Community Profile # David Hill

Last seen: Today Active since 2017

Electrical Engineering with minors in Computer Science, Mathematics, and Creative Writing.

Working as Undergraduate Research Assistant in the field of Computational Photonics

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summations and selections of the columns of a matrix
newMatrix=[yourMatrix(1,:);flipud(cumsum(flipud(yourMatrix(2:end,:))))];

9 minuten ago | 0

How can i solve this problem
Show me what you have tried for the C(k) equation above. function C= FourierSeries(x,MaxK) N=length(x); n=0:N-1; for k=1:2*M...

ongeveer een uur ago | 0

I am unsure of how I am getting this error
r=linspace(0.001,1,1000); s=0.75*((r.^3)./(exp(1).^(.75*r)));%error is here (multiplying by scalar does not need .*, but you ne...

ongeveer 16 uur ago | 0

make a matrix of values from questions from another matrix

ongeveer 16 uur ago | 0

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For loop and matrices w/ different elements?
B(i)=[m2.*A2x(i); m2.*A2y(i); I2*a2; m3*A3x(i); m3*A3y(i); I3*a3(i); m4*A4x(i)-F4x(i); 0];%ne...

ongeveer 18 uur ago | 0

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How to code with for loop loops without using ndgrid?
count=0; for c=5:6 for b=3:4 for a=1:2 count=count+1; d(count,:)=[a,b,c]; end ...

ongeveer 18 uur ago | 0

How to divide a vector into small groups
x=randi(100,30,1); X=reshape(x,2,[]); [~,idxGroup]=find(X==x(15));

ongeveer 19 uur ago | 0

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Extracting the sub-matrix
A = [1 2 3; 4 5 6; 7 8 9]; B=A(1:2,2:3); E=blkdiag(zeros(2),A);

ongeveer 19 uur ago | 1

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plotting a 2-colum 2d array
plot(a(:,1),a(:,2));

11 dagen ago | 1

Not enough Input arguments in integral function
s=0:100; for t=1:numel(s) fun_W=@(k)real(c_k(k))./k.*sin(k*s(t)); W(t)=2/pi*integral(fun_W,0,Inf); end fu...

13 dagen ago | 1

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How can I sum each 3 columns array?
m=movsum(x,3); y=m(:,1:3:end);

14 dagen ago | 1

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Cropping images around the center of an image with a particular size

14 dagen ago | 0

Too many for loops, how to approach rearranging arrays problem differently?
a=1:10; b=10:19; sa=0;sb=0; for k=2:numel(a) sa=sa+sum(nchoosek(a,k),'all'); sb=sb+sum(nchoosek(b,k),'all'); end

14 dagen ago | 0

How can I fix random numbers in a for loop?
t=1:.1:10; for k=1:10 s1=randi(5)*sin(1*t)+randi(5)*sin(2*t); s2=randi(5)*sin(1*t)+randi(5)*sin(2*t); Diff(k)=(s1-s2); e...

14 dagen ago | 1

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For loop broken ?
rho = (20-h(n)/1000)/(20+h(n)/1000)*1.225;%h(n) is always going to be zero rho = (20-h(n-1)/1000)/(20+h(n-1)/1000)*1.225;%did y...

17 dagen ago | 0

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How to save for loop output to column vector
No loops needed, although you never defined hbar. fvf= 2888.7; ccm = 3*10^8*100; h = 6.63*10^-34; v1 = ccm*fvf; invAvkg = 1...

17 dagen ago | 0

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Function Approximation and Interpolation
Something like this. f = @(x) exp(-x.^2); x = linspace(-1, 1, 9); G=vander(x); y=f(x); c=G\y'; f1=@(x)polyval(c,x); t=lin...

17 dagen ago | 0

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Finding top and bottom 10% of data
n=round(.1*numuel(yourMatrix)); [~,idx]=sort(yourMatrix); bottom=yourMatrix(idx(1:n)); top=yourMatrix(idx(end-*n+1:end));

17 dagen ago | 0

Converting a matrix to string
string(Z);

17 dagen ago | 0

How to plot x and y
t=0:.1:100; x=3*t; y=2t; plot(x,y);

18 dagen ago | 0

Can someone please debug my code?
You need to use some cell arrays since the number of lines is different in the loops. Also the calculation for Q has something w...

18 dagen ago | 0

Apply the same matrix index to another matrix (bootstrap for matrix processes)
g=[]; [a,b]=size(indices); for k=1:b g=[g,vector(repmat(indices(:,k),1,b)+[0:a:(b-1)*a])]; end

19 dagen ago | 0

How can I solve an equation with 4 vectors of unequal length?
Use ndgrid() g = 9.80665; mb = 1:0.5:20; r = 0.01:0.01:0.15; omega = 1800:1000:20000; omegarad =...

19 dagen ago | 1

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No reason to use symbolics. round(sum((-1).^(2:58)./(1:57).^2),4);

19 dagen ago | 0

why is my code giving me a parse error
x=0.1; %beats=A(1,30); There is no A defined and you are indexing into it! for k=1:30 A(k)=2*x*(1-x); %need 2*, if you wan...

19 dagen ago | 0

When I try to solve this equation, this message appears, how can I solve this problem?
k=2.7904; R=0.20491; syms a Eqn=a./(1+(2*k*(1-a))+(1+(2*k/3)).*(sqrt(3*(1-a))))==R;%messed equation up (need k*(1-a)) s = v...

19 dagen ago | 1

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Using fzero to find values of B for given values of A
A=5:5:25; for k=1:numel(A) fun = @(x) (1-0.5*cos(A(k))-1.2*cos(x)).^2+(0.5*sin(A(k))+1.2*sin(x)).^2 -1; B(k)=fzero(fun,1)...

19 dagen ago | 1

Get the position of the next in row and next in column in a matrix
matlab indexing is down and then across. A=[1 0 -2 0 0;2 8 0 1 0;0 0 3 0 -2;0 -3 2 0 0;1 2 0 0 -4]; a=A';%gets your indexing ...

19 dagen ago | 0