Community Profile

photo

Walter Roberson


Last seen: Today Active 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. 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.

Programming Languages:
C, MATLAB, Shell, Perl, Fortran
Spoken Languages:
English

Statistics

All
  • Most Accepted 2023
  • Most Accepted 2022
  • Solver
  • First Review
  • Most Accepted 2021
  • Roberson Cup
  • Most Accepted 2019
  • Most Accepted 2018
  • Most Accepted 2017
  • 36 Month Streak
  • Most Accepted 2016
  • Most Accepted 2015

View badges

Content Feed

View by

Answered
How can I displace x and/or y axes from existing positions?
There is no provided way to do this. You will have to turn axes off, and draw the axes yourself.

2 hours ago | 0

Answered
Fastest possible prime number detection without using break or return
The fastest possible way of doing any computation depends upon the fine details of your CPU, and upon the fine details of how me...

2 hours ago | 0

Answered
Processing Multiple Files at once.
[filelist,pathn] = uigetfile('*.*','Please Select a Par File in .dat or .txt', 'multiselect', 'on'); if isnumeric(filelist); er...

2 hours ago | 0

| accepted

Answered
Uploading .mat files that contain nested structs into a datastore
data = matfile(filename, variables{1}); That is the wrong way to use matfile. The proper way to use matfile is matObj ...

7 hours ago | 0

Answered
How can I skip the rest of an if statement?
if n > 1 while true if a == 1 disp('Haha') break % (Here is where I want to skip the res...

7 hours ago | 0

| accepted

Answered
ginput error in matlab 2020a
Error in contains (line 36) tf = ~cellfun(@isempty, strfind(s, pattern)); ... Except that contains is a built-in function and ...

20 hours ago | 0

Answered
How to determine if angles match
You would get that behavior if prec1 or prec2 are non-scalar and it does not happen that all of the values pass the tests.

1 day ago | 0

Answered
How to run a function in app designer?
psi = app.EditField_psi.Value; phi = app.EditField_phi.Value; theta = app.EditField_theta.Value; m = app.EditField_m.Value; ...

1 day ago | 0

Answered
No sound when playing movie in Matlab2020b
%dispMoviesMatlab - ComputerVision Toolbox audiopath = 'C:\Users\maxab\OneDrive\Desktop\Masters\Experiment\Movies\Chosen'; m...

1 day ago | 0

Answered
Where is Shader graphics available in MATLAB
The only access is shading (not very extensive)

1 day ago | 0

Answered
vectorized operations on symbolic functions
syms x1 x2 x3; % symbolic variables y = x1^3/3 + x2^2/2 - x3; % symbolic function y X = rand(500,3); % each row representing a...

1 day ago | 0

Answered
Slice command for terrain
No. Your data cannot be sliced. Perhaps you might want to contour() the data, and get back the contour matrix, and use somethin...

1 day ago | 0

Answered
Extract color map from png apply to grayscale image
Use rgb2ind() on the colored image, and take the second output as being the color map. [~, cmap] = rgb2ind(TheColoredImage); i...

1 day ago | 1

Answered
how to perform a multi variable optimization on matlab
There are several different minimizers possible. Everything except fzero() -- fzero() is restricted to one variable. The trick ...

1 day ago | 0

Answered
Binary GA returns floating point numbers
% Set seed for reproducability rng(42); % Load data and define arrays data = readmatrix('Data/File_S1.xlsx'); X = data(2:e...

1 day ago | 0

Answered
line search minimization problem, error sym is not convertible to double
f = 316.2*(X1^0.5) + 34.3*X2 + (10^8)*(X1^(-0.5))*(1/X2) %symbolic expression %... A=diff(f,X1) B=diff(f,X2) %A1...

2 days ago | 0

| accepted

Answered
Create a list of list and take the mean
cellfun(@mean, aps)

2 days ago | 1

Answered
Unregcognized function or variable 'xotold'
if f2<f1 && f2<f3, xoptold = x2; end You only set xtoptold if that condition is true, but later you use it even if the co...

2 days ago | 0

Answered
Find data from files that are too large to read in
Use buffer-fulls of data for increased efficiency. fread() a block of data of fixed size. Scan backwards through the block look...

3 days ago | 0

Answered
How do I add transparency to a plot in the Live Editor?
Unfortunately, the hack of using a 4-element Color does not work in LiveScript. The work-around is to set the figure Visible pr...

3 days ago | 1

Answered
x axis labels not properly working
You used xticks([-0.8:0.4:0.8]); Instead of xticks([-0.08:0.04:0.08]);

4 days ago | 1

| accepted

Answered
extracting one variable from mux
You do not use a To Workspace block for that purpose; you use a Bus Selector https://www.mathworks.com/help/simulink/slref/busse...

4 days ago | 0

| accepted

Answered
Possibly spurious solutions - Matlab blocked with no answers
Turns out there are some solutions In the below, fullsubs is not actually valid for all entries -- only for entries [5 8 13 16...

5 days ago | 0

Answered
How to find the best combination of angles for minimum turn radius
radius = 72; inner_angle = (0:68).'; outer_angle = (0:68); inner_angle_rad = inner_angle * pi /180; outer_angle_rad = outer_...

5 days ago | 1

| accepted

Answered
How is the work distributed in parfor loop?
You can control how parfor divides up the iterations by using parforOptions() RangePartitionMethod https://www.mathworks.com/hel...

5 days ago | 1

Answered
Vpasolve can not find a solution that I know it exist
There is no solution in the reals. clear clc %% Parameters and Assumptions syms x11 x12 x21 x22 positive % Actions syms a11...

6 days ago | 0

Answered
Attempt to execute SCRIPT ' ' as a function error
This problem is caused by a corruption of the MATLAB installation, one that causes it to lose track of the internal implementati...

6 days ago | 0

Answered
How to get y value?
Xtarget = 900; H = findobj('type', 'line'); xvals = arrayfun(@(h) h.XData, H, 'uniform', 0); yvals = arrayfun(@(h) h.YData, H...

7 days ago | 0

Answered
how would I randomly replace two elements in a row vector
y = char(randperm(27) - 1 + 'A'); for i = 1:iter idx = randperm(numel(y), 2); ynew = y; ynew(idx) = ynew([idx(2)...

8 days ago | 0

Answered
why am i getting the error "Incorrect number or types of inputs or outputs for function step."
The most likely problem is if you do not have Control System Toolbox installed.

8 days ago | 0

Load more