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# Walter Roberson

##### Last seen: Today
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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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

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

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

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

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

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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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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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

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

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

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

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

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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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

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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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

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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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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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

[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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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

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

2 giorni ago | 0

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

2 giorni ago | 1

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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

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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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

`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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