Questions tagged [sketching]
8 questions
7
votes
0 answers
What is the correct way to determine the width and depth of a count-min sketch?
The width (number of registers) and depth (number of hash functions) of a Count-Min sketch determine the accuracy of counts retrieved.
I've found two different methods for calculating the width ($w$) and depth ($d$).
First Method
The clearest…
Matthew Murdoch
- 171
- 1
- 6
4
votes
0 answers
Is this a known question in matrix sketching?
Say one has a $D \times n$ matrix $A$ all of whose entries are non-zero. One wants a method which will look at each of the columns of $A$ one by one and create new $m \ll D $ dimensional columns and stack them up as a matrix $A'$ of dimension $m…
Student
- 173
- 8
4
votes
3 answers
Integer set disjointness query on sketches with something like homomorphic hashing
Suppose I have two sets of integers $A$ and $B$ and I have a sketch data structure described by a function $\mathsf{sketch}_n : \mathcal{P}(\mathbb{Z}) \to 2^n$ that returns a bitstring of size $n$. These sketches can be checked for disjointness…
taktoa
- 384
- 1
- 16
2
votes
0 answers
Different properties of Heavy-Hitters and Count-Min Sketch algorithms?
I'm currently using the Heavy-Hitters algorithm as described here and I'm wondering what if any space, time, accuracy, or real-world performance differences I would see if I were to switch to an implementation of Count-min Sketch plus a linked list…
Max
- 261
- 1
- 3
1
vote
1 answer
Is this a kind of "sketching"?
Say one is given a matrix (assume real and symmetric if necessary) and its $n-$dimensional columns be say $v_1,v_2,..,v_n$. Now is it possible to find a set of $d
Student
- 173
- 8
0
votes
0 answers
L1 sampling for sampling edges of a graph
I am trying to sample the edges of an undirected graph using weights. The goal is to run a sparsification algorithm on the graph. I see the point that L1 norm is best for sparsification. Can someone tell me how exactly is L1 sampling performed on…
sindhuja
- 1
- 2
0
votes
0 answers
How does hashing achieve sketching?
Given a sequence $x \in \{ 1,2,3...,\vert \Sigma \vert \}^*$ one wants to create a sketch of it say $s(x)$ of size $\frac{2c}{3}k (ln^2 k)$ bits. And that seems to be achieved as follows,
pick at random 2k-wise independent hash functions,
$h : [n…
user6818
- 1,165
- 8
- 13
0
votes
0 answers
Why is Combinatorial Sketching for Finite programs possible?
I was reading Combinatorial Sketching for Finite Programs and wanted to understand why synthesis of the sketching language was possible/feasible.
As far as I understand a partial program is transformed to the Quantified Boolean Formula…
Charlie Parker
- 3,130
- 22
- 39