# Questions tagged [matrices]

For questions about construction and modification of matrices, objects represented by 2-dimensional arrays that are used to define linear operators within linear algebra.

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### Probability of terminating in a state in a probabilistic algorithm

Suppose i have a circular array of $n$ elements. At time $t=0$ i am in position 0 of the array. The algorithm moves left or right with probability $p=1/2$ (since the array is circular when it moves ...
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### Time complexity to find out the number of ways to parenthesize N matrices

I am trying to figure out the $time$ $complexity$ to find out the number of ways we can parenthesize $N$ $matrices$. I have approached this problem as, say if we have $N+1$ matrices then we can ...
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### Image convolution - image darkens

I'm using kernel convolution in python to blur an image, but in addition to blurring it also turns the image darker. Could someone explain why it happens? ...
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### Find if there is matrix that satisfying the following conditions

Given a matrix $A_{n\times n} = \{a_{ij}\}$ such that $a_{ij}$ is a non-negative number and given 2 vectors $(r_1,r_2,...,r_n)$ , $(c_1,c_2,...,c_n)$ such that $r_i,c_i\in \mathbb{Z}$ define an ...
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### Enumerating special Matrices

Is there an efficient algorithm for enumerating binary $n\times n$ matrices which are such that each row has 𝑘 1's and each column also has 𝑘 1's? Related - https://math.stackexchange.com/questions/...
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### How much can matrix multiplication algorithm be parallelized?

You all may know that simple Matrix Multiplication algorithm: ...
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### Algorithm to find a all valid matrix permutations [closed]

I have an array of $N^2$ numbers like $a = \{ a_1,a_2, ..., a_{N^2} \}$ where all $a_i < F$ where $F$ is a fixed number. I am looking for all permutations where if I put values in $A$ in order (...
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### Could a Van Emde Boas tree be used for storing matrices?

I'm aware that typical techniques to store matrices in sparse form are compressed formats or maps where the key is the pair of indices and value the value of the entry in a matrix. I was wondering if ...
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### How to find a path that connects all the dots in the matrix?

I have a matrix that consists of 0, 1, 2. 0 - dot. 1 - block. 2 - start dot (initial position in the path). I have to create a path from the start dot, that connects all the dots in the matrix and ...
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### Number of submatrices with a particular sum- Answer Explantion

I read Evgeny Kluev answer on this and was not able to understand the mechanism. Now let us understand using an example. let us say we have this matrix. ...
693 views

### Recursive definition of Matrix

Like Linked-list for Array, is there a recursive counter-part for Matrix? Is there a persistent data structure which can be used in place of Matrix in pure functional language like Haskell?