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Walter Roberson


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48.708 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
Fimplicit not plotting properly
a=2; h=0/2; b=0; g=3/2; f=1/2; c=7; fun1=@(x,y) a.*x.^2+2*h.*x.*y+b*y.^2+2*g.*x+2*f.*y+c; fimplicit(fun1, [-10 10 -10 10]) Lo...

circa 11 ore ago | 1

Answered
How to do a rem while loop?
while true h = input('Enter the desired grid spacing: '); if isnumeric(h) && isscalar(h) && h > 0 && rem(h,1) == 0; br...

circa 11 ore ago | 0

Answered
Laplace transform not found.
The wk^3*exp(x*tau) is getting integrated to include a /tau^4 term -- the general pattern wk^n*exp(...*tau) integrates to someth...

circa 11 ore ago | 0

Answered
matlab error ode45
x0=[0,10,45]; %initial condtion tspan=[0,30];% time span u=10; odefun = @(t,y)reshape(rolling(t,y,u), [], 1); [t,x]=ode45(...

circa 12 ore ago | 0

Answered
vpasolve -> Empty sym: 0-by-1
I was seeing some oddities when I solved, so I tried solving two different ways: R=8.3144; T=298.15; F=96487; eps0= 8.854*10...

circa 18 ore ago | 0

Answered
What does [3, Inf] represents?
In addition to what the others say: that kind of variable would tend to be used as the size parameter for reading data, such as ...

circa 20 ore ago | 1

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Answered
For loop stores all zeros then the actual values of last iteration
Your statement finalsm = zeros(height(x),1); % 'height(x)' bc array changes size each iteration is throwing away all previ...

circa 21 ore ago | 0

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Answered
convert binary string into hex
lookup = containers.Map(cellstr(dec2bin(0:15,4)),cellstr(dec2hex(0:15))); binary_string = '0101010011101010'; output = cel...

circa 21 ore ago | 0

Answered
How to read text file backwards?
You can fopen() the file for reading and fseek() to a particular offset relative to the end of file. You will not be able to fs...

circa 21 ore ago | 0

Answered
ERROR Subscript indices must either be real positive integers or logicals.
for j=1:j_max+1 x=v((j-1:j+N0-2)*dt); j starts at 1. j-1 starts at 0. 0 multiplied by anything is 0. Therefore your first ind...

circa 21 ore ago | 0

Answered
Why do the lines not plot to completion
solution2=ode45(vector2, [0 1], [.39 0]); factor2=((1+b_2)/(F))*(solution2.y(2,:)); % Effective Factor First Order 1 so fact...

circa 23 ore ago | 1

Answered
How Can I Pull A Specific Variable From The Determinant of Matrix?
You have no realistic chance of calculating one variable in terms of the other symbolically. Your function involves the first tw...

1 giorno ago | 0

Answered
How to combine the using of meshgrid and surface?
x = linspace(0,.1); y = linspace(.3, .4); [X, Y] = meshgrid(x, y); Z = X.^2 - 5.*Y.^3 + sin(5*2*pi*X); surf(X, Y, Z, 'edgeco...

1 giorno ago | 0

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Answered
Get rid of unnecessary space in output of full(A)
disp(num2str(full(A))) You can add a format specifier to num2str() to be more specific about widths.

1 giorno ago | 0

Answered
Merge data by date
Convert your data to a timetable() object, and use retime() to consolidate the information.

1 giorno ago | 0

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Answered
Can I pcolor base on wavelength, any colormap can do so?
When you pcolor(X,Y,I) then the I data will be used to decide which color information is used. By default, the numerically lowes...

1 giorno ago | 0

Answered
How to: write .xls into a dynamic folder name ?
folder = [Answer{1},' ',Answer{2},' ',num2str(Answer{3})]; if ~exist(folder, 'dir'); mkdir(folder); end filename = 'patient_...

1 giorno ago | 0

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Answered
How to run continuously
current_state = 0; writeDigitalPin(a,'D2',current_state); while true if readVoltage(a, 'A1') >= 2 if current_s...

1 giorno ago | 0

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Answered
how to solve the error "Not enough input arguments."
You are pressing the green Run button to run the code. Don't Do That. Go down to the command line and command alpham(18.35) al...

2 giorni ago | 0

Answered
[THIS QUESTION HAS BEEN REDACTED]
function [T_mp,rho,cp,k,alpha] = Material_Properties(MN) T_mp_vec = [1406 2192 693 2125]'; rho_vec = [19070 6100 7140 6570]'; ...

2 giorni ago | 0

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Answered
rotating a matrix without interpolation
When you rotate a matrix, then the only pixels that can be calculated without any interpolation are the ones whose coordinates a...

2 giorni ago | 1

Answered
Using size on a data file, etc... Could someone explain what each step here does exactly?
importdata() in some circumstances returns a struct that has a field named data that holds whatever importdata() decided was num...

2 giorni ago | 0

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Answered
Adding accents to the live scripts
That feature was not supported until R2019a.

2 giorni ago | 0

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Answered
Is there a way to remove the Column titles when using format longg?
disp(num2str(YourMatrix))

2 giorni ago | 1

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Answered
How to add a newline after a certain number of characters
while number of remaining characters > n remove and record the first n characters add them and newline to output end ...

2 giorni ago | 0

Answered
download part of ascii file
k=dlmread('11032020_2020-11-25_17-40-55_m1.ascii', ' ',[585 3 1457 4]) asks it to skip 3 columns and that the reading should pr...

2 giorni ago | 0

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Answered
Readtable function on Matlab
Unable to find or open 'Task3.xlsx' Task3.xlsx is not in your current directory, and not in any directory that is on the MATLAB...

2 giorni ago | 0

Answered
`integral` function: "Output of the function must be same size as input" error
integral() will call the given function with a vector of values, and the function must return one value for each element in the ...

2 giorni ago | 0

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Answered
extracting from a matrix
XY_indx = [ 1 1 1 2 1 2 1 2 3 2 2 4 1 1 5 2 1 ...

2 giorni ago | 0

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