# 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 T0099089; if you are waiting on a reply from me for an older issue, please send me a reminder.

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**Content Feed**

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

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

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

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

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

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

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

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

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

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

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

how to convert 227x227 image into 227x227x3

https://www.mathworks.com/help/deeplearning/ref/augmentedimagedatastore.html with 'ColorPreprocessing', 'gray2rgb'

1 giorno ago | 0

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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