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Walter Roberson


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49.248 total contributions 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.

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Answered
How do I find the indices of NaN values in a cell array?
The below accounts for the possibility of multiple nan blocks. It does not, however, account for the possibility that the first...

11 minutos ago | 0

Answered
monts in year sequence, string, matrix
Convert to a timeseries() object and use retime() Or: Data = rand(365,1); Data_timestamp = datetime(2021, 1, 1:365).'; %use ...

alrededor de 1 hora ago | 1

| accepted

Answered
Index exceeds matrix dimensions. in for loop !
for i=1:Np x(: , i+1) = f(x(: , i) , U(:,i)); That needs to access up to the Np'th column of U Cost ([1;1;1;1;1;1] , ...

alrededor de 2 horas ago | 0

Answered
Keeping track of the Index while using "cell2mat" function
key = cell2mat((arrayfun(@(IDX) [repmat(IDX, size(a{IDX},1), 1), (1:size(a{IDX},1).']) , 1:numel(a), 'uniform', 0)); Now index ...

alrededor de 2 horas ago | 0

| accepted

Answered
Can't plot a graph no matter what I do
if check1 == 1 && check2 ==2 && check3 ==1 elseif check1 == 1 && check2 ==2 && check3 ==1 Thoseare the same conditions...

alrededor de 6 horas ago | 0

Answered
How can I code pseudo random binary sequence input current signal made by idinput?
When your functions use random numbers, such as your call to randn(), then they are never ODE (Ordinary Differential Equations)....

alrededor de 16 horas ago | 0

Answered
how to implement Bessel's function in MATLAB
https://www.mathworks.com/help/matlab/ref/besselj.html for the numeric version https://www.mathworks.com/help/symbolic/besselj....

alrededor de 16 horas ago | 0

Answered
Not understanding the function input arguments
X_full (first paramter): A column vector of floating point data Y_full (second parameter): A column vector of floating point da...

alrededor de 16 horas ago | 0

Answered
Define a collection of variables
mons = {'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'...

alrededor de 20 horas ago | 0

Answered
Issue with vectors being the same length
x1 = linspace(xa,xb,nn)'; x2 = linspace(xb,xc,nn)'; xx=[x1;x2]; so xx ...

alrededor de 23 horas ago | 1

| accepted

Answered
Use arrayfun and cellfun to avoid for-loops
for i= 1:length(Categories)-1 for j= i+1:length(Categories) % separated_data is a 3D array of data, I ...

alrededor de 23 horas ago | 0

| accepted

Answered
fmincon for bounded optimization problem
Generally speaking, functions without bounds can take indefinite time to minimize if the function has an asymptope | ...

alrededor de 23 horas ago | 0

Answered
How to find a shortest path from a node to a sub-network?
https://www.mathworks.com/help/matlab/ref/graph.shortestpathtree.html TR = shortestpathtree(G,s,t) computes the tree of short...

1 día ago | 0

| accepted

Answered
What is the Fourier Function of Matlab doing?
https://math.stackexchange.com/questions/1707452/what-is-the-fourier-transform-of-fx-x2 syms x w FT(w) = fourier(x^2, x, w) ...

1 día ago | 0

Answered
Matrix and solve command, Why this is not working please help me.
You asked to solve two equations for a single variable. Except in some cases involving inequalities, you should ask to solve wit...

1 día ago | 1

| accepted

Answered
complex value of syms function for optimization
syms a b c d ; b=c+j*d; Okay, b is a symbolic number that might or might not be complex. "might not be" because d could be 0, ...

1 día ago | 0

Answered
Converting a whole number to base 2 (Binary Operation)
Consider 19 as an example. 19 is odd, which is to say that the remainder when divided by 2 is 1. Write down the 1, subtract it ...

1 día ago | 0

Answered
Combination of numbers, lock
compose("%03d",0:999)

2 días ago | 0

Answered
importing the excel data into matlab in symbolic math tool
Your X is a vector with four elements. When you use it in the equations you are creating a system of four simultaneous equations...

2 días ago | 0

Answered
Creating Random Sparse Matrices Using For Loop
N = 100; S = 100; RM = cell(N,1); B = zeros(1,N); for K = 1 : N RM{K} = sprand(S, S, 0.01); B(K) = bandwidth(RM{K})...

2 días ago | 0

Answered
Task,solving in the fastest way
how to get a solution the fastest Commercial quantum computers are available from DWave and IBM. HP expects to release its vers...

2 días ago | 1

Answered
Simplifying solution of a differential equation
m = rand(); k = rand(); syms y(t) Dy = diff(y,t); Dy2 = diff(y,t,2); ode = m*Dy2 + k*y == 0; cond = [y(0) == 1,Dy(0) ==...

2 días ago | 0

| accepted

Answered
Image texture on face vertice 3D Model
If you have empty faces, then nothing can be drawn there. Perhaps you should use boundary() https://www.mathworks.com/help/matl...

2 días ago | 0

Answered
Can anyone suggest how to change the display allignment in command prompt for seeing list of equations
syms x eq(1,1) = expand((x-1)^2); eq(2,1) = expand((x-1)^10); eq char(eq) arrayfun(@disp, eq)

2 días ago | 0

Answered
there is error in x1(t)
syms t t0 u(t)=piecewise(t<t0, 0, t>=t0, 1); x1(t)=2*u(t-1)-2*u(t-3); T = 0:1/50:10; X1 = double(subs(x1(T),t0,0)); plot(...

2 días ago | 0

| accepted

Answered
Changing value when first time a value appears
A=[1; 1; 1; 1; 2; 2; 4; 4; 4; 4] B=[4; 2; 7; 9; 5; 0; 2; 6; 1; 0] [~, ia] = unique(A, 'stable') B(ia) = nan

2 días ago | 1

| accepted

Answered
Function 'daysact' not supported for code generation.
Correct. That function cannot be compiled. The work-around is to use datetime and subtract. dt1 = datetime('7-sep-2002','Loca...

2 días ago | 0

Answered
How could I use display function for this?
If you mean the derivative as in then MATLAB does not have any direct way to display that in any kind of nice format. All it h...

3 días ago | 0

Answered
Newton Raphson. How to solve it?
If you are using the symbolic toolbox, then MATLAB has jacobian() Otherwise, you need to estimate the jacobian, which you can d...

3 días ago | 0

| accepted

Answered
Can I delete the file mw_4a_config.bin from the licenses folder?
The implication of https://www.mathworks.com/matlabcentral/answers/367213-why-do-i-get-the-error-something-unexpected-occurred-a...

3 días ago | 0

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