# 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**

I want to make a matrix for each change of value

tfile = tempdir + "assign_S.m"; fid = fopen(tfile, 'w'); for K = 1 : 345 fprintf(fid, 'S%d = S; S%d(1,%d) = 2;\n', K, K, K...

2 hours ago | 0

| accepted

No 'FunctionTolerance' or 'TolFun' in gaoptimset

I just ran that code in the version you indicate, R2014b. I get a different result than you do: options = gaoptimset options...

2 hours ago | 1

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audioread() sampled data type conversion

audioread() with 'native' will only return an integer data type if the data is stored as integer internally. That is not always ...

3 hours ago | 0

rectangle command not working in a function with multiple variables in the coordinate argument

driverx = 2; drivery = 1; You do not declare those as global in the function you make the assignments in. global driverx driv...

3 hours ago | 0

for loop in if statement, changing value of matrix element depending on its nearby elements

Subtract the middle number from the entire matrix. If all of the results are less than -20 then the middle was at least 20 more ...

4 hours ago | 0

How to implement Array factor in MATLAB?

phi=[90:90:360 zeros(1,12); 22.5:22.5:360] is a 2 x 16 array. AF(m,i)=exp((1j)*(((k)*(r(m))*(sin(deg2rad(theta)))*(cos...

4 hours ago | 0

Hey guy, can you help me. I build i prime number finder, but it always start with 3 as the first number but i need 2 to start, because otherweise 73 isnt the 21 prime number

for z=2:1:n for t=2:1:z-1 if mod(z,t)~=0 You start checking numbers from 2. Your se...

4 hours ago | 0

Running copies of a figure simultaneously?

Edit the .m file produced by GUIDE. Very early on, about line 25, you will see % Begin initialization code - DO NOT EDIT g...

7 hours ago | 0

for loop with multiple indices

That is not possible for the general case where N is not the same as (M-1) -- that is, if the two variables to be incremented do...

8 hours ago | 1

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Using MATLAB command can anyone solve this questio

syms A [2 2] syms b [2 1] syms x [2 1] eqn = A^2 * x == b solution = solve(eqn, x)

8 hours ago | 0

trying to stop my loop with below an error

u(i,j)=(1/4)*(u(i-1,j)+u(i,j-1)+u(i+1,j)+u(i,j+1)) You always write additional entries into u, never overwriting existing e...

11 hours ago | 0

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Add zero decimal digits in order to have all the elements of a matrix with same number of decimal digits

https://www.mathworks.com/matlabcentral/answers/1599329-insert-blank-cells-in-a-matrix#comment_1863670 I already showed you ho...

16 hours ago | 0

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...

1 day 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...

1 day 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...

1 day 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...

1 day ago | 0

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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...

1 day 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...

1 day 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...

1 day 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...

1 day 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...

2 days 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....

2 days 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 ...

2 days ago | 0

how to convert 227x227 image into 227x227x3

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

2 days 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 ) ...

2 days ago | 1

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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...

2 days ago | 1

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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])

2 days 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

2 days ago | 0

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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))

2 days 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...

2 days ago | 0