannot be remotely accessed individually. Even if you publicly share a folder, the share mechanisms do...
7 hours ago | 0
How can I find the Time for specific values of Voltage (with a small tolerance)?
find(abs(data-target)<=tolerance) Or ismembertol()
8 hours ago | 0
I would like to extract x,y,z coordinates of any 3 atoms from a pdb file. How to rectify this error and make it generalized?
% N = range of indices for example N=1:7; Q = [ubq.Model.Atom(N).X; ubq.Model.Atom(N).Y; ubq.Model.Atom(n).Z].'; This...
18 hours ago | 1
Dynamic plot in real time
pick nominal x coordinates for the endpoints of the see-saw. Create a line that has those as the x coordinates and has the "curr...
18 hours ago | 0
Error: File: project_01.m Line: 61 Column: 26
elseif Hexa_number_small = Hexa_row_small * (Hexa_number - 1); elseif must be followed by a condition, not an assignment.
18 hours ago | 0
Error in ode45 (line 115) odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);
delta = 1; That is a numeric scalar. Valid indices for it are numeric 1, logical true, logical false, and the empty vector....
19 hours ago | 0
Why do I get unrecognized function or variable when calling constructor in app designer
TFeature is not a property or method of the class, and it does not exist at the time the properties list is being parsed. It is ...
1 day ago | 0
saving figures to a video with VideoWriter
getframe() with no options is not guaranteed to return the same size each time. In practice the size of an axes can vary by (if ...
1 day ago | 0
How can I specify the dimension of a differentiated function?
diff() is generally successive differences. It is only derivative if the first parameter is sym or symfun, both from the Symboli...
1 day ago | 0
Finding a redundant pattern in a matrix
C1=[ 5 9 3]; C2=[ 9 5 3]; C3=[9 5 9 3]; C4=[5 9 8 3]; C5 = [5 3 9 8]; is_in(C1, C2) is_in(C1, C3) is_in(C1, C4) is_in(C1, ...
2 days ago | 0
Connecting to USB device with serialport vs. serial command
serialport does not have any fopen() or fread() . It automatically opens the port when you create the object, and it uses read()...
2 days ago | 0
Empty matrix, scalar, or vector function in loop
MATLAB uses == for comparisons, not = Also, X = [] Y = 1 if X == []; disp('X yes 1'); end if Y == []; disp('Y yes 1'); end ...
2 days ago | 0
Numeric data becomes zero after conversion from Table
I predict that you have format short in effect, and that what is being displayed is not really 0 but is instead something of t...
2 days ago | 0
| accepted
Why results of the 'solve' are wrong?
p_max=715.685424949238; (and a bunch of other numbers). What does that input mean? Does it mean that p_max is exactly ? Does ...
2 days ago | 1
| accepted
Excel sheet data upload "Invalid 'DataRange'. The column size must match the number of variables".
opts.DataRange = "A2:AT78"; That requests that column "A" to "AT" be read in. However, M1_New_Macro1.xlsx only has data up to c...
2 days ago | 1
Logical operator not evaluating correctly
A|B is an or test and returns a logical value -1 is nonzero which is considered true, and since you or everything together you a...
2 days ago | 0
Hi.How I can plot W_m to n connection
See <https://www.fieggen.com/shoelace/lacingmethods.htm> for some of the possible ways to plot that.
3 days ago | 0
Receiving mouse clicks in App Designer UIAxes - stops working after imshow
https://www.mathworks.com/help/matlab/creating_plots/capturing-mouse-clicks.html MATLAB considers graphics objects to be layer...
3 days ago | 0
| accepted
molecular code in matlab
There are a lot of undefined variables there. There are two possibilities: There might be another script that you have to exec...
3 days ago | 0
Need help coding this
Example. fun = @(x, y) (x + y).^3 - 5*(x.*y) - 1; [X, Y] = meshgrid( linspace(0,2)); z = fun(X, Y); contour(X, Y, z);
3 days ago | 0
I have a data 5x148992 , i have to extract data column wise and check if there is any changes wrt previous column and display when there are chnages?
for i = (data( : , : )) data appears to be a 2D array. When you have something of the form for VARIABLE = EXPRESSION; BODY;...
3 days ago | 0
| accepted
How to add Line/Markers to an Axis Label?
L = "G\prime ( \bullet ) and G\prime\prime ( \color{red}{\bullet}\color{black} ) (Pa)"; ylabel(L, 'interpreter', 'tex') See al...
3 days ago | 0
| accepted
How to calculate the symbolic integration of rational functions?
Wolfram Alpha says https://www.wolframalpha.com/input?i=int%281%2F%28x%5E4+%2B+x%5E3+%2B+x%5E2+%2B+x+%2B+1%29%2C+x%2C+0%2C+1%29&...
3 days ago | 0
Solving large linear systems of equations in parallel / distributed systems
Gb = 60000^2*8/1024^3 The matrix is close to 27 gigabytes. The inverse is the same size, so you will need at least 54 gigabytes...
3 days ago | 0
How to make a new column in my table
elseif requires a expression after it, but you coded an assignment. You just want else not elseif Remember that if Results(...
3 days ago | 0
Need a to plot a graph
hvals = linspace(0,17); numh = length(hvals); Vtotal = zeros(numh, 1); H1 = 11; %in H2 = 5; %in m r1 = 3.5; %in m r2 = ...
3 days ago | 0
Trial download 2021b
only Mathworks Sales can generate trials against older versions.
4 days ago | 1
You can also select a web site from the following list:
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)
Asia Pacific
- Australia (English)
- India (English)
- New Zealand (English)
- 中国
- 日本Japanese (日本語)
- 한국Korean (한국어)