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 T0099089; 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
  • Roberson Cup
  • Most Accepted 2019
  • Solver
  • First Review
  • Most Accepted 2018
  • Most Accepted 2017
  • 36 Month Streak
  • Most Accepted 2016
  • Most Accepted 2015
  • Most Accepted 2011
  • Most Accepted 2012
  • Most Accepted 2013

View badges

Content Feed

View by

Answered
MATLAB codes for Network Reconfiguration using Firefly Algoritm
Yes. This is a MATLAB assignment given to students every couple of years, so someone in the world has MATLAB code for this. I d...

circa 8 ore ago | 0

Answered
Plot over a image
%Plot Sw - r^2/t figure(1) Image2011 = imread('Image2011.jpg'); image([0 1], [0 1], Image2011) colormap jet hold on semilo...

circa 9 ore ago | 0

Answered
function not working properly
The code you post only assigns to valid in situations where it has valid=~1 so it can only ever assign false (0) to valid. There...

circa 9 ore ago | 0

Answered
How to find 0 is present in any bounding box?
It is common to have more than one bounding box in an image. For example if you are tracking faces, then you would expect more t...

circa 9 ore ago | 0

Answered
can you please help me to color the area covered by ABCD in this graph?
coud you please help me to colir the graph? fill([A_x, B_x, D_x, C_x], [A_y, B_y, D_y, C_y]); where (A_x, A_y) are the coordin...

circa 9 ore ago | 0

Answered
How to plot two 3-D figures with different axes in a single plot?
You can use subplot() or tiledlayout() to create two different visually distinct axes that are beside each other horizontally or...

circa 11 ore ago | 0

Answered
I want to find the range of kc that makes s is less than zero
syms s Kc delta real assume(delta >= 0) eqn = 16*s^3 + 280*s^2 + 1400*s + 200*Kc + 2000 == delta sol = solve(eqn, s, 'MaxDegr...

circa 11 ore ago | 0

Answered
How to switch to purchased license after using the free trial license.
MATLAB's license system is designed to let the trial have priority while it lasts, because the trial usually has additional feat...

circa 13 ore ago | 0

Answered
first time matlab user, trying to use fmincon for a simple question
S0 = 1433.32; K = 1430; r = 0.0011; T = 30/365; sigma = .15; x0 = 24.9; x = fmincon(@(y)blackScholesCallPrice(K,T,S0,r,y,sig...

1 giorno ago | 0

Answered
Problem with datetime in German
Observe: datetime('21.Oct.2020', 'InputFormat', 'dd.MMM.yyyy', 'Format', 'dd.MMM.yyyy') So using dots is possible for English....

1 giorno ago | 0

Answered
For loops in non linear equaities - fmincon
function [c,ceq] = nonlconTest(x) n = x(1); That tells us that n is one of the variables being allowed to vary. for i = 1:n ...

1 giorno ago | 0

Answered
how to convert 227x227 image into 227x227x3
https://www.mathworks.com/help/deeplearning/ref/augmentedimagedatastore.html with 'ColorPreprocessing', 'gray2rgb'

1 giorno ago | 0

Answered
Please help me identifying how this person makes his code
funct = @(x) 1-(400/9.81)*(3+x)/((3*x + 0.5*x^2)^3); secant (funct, 0.5,2.5,0.01) function xs = secant( func, x0, xi, es ) ...

1 giorno ago | 1

| accepted

Answered
Storing many digits using readtable
To preserve those digits, you are going to need to read the file as text and store the long numbers as either text or as symboli...

1 giorno ago | 1

| accepted

Answered
How can I plot a few dots in matrix plot?
[X,Y] = meshgrid(6:6:24); scatter(X, Y, 'b*') xlim([0 30]); ylim([0 30])

1 giorno ago | 0

Answered
x=0:pi/100:2*pi; y=sin(x); if x>3 plot(x,y,"b*") else x<=3; plot(x,y,"g*") end I Want PLot X>3 using Defferent Color
x=0:pi/100:2*pi; y=sin(x); mask = x > 3; plot(x(mask), y(mask), "b*") hold on plot(x(~mask), y(~mask), "g*") hold off

1 giorno ago | 0

| accepted

Answered
Plot the trajectory of a motion of x(t) and y(t)
t = linspace(0,10); X = @(t) acos(t/10) + tan(t/10); Y = @(t) (t/10).^2 + (t/10) - 1; plot(X(t), Y(t))

1 giorno ago | 0

Answered
Remove specific field and "push up" its contents without losing the data.
temp = rmfield(Data.c1, 'Data'); fn_temp = fieldnames(Data.c1); fn_c1D = fieldnames(Data.c1.Data); combined_cell = [struct2ce...

1 giorno ago | 0

Answered
Multiple plot on same graph
rng default n = 30; % generate the A matrix D = delsq(numgrid('L',n)); %same as matrix A bGrid = ones(length(D),1); %same a...

1 giorno ago | 0

Answered
why is my plot not showing anything
m0 = 300000; k = 2000; v0 = 1200; y0 = 0; BTLnhom11(m0, k, v0, y0) function BTLnhom11(m0, k, v0, y0) syms t v; ...

1 giorno ago | 0

| accepted

Answered
Solving a Second Order Piecewise Quadratic Equation
syms a b x(t) x__prime = diff(x) x__prime__prime = diff(x__prime) eqn = a/(x__prime__prime*x__prime__prime) == b sol = dsolv...

1 giorno ago | 1

| accepted

Answered
shared licensing of matlab features
Sorry, there is no way of doing that. I see disagreements online as to whether it is possible at all with the underlying licens...

1 giorno ago | 0

Answered
Symbolic vector start name with c0 instead of c1
If you need a vector of variables then c = sym("c" + (0:9))

1 giorno ago | 0

Answered
Solve an equation that has data arrays as constants
You have c^2 and say that c will be an array. Could you confirm that you c^2 meaning c*c meaning algebraic matrix multiplicati...

2 giorni ago | 0

| accepted

Answered
How to see if characters are present in a string array.
You could use multiple contains() tests. But I suggest that instead you do something like ismember(sort(char(InputSeq)), cell...

2 giorni ago | 0

Answered
I had a problem with the following code. The error says that there are "too many input arguments". I know that the problem is from the fsolve equation but I can't to solve it.
theta34(:,i) = fsolve(@position, [1 1],options,th)*180/pi; That th after the options struct will be interpreted according to a ...

3 giorni ago | 0

Answered
How to avoid introducing abs( ) when simplifying expressions using the symbolic toolbox ?
%% Problem 6.4 syms x y x_dot y_dot assume(x,'real'); assume(y, 'real'); assume(x_dot, 'real'); assume(y_dot, 'real'); %...

3 giorni ago | 0

Answered
Can my x-axis have varying scales for certain ranges of values?
Is it possible to scale my x-axis so the intervals are spread further apart from each other for more time-sensitive data and clo...

3 giorni ago | 0

| accepted

Answered
Trying to create neural network but getting a NaN error from dataset
net = trainNetwork(train_X1, string(Y1), layers, options); However: Error using trainNetwork (line 184) The training sequence...

3 giorni ago | 0

| accepted

Answered
Why won't my plot graph a line?
A for loop assigns the loop control variable each column of the expression in turn. After the loop it has the last value it was ...

3 giorni ago | 0

Load more