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### St. Petersburg State University

52 total contributions since 2014

Professional Interests: computational physics, applied mathematics

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Eigenvalues corresponds to eigenvectors
Absolutely standard: L(k,k) ~ V(:,k). You can check it with the code: for k=1:size(h,1) disp(strcat('k=',num2str(k),'; h*v-la...

9 days ago | 0

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Subs Command for Multivariable Function
If e^ is the exponent and if you want to estimate the result numerically (from the question it is not quite clear what you want)...

10 days ago | 0

Partial least-squares regression evalutaion
The equation considered in PLS of Matlab is rather Y = X(:,:)*B(2:end,:) + repmat( B(1,:),n,1 ) + E, where: X is an n-by-...

11 days ago | 0

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Normalization of complex eigenvector
You probably want V(:,1) = V(:,1)/norm(V(:,1)); Besides, if your theta and phi are supposed to be real, the overall computatio...

16 days ago | 0

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Eigenvector without calling eigenvalues
This is not an error but a warning that you do not use the eigenvalues, which influences nothing. If you want to avoid it, subst...

16 days ago | 0

Can I check if factored and expanded polynomial forms are equal?
simplify((w^2-k^2) - (w+k)*(w-k)) ans = 0 expand((w+k)*(w-k)) ans = w^2 - k^2 factor(w^2-k^2) ans = [ -1, k - w...

16 days ago | 0

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How to call some object handle from opening function of figure?
u0=findobj('Tag','lst1','Style','listbox','Parent',gcf); % search for all the object properties you used to identify it set(u0,...

17 days ago | 0

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Submitted

Wigner 3j-6j-9j
Wigner 3j-, 6j-, 9j-symbols

Find orthogonal complement for given matrix
B=null(A'); The matrix transposing is important!

18 days ago | 1

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How can I write a loop, which can make the parameter "V" change with a cyclic variable "i"?
Use Matlab functions "strcat" and "num2str" within a loop.

19 days ago | 0

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How do I calculate acceleration with velocity and the code given?
% sample data t=0:0.1:10; % time x=3+2*t+t.^2; % coordinate [t,ind]=sort(t); % in a case time is not in an ascending order ...

23 days ago | 0

How to assign numbers to letters of the alphabet. Ex. A/a=1 B/b=2
The ASCII codes can be found with the function double double('A'); 65 If you want to get its ordinal number in the alphabet, ...

29 days ago | 0

How to sum columns of a matrix in MATLAB in specified number of columns?
B=squeeze( sum( reshape(A,size(A,1),10,[]) ,2) );

1 month ago | 0

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Create a gaussian from x values
L=20; V = linspace(0,L,301); sigma = L/20; T0 = exp(-((V-mean(V))/sigma).^2/2); plot(V,T0);

1 month ago | 1

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extract a double array to multiple arrays
b1=aa(1:4:end); b2=aa(2:4:end); b3=aa(3:4:end); b4=aa(4:4:end);

1 month ago | 1

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Importing Latex Code into Matlab Scripts
In live script, go to \insert\Equation\Latex equation or just press Cntrl+Shift+L or type your Latex equation embraced by \$ symb...

1 month ago | 0

Submitted

DigBit
Image Digitizer: Turn your scanned plots to the numeric form

How can I calculate the integral2 using sum of prod?
symprod does not support the element-wise multiplication, which is needed for integral2. You sholuld probably define your fun v...

1 month ago | 1

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sorting 2 array based on elements of other array
[A,ind]=sort(A); B=B(ind);

1 month ago | 0

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How to find the maximum distance between two curves?
(1) Specify, what do you mean by the distance between curves. If this is the distance between any points of them, a special (tho...

2 months ago | 2

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New to Matlab- How to import a text file for analysis that contains numbers and characters?
If you need it only once (or few times), use the Import utility of Matlab (Home\Import Data - a green downward arrow); chose the...

2 months ago | 0

help speeding up an incrementing loop
At the first glance, you can replace numerator=0; for k = 1:n_trc numerator = nume...

2 months ago | 0

How to find the vertical height of an ellipse/y axis length of ellipse.
In fact, the height and the width of an ellipse can be easily and more accurately found analytically. Here is Matlab program rea...

2 months ago | 1

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How to expand the Gaussian Kernel into series of eigenfunctions?
Fitst of all, you should specify --nothing can be done with an arbtrary function. Then, you can try to calculate the integrals a...

2 months ago | 1

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Turn function to zero when it reach specific value.
x = linspace (0,180,1800); y = 1. * ((exp (-0.01 .* x)) .* (sin (x)-(x .* cos (x / 2)))); Pu = 30; y(find(y>=Pu,1):end)=0; ...

2 months ago | 0

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How to show part of a nested structure as a vector?
sn='seine_1'; % sn=fieldnames(all_seines); % sn=sn{1}; nm=fieldnames(all_seines.(sn)); N=numel(nm); A=zeros(N,1); for k=...

2 months ago | 0

Values over 1000 use e
read matlab help on the "format" command. try "format longg".

2 months ago | 0

how to create Chi squared distribution using mean and variance?
see https://www.mathworks.com/help/stats/chi-square-distribution-1.html

2 months ago | 0

Not spotting where/how index exceeds number of array elements
Is this what you want? Live script vesion is attached. xmesh = linspace(0.01,0.05,5); solinit = bvpinit(xmesh, @guess); sol...

2 months ago | 0

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Solved

generate the matrix
given a value n (say 4) - generate the matrix like below; y= [0 1 2 3 4; -1 0 1 2 3; ...

2 months ago