Questions tagged [algorithms]
A description of the specific steps needed to solve a particular problem in an unambiguous way, expressed in an abstract form.
587 questions
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Issues deriving a periodic basis in r^3
Math preamble
I am trying to create a functional basis for $[-1, 1]^3$ in $\mathbb{R}^3$. To this effect I take the real expression of the fourier basis and index it with an integer such that
$$\phi_i(...
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Sampling Algorithm for Maintaining Spatial Aggregation
I am currently working on a problem related to the behavior of cells in a two-dimensional space.
Let's consider a two-dimensional space composed of $n \times n$ cells, where each cell has its own ...
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How would you implement a transform similar to the Euclidean distance transform? Does it have a name?
I have a binary (B&W) image. I want to transform it like this:
Every 0 pixel remains 0.
Every 1 pixel is substituted with the radius of the biggest circle which contains this pixel but does not ...
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Algorithm to find all integer solutions in a bounded domain
I am not sure if this question has been already addressed but I could not find it.
Given a set of positive integer bounds $m_1,m_2,...,m_n$, a set $p_1,p_2,...,p_n$ of values such that $p_i\in\mathbb{...
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How is the basis change computed in alternative basis strassen's algorithm for matrix multiplication?
Crossposted on Mathematics SE
A recent paper proposed the Alternative Basis Strassen algorithm [1] for matrix multiplication, which uses 7 multiplications and 12 additions, but needs you to make a ...
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algorithm for generating all the standard Young tableaux
Is there any good algorithm for generating all the standard Young tableaux for a partition of $n$?
I want to check the hook length formula by numerical experiment. But first I need an algorithm to ...
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Algorithm to compute the canonical form of a (skew-)symmetric matrix pencil
Let $A, B$ be $2n \times 2n$ complex skew-symmetric matrices. There exists a canonical form for the pencil $A - \lambda B$, related to the Kronecker canonical form (which itself is a generalization of ...
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Why does this implementation of the Block Tridiagonal Thomas algorithm give such large errors?
See below my attempt at implementing the block tridiagonal thomas algorithm. If you run this however, you get a relatively large (10^-2) error in the block TMDA compared to the np direct solve (10^-15)...
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Looking for a numerical algorithm or library to calculate derivatives of degenerate eigenvalues
There is a well known result to easily calculate the derivative of non degenerate eigenvalues :
$$ v_p^T \frac{dA}{dx} v_p = \frac{de_p}{dx} \space\space \space(1)$$
But when they are degenerate, how ...
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Running algorithms in package EKHAD in Maple [closed]
The EKHAD package from the book A=B contains many effective algorithms. I want to use one of them in Maple, but I have troubles with the command read.
I saved the ...
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How one uses computer to prove an inequality?
Source: https://keskustelu.suomi24.fi/t/18574666/kinkkinen-epayhtalo-taas
I have heard that there is a proof that $ \frac{x}{\sqrt{y^2 + 15 xz}} + \frac{y}{\sqrt{z^2 + 15 xy}} + \frac{z}{\sqrt{x^2 + ...
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Translating Householder formulas to the complex case
I'm currently trying to implement a algorithm from Burden's Numerical Analysis described in Chapter 9.4. The algorithm calculates for a given symmetric real matrix $A$ a unitarily equivalent symmetric ...
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Eigenvalue algorithms for small matrices
I want to write a numerical library (in C++) that provides the eigenvalues of small matrices ($3\times3$–$20\times20$) for my line of work.
I read a little bit of literature and the consensus is ...
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Guidelines for image detection model for static sample
I have 20,000 plus images of art (paintings, sculptures, jars, etc) stored in a data base. The actual pieces are distributed in multiple warehouses. Ideally, the physical pieces SHOULD have a sticker ...
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What is fastest method for finding the minimum and maximum eigenvalues of a (possibly very large) symmetric matrix?
What is the best way to find the extreme eigenvalues - in order to find the spectral radius - of a general real dense symmetric matrix?
Looking at similar questions e.g.: What's the most efficient ...
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